Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T5059--91
Guidelines for Quality Control of Special Processes
Published on 1991-05-17
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implemented on 1992-07-01
Mechanical Industry Standard of the People's Republic of China
Guidelines for Quality Control of Special Processes
1 Subject Content and Scope of Application
JB/T5059---9T
This standard specifies the basic principles and control contents that should be followed when quality control is performed on special processes in machine manufacturing. This standard is applicable to the quality control of special processes of mechanical and electronic enterprises of various production types. This standard only specifies the general principles and requirements for quality control of various special processes, and puts forward the key points of quality control of several typical special processes. The specific requirements or special requirements for quality control of various processes or products should be implemented by compiling special process documents under the guidance of this standard.
2 Reference standards
GB4863
GB/T10300.5
JB/Z220
JB/Z187.3
JB/Z187.4
3 Terminology
Basic terminology for mechanical manufacturing process
Guide to quality management and quality system elements
General rules for process quality control
Format of process specification
Format of process documents for management
Standard for hygienic design of industrial enterprises
This standard adopts the terms and definitions in GB4863. In order to correctly apply this standard, the following terms are supplemented with reference to GB/T10300.5. 3.1 Process
The part of the process that one or a group of workers continuously completes on the same or several workpieces at a work site. 3.2 Link process
The process that plays a decisive role in product quality. It is the process that mainly forms the quality and is also the process that needs to be strictly controlled in the production process.
3.3 Special process
The processing quality of the process is not easy or cannot be fully verified through subsequent inspections and tests. This process belongs to special processes. For example, welding, heat treatment, electroplating, painting, filling (instrument industry), foaming (refrigerator industry), plastic pressing, etc., as well as several main processes in casting and forging.
4 Basic principles of quality control of special processes
4.1 The strictness of process quality control should be different depending on the type of product, purpose, user requirements, production conditions, etc. It is allowed to use different control methods in combination with the specific situation of the enterprise. 4.2 The quality control of special processes is mainly based on strong process control, supplemented by necessary multiple process inspections. The inspectors and quality assurance personnel have the responsibility and authority to supervise the on-site operations. 4.3 Starting from the process flow analysis, the main factors affecting the quality characteristics of each link (or sub-process) should be found, the control methods should be studied, and appropriate means should be equipped to carry out systematic control of the process. Special processes should follow the principle of "combining points and surfaces". On the basis of system control, key links should be controlled by points. JB/T5059-9 Approved by the Ministry of Machinery and Electronics Industry on May 17, 1991 and implemented on July 1, 1992 4.4 According to the process characteristics of the product, the test verification of the process method should be strengthened, clear technical and management documents should be formulated, and the process parameters and various factors affecting the fluctuation of the parameters should be strictly controlled to keep the process under control. 4.5 The operators and inspectors of special processes should undergo technical training and qualification certification. 4.6 The process materials and processed materials used in special processes should be strictly controlled, and re-inspections should be carried out when necessary. Various working media in use should be regularly analyzed, adjusted and replaced to ensure that their composition is within the specified range. 4.7 Qualified molds, tooling, equipment and measuring instruments must be used, and advanced detection technology and control methods must be actively adopted to quickly and accurately detect and adjust the main factors affecting quality characteristics, and strive to achieve automatic control to reduce quality fluctuations caused by human factors.
4.8 The working environment (dust, temperature, humidity, etc.) should be controlled to meet the requirements of the process documents and verified when necessary. 5 Main contents of quality control of special processes
5.1 Process procedures and technical documents
5.1.1 In addition to clarifying the process parameters, the process procedures of special processes should also make specific provisions for the control methods of process parameters, the preparation of samples, working media, equipment and environmental conditions. 5.1.2 The process procedures must be verified and approved and meet the relevant standards. Changes to the main process parameters must be fully tested and verified or qualified by experts before the documents can be changed. 5.1.3 For special processes, control points can be set at necessary links of the process flow according to the technical requirements and process characteristics of different products for key control. For the conditions for setting control points, please refer to JB/Z220. Control points can be set according to the quality characteristics of parts, processes or equipment. 5.1.4 Process quality analysis and verification should be carried out on control points to find out the main influencing factors, clarify the control methods, and conduct continuous evaluation. The process documents of control points should include the content of quality control, such as specific provisions on the control items, content, methods, test times, inspection methods, records and measurement personnel.
5.1.5 The process department shall compile original record forms and specify the requirements for filling in the forms according to the quality control requirements, including the requirements for inspection, supervision, identification and signature of process parameters and operating conditions by inspection personnel and quality assurance personnel. For example, it can compile process parameter checklists, fluctuation charts for grain size determination, heat treatment temperature rise curves for key parts, records of bath analysis and adjustment data, welding inspection cards, and resume cards for key parts. The main original record forms shall be summarized and archived, and the preservation period of the parts processing archives shall be specified for future reference. 5.1.6 Specify and implement the preparation, evaluation and approval procedures of process documents to ensure the correctness, completeness and uniformity of the documents used at the production site. The format of process regulations shall refer to the provisions of JB/Z187.3, and the format of process documents for management shall refer to the provisions of JB/Z187.4. 5.1.7 Formulate and implement the storage, use, modification and disposal system (or standard) of technical documents. The approval procedure for document modification shall be the same as that for the original document, and important changes shall be verified by tests. 5.2 Personnel training and assessment
5.2.1 The operators and inspectors of special processes must undergo regular assessment and training and hold a job operation certificate. For key positions with special requirements, personnel who have passed professional assessment, have on-site quality control knowledge and rich experience must be selected to take up the post. 5.2.2 Clearly stipulate the professional knowledge and operating skills that operators and inspectors of special processes should have, and form a technical assessment committee to conduct theoretical and practical operation assessments. All results should be filled in the assessment file, and those who pass the assessment will be issued the corresponding job operation certificate. 5.3 Equipment, instruments and process equipment
5.3.1 The equipment, instruments and process equipment (including metallurgical auxiliary tools) used in special processes must meet the requirements of the process regulations. 5.3.2 Newly manufactured, improved or overhauled equipment and instruments should be accepted according to their technical specifications, and can only be officially put into use after commissioning and certification. The process equipment must be accepted and verified (or tried) according to regulations before it can be used. 5.3.3 The equipment must be complete and matched, equipped with detection and measurement instruments for displaying (or automatically controlling) process parameters. Various instruments for monitoring should generally be set up according to their functions. If necessary, automatic recorders of process parameters and safety alarm devices should also be equipped. 5.3.4 Formulate and implement maintenance and repair of equipment and process equipment, and regular inspection and calibration systems for instruments and meters. The equipment management department shall establish technical files for equipment use, inspection, maintenance and calibration. The tooling management department shall establish technical files for the use and maintenance of major tooling. 5.3.5 The equipment and tooling of the control points shall be controlled with reference to the requirements of JB/Z220 to minimize the quality fluctuations caused by errors in equipment and tooling. 5.4 Environment JB/T5059-91 5.4.1 Environmental conditions (temperature and humidity in the plant, temperature and pressure of the cooling medium, pressure of compressed air, wind speed at the construction site, etc.) shall meet the requirements of the process technical documents.
5.4.2 The workplace should be equipped with effective air intake and exhaust systems and safety technical measures. The maximum concentration of harmful substances in the air of the factory should comply with the relevant provisions of TJ36.
5.4.3 Appropriate noise reduction or sound insulation measures should be taken for some important operating sound sources in the workshop (such as ventilators, blowers, air compressors, etc.) to control the ambient noise of the workshop below 85dB (except for pulse sound, but it should be properly controlled). ! 5.4.4 The workshop should have good self-heating lighting or lighting, and the operating station should have sufficient illumination. 5.4.5 Wastewater, waste gas and waste filter containing harmful substances must be effectively purified, and the three-degree emission standards should comply with the relevant national regulations on environmental protection.
5.4.6 The workshop should be equipped with necessary safety and protection facilities, and the work site must comply with the provisions of the fire prevention and technical safety system. 5.5 Process materials
5.5.1 The procurement documents of process materials should clearly specify the specifications, materials and technical requirements of the items. If necessary, quality assurance requirements should also be put forward.
5.5.2 Important process materials should be purchased strictly in accordance with the specified technical requirements. When the procurement department selects the site, the quality management department must organize relevant department personnel to conduct quality inspections on the supplier, and the site can only be designated after trial verification and approval. 5.5.3 The process materials entering the factory must have the qualification certificate of the manufacturing unit, and the re-married materials must be re-inspected according to regulations. Materials without qualification certificates or re-inspection failures are prohibited from entering the warehouse and use.
5.5.4 Materials that have exceeded the storage period must be re-inspected according to regulations, and the extension of use documents must be processed. They can only be used after approval. 5.5.5 Storage places and supporting facilities that meet the use requirements should be provided, and a strict system of storage, marking, distribution, use and recycling should be established. 5.5.6 Various semens, media and other materials in use must be analyzed regularly according to the requirements of technical documents to ensure that their components are within the specified range. Phase liquids and media that do not meet the technical requirements should be adjusted or replaced, and those that do not meet the requirements shall not be used in production. 5.5.7 Important process materials of new brands should be tested and verified in production, and test verification reports should be submitted. They can only be used after being identified and approved by the competent department.
5.6 Plate processing materials
5.6.1 The processed materials (raw materials, rough materials, semi-finished products, etc.) transferred to this process must comply with the provisions of technical documents and have qualified certificates. If necessary, the required technical information such as chemical composition, machine performance and test data should be attached, or random inspection and re-inspection should be carried out. 5.6.2 Formulate standards for purchased materials applicable to the production requirements of the factory, specify material specifications and technical requirements, as well as sampling, inspection items and methods for entering the factory and warehousing.
5.6.3 Important outsourced materials should be purchased from designated locations based on merit and re-inspected upon entry into the factory. When necessary, the quality assurance capabilities of the supplier should be inspected and supervised, and a technical quality file for qualified suppliers should be established. 5.6.4 A system for incoming material verification, warehousing, storage, marking, and distribution should be established and implemented conscientiously. 5.7: Process Control
5.7.1 Before processing, operators should be familiar with the process regulations and make all preparations in strict accordance with the process regulations, including inspection of equipment, materials, media, and environmental conditions, various pretreatments, sample verification of process parameters, etc., and make original records. For special key parts, the process personnel should conduct technical briefings to the operators to ensure that the operators truly master the process regulations. 5.7.2 Strictly operate in accordance with the process regulations. The clamping and placement of workpieces, the adjustment of process parameters, the extraction, inspection, and storage of samples should be carried out in accordance with the technical requirements of different materials and the relevant provisions of the process regulations. 5.7.3 The original records should be filled in carefully, truthfully and completely, and signed, processed, delivered and kept according to the prescribed procedures. 5.7.4 During the operation, close attention should be paid to the processing situation. If any problems are found, effective measures should be taken by the relevant departments or notified immediately to solve them, and original records should be made. bzxZ.net
5.7.5 Each batch of parts must be inspected for the first piece, marked, filled in the first piece record card, and signed and stamped on the record. 5.7.6 The process inspector should conduct a patrol inspection on the production site, supervise the execution of the process and the recording of the original records, spot check the processing quality of 3
JB/T5059—91
parts, keep supervision and inspection records, and urge the relevant personnel to correct the quality problems found during the patrol inspection in a timely manner. 5.7.7 For the main sub-processes in the processing of key parts, "witness points" can be set up as needed, and the quality assurance engineer who is not directly responsible for the quality shall conduct witness audits to conduct supervisory inspections on whether the operators are in a state of self-control during the process processing, whether the inspectors are in charge of their duties, whether the drawings and process documents are complete, and whether the process processing quality meets the specified requirements, so as to ensure the effectiveness of on-site quality control. 5.7.8 The storage, turnover and transportation of parts between processes shall be controlled in accordance with the fixed-location management regulations and periodic quality standards, and suitable workstations and storage and transportation equipment shall be provided to prevent damage to the parts. 5.8 Quality Inspection
5.8.1 The process quality standards shall be specified, the technical requirements, inspection items, project indicators, methods, frequency, instruments and other requirements shall be clarified, and inspection points shall be reasonably set up in the process, and inspection procedures shall be compiled. 5.8.2 Inspect semi-finished products and finished products according to technical requirements and inspection procedures, and check whether the original records are complete and filled in completely. After passing the inspection, the qualified certification document should be filled in and the qualified mark (or label) should be affixed to the designated location. 5.8.3 Strictly control non-conforming products and handle them according to the prescribed procedures. The reuse of non-conforming parts should be approved according to the prescribed procedures, and repaired, reworked and re-inspected according to relevant regulations. Reused parts should be marked with reuse marks, and the reuse and repair documents should be used as quality information circulation and archived. The inspected products, qualified products, repaired products and waste products should be marked with eye-catching signs and stacked or isolated separately. 5.9 Feedback and processing of quality information
5.9.1 Various quality inspection records, physical and chemical analysis reports, control charts, etc. of special processes must be organized and kept according to the filing system and be under inspection at any time.
5.9.2 The daily statistical report of on-site processing defect classification and other various quality problem feedback forms should be compiled and filled in. Sudden quality information should be handled in a timely manner, and the corresponding forms should be filled in.
5.9.3 A system should be formulated to promptly feedback, summarize and handle special process quality problems found in subsequent processes (including product use): and implement it conscientiously.
5.9.4 A quality improvement system should be formulated and implemented. Classify, count and analyze various quality defects according to the prescribed procedures, formulate quality improvement plans for major defect projects, and organize their implementation. If necessary, process tests should be carried out and incorporated into process regulations after the results are obtained. 6 Key points of quality control of several typical special processes This chapter combines several typical special processes and puts forward some control points. When enterprises carry out quality control of special processes, they should supplement and improve them according to the requirements of Chapter 5 and make comprehensive arrangements for the control of people, machines, materials, methods and environment (4M1E). 6.1 Quality control of heat treatment process
6.1.1 Whole process control
A quality control system for the whole process, including acceptance of incoming materials, cleaning before heat treatment, preheating, heating, heat preservation, cooling, tempering, cleaning, calibration, inspection, rust prevention and storage, should be established.
6.1.2 Control points
Through the investigation of common defects in heat treatment (deformation, cracks, white spots, overheating, overburning, decarburization, insufficient hardness, uneven hardness, poor mechanical properties, etc.), find out the main quality defects, conduct process quality factor analysis, determine the main causes and control measures on the basis of process test verification, and set up control points. At the same time, the process inspection of important key parts should be strengthened, the process documents should be refined, and key control should be carried out. 6.1.3 The influence of the quality of the previous process
The influence of the quality of the previous process of heat treatment on the final heat treatment quality should be paid attention to, and the process route and the quality control of the previous process should be arranged reasonably. For example, machining should minimize machining stress, pay attention to transition fillets, and prevent stress concentration. For shaft parts with a relatively large length-to-diameter ratio, after rough machining or semi-finishing, annealing should be arranged to eliminate internal stress to reduce heat treatment deformation and cracking. Forgings should prevent heat treatment defects caused by overheating, overheating, and too low final forging temperature.
6.1.4 Supervision of process parameters
Strengthen the detection and recording of process parameters. In general heat treatment, the heating temperature, heating rate, holding time, cooling method, cooling rate, cooling medium and temperature, furnace discharge temperature and other process parameters should be controlled. In chemical heat treatment, the carbon potential should also be strictly controlled during the carburizing process. In ion nitriding, the parameters such as ammonia temperature, holding time, and heating rate should also be controlled. It should be strictly implemented in accordance with the provisions of the process documents. For key parts, the heat treatment technology record card should be filled in to record the main process data and related service items. The operator records the data on site, and the inspector checks and signs on site. 6.1.5 Process Inspection
Strengthen the quality inspection during the process, implement the card signing degree of process flow, and any product that fails the inspection shall not be transferred. Study the correlation between the substitute quality characteristic value and the quality characteristic, and use the substitute quality characteristic value to quickly and accurately evaluate the process quality, so as to adjust the process parameters in time. For example, the quenching of high-speed steel can prevent overheating or insufficient hardness of the workpiece by measuring the grain size of the test piece (or sample) and controlling the fluctuation range of the grain size to reduce heat treatment deformation. For example, during post-forging heat treatment, white spots can be prevented from appearing on the forging by controlling the hydrogen content. 6.1.6 Tooling and Equipment
6.1.6.1. Key or main equipment should be equipped with temperature indicating instruments and alarm devices, and automatic recording should be implemented. Tooling should be designed and used reasonably and correctly, and regular management and maintenance of heat treatment tooling and equipment should be strengthened. Key tooling and equipment should be inspected daily. 6.1.6.2. Various heat treatment equipment must be inspected and maintained regularly. Heating furnaces, carburizing furnaces, nitriding furnaces and induction heating equipment should be regularly tested for process performance to ensure the uniformity of furnace temperature, uniformity of carburized layers and requirements of induction heating, and to ensure the cooling performance of various cooling equipment. Various instruments should be calibrated, corrected and inspected weekly. 6.1.6.3 The integrity rate of various heat treatment equipment should be continuously improved, and advanced equipment and control instruments should be actively adopted to realize automatic control of heat treatment quality disks.
6.1.7 Medium
The heating medium (oil, gas, bath salt, etc.) and cooling medium (air, water, salt water, kerosene, synthetic ignition agent, etc.) and protective gas (hydrogen, nitrogen, etc.) shall meet the requirements of relevant technical standards and meet the required heat treatment heating and cooling performance, do not contain excessive harmful substances, and have no corrosion or other harmful effects on the parts. The various media in use must be analyzed regularly according to the relevant technical requirements. The media that do not meet the technical requirements should be adjusted or replaced, and those that do not meet the requirements shall not be used in production. 6.2 Welding process quality control
6.2.1 Whole process control
A quality control system for the whole process from material supply, pre-welding preparation (pretreatment, layout, blanking, groove processing, hot and cold forming, etc.), assembly welding (assembly, welding), post-welding treatment (shot peening, heat treatment, etc.) and finished product inspection should be established. 6.2.2 Welding seam grade
Based on the stress condition, importance, failure hazard and other factors of the welded parts, the welds are divided into three grades, and corresponding marks are made in the design and process documents.
First-grade welds: welds that bear large static loads, dynamic loads or alternating loads, weld damage will cause product failure or endanger the life safety of personnel.
Second-grade welds: welds that bear large static loads, dynamic loads or alternating loads, weld damage will reduce the performance of the product, but will not cause failure or endanger the life safety of personnel.
Third-grade welds, general welds that bear small static loads or dynamic loads. 6.2.3 Control points
First-grade welds must be focused on control, and second-grade welds can be decided whether to be focused on control based on the stability of the enterprise's process quality. Enterprises should also set up control points according to the weak links in the entire welding process (pre-welding preparation, assembly welding, and post-welding treatment) for key control. Pressure vessels should also set up supervision points (witness points and stop points) in accordance with relevant regulations. 6.2.4 Welding process assessment
Changes to welding process parameters, welding methods, and welding process parameters of first- and second-level welds included in the process regulations for the first time must first be subject to welding process assessment. A "Welding Process Assessment Management Measures" should be formulated to stipulate the conditions, purpose, content, method, responsible department, assessment report, and work procedures of process assessment. After the welding process is qualified, the important parameters of the welding method shall be recorded in the process assessment report. After approval by the enterprise's technical person in charge, the report shall be numbered and filed as the basis for formulating process regulations. Strictly implement the assessed welding specifications. 6.2.5 Welding material control
Strengthen the quality control of welding materials. Welding materials must be inspected according to the specified technical conditions before entering the factory. They can only be stored and used after they are qualified. Welding materials must be classified and stacked, and dried at the specified temperature and insulation time. The welding material warehouse must be dry and ventilated, and the temperature and humidity in the warehouse must be strictly controlled. A strict storage, disinfection, drying, distribution and recycling system should be established. 5
6.2.6 Personnel Qualification
JB/T5059—91
Strictly implement the qualification certification of welders. The qualification assessment of pressure vessel welders shall be carried out in accordance with the requirements of the boiler pressure vessel welder examination rules issued by the Ministry of Labor, and reported to the superior competent department and local labor department for approval. Welding inspectors must have more than five consecutive years of welding work experience, and have received basic knowledge training in welding inspection and passed the examination. Personnel engaged in non-destructive testing must pass the examination in accordance with the requirements of the "Qualification Examination Rules for Boiler Pressure Vessel Non-destructive Testing Personnel" of the Ministry of Labor and Personnel. 6.2.7 Equipment
Welding equipment must be complete and equipped with detection and measuring instruments or meters that display welding process parameters (current, voltage, welding speed, preheating temperature, vacuum, etc.). Welding equipment for welding first and second level welds should be equipped with an electric parameter automatic recorder to monitor and record welding process parameters according to the needs of the product. Welding equipment must be tested and repaired regularly. 6.2.8 Process and supervision
6.2.8.1 Before welding, weldments and welding materials must be pre-treated (surface cleaning, drying, etc.) as required, and welded within the specified time. 6.2.8.2 For the first and second level welding chains or products with special requirements, welding test plates shall be set up, and the welding test plates shall be inspected according to the product test plate inspection regulations. Only after they are qualified can the products be welded.
6.2.8.3 For the first and second level weld products, intermediate inspection stations shall be set up to conduct process inspections in the processes of cutting and assembly. At the same time, the welded products shall be finally inspected. To ensure that the process quality of cutting and assembly can meet the quality requirements of welding, so that the quality of the final product is qualified. 6.2.8.4 Strengthen the quality supervision of the welding process, and regularly or on a tour, inspect the welding quality of weldments and the main factors affecting welding quality (such as current, voltage, welding speed, flux temperature of wave soldering, solder density, etc.). 6.2.8.5 For first-level, second-level or specially specified fusion welding seams, the welding specifications shall be controlled, and the specification parameters and product inspection results shall be recorded in the fusion welding inspection card. The process parameters shall be filled in by the welder, and the inspection results shall be filled in by the inspector. The inspection card shall be filed. For first-level, second-level or specially specified resistance welding seams, before welding and during welding, each batch of parts shall be subjected to process tests to verify the welding parameters. The results of each process test shall be recorded in the resistance welding inspection card. The process parameters shall be filled in by the welder, and the inspection results shall be filled in by the inspector. The inspection card shall be filed.
The first-level and second-level welds shall be marked with the welder and inspector's stamps at the specified positions. 6.2.9 Quality control of welding heat treatment
All welds that require preheating before welding, intermediate heat treatment, and post-weld heat treatment must be heat treated in strict accordance with the corresponding heat treatment process specifications. The main heat treatment parameters shall be automatically recorded by the instrument or recorded by the operator on a tour. The records shall be filed after being signed by the full-time inspector and the responsible engineer.
6.2.10 Environmental conditions
The temperature and humidity in the welding workshop, the wind speed in the workplace, the pressure and temperature of the cooling water of the machine, the pressure of the compressed air for the welding equipment, etc. shall all meet the requirements of the process documents. The welding site must comply with the provisions of the fire prevention and technical safety system. 6.3 Casting process quality control
6.3.1 Whole process control
A quality control system for the whole process from material supply, chess mold tooling manufacturing and finishing, sand treatment, core making, molding, drying, box assembly, smelting, porcelain injection, cleaning, heat treatment, polishing and coating, defect repair and casting quality inspection should be established. 6.3.2 Control points
Starting from the analysis of the general casting quality characteristics, find out the key links that affect the quality of the casting in the whole process flow, set up process control points, and at the same time, for key parts, strengthen the process inspection, refine the process, conduct process briefing to the operator, and implement key control. The control items, requirements and methods should be clearly defined for the control points, and experienced personnel and effective testing instruments should be provided. For example, in order to control the quality of molten iron, process control points can be set up in key links such as cupola charging and electric furnace refining. 6.3.3 Molding
Strengthen the preparation and performance measurement of source materials such as mold (core) sand, coating and their mixtures; strictly inspect the intermediate processes such as casting, core and mold matching: control and measure the proportion of self-molding sand, and the drying temperature and time of mold and core, and the residual moisture of the main parts should also be measured: reasonably place the chill, top casting, pressure iron, etc. All links in the process of core making, molding and box assembly should be controlled more strictly, and the equipment and tooling management should be strengthened to ensure the molding quality.
6.3.4 Furnace Charge Formula
JB/T505991
In addition to strengthening the re-inspection and pretreatment of purchased materials, different formulas should be studied for pig iron, ferroalloys and coke of different origins, different grades and different element contents, so as to control the chemical composition of molten iron within the specified range with the best ratio. 6-3.5 Melting and Porcelain Casting
6.3.5.1 Strengthen the control of the main factors in the melting and porcelain casting process, such as the bottom coke height, furnace charge weighing, charging sequence and time, air volume and pressure, rapid analysis of molten iron, temperature measurement in front of the furnace, overflow and violation of burning and casting, and insulation time of castings, so that the chemical composition, metallographic structure and mechanical properties of the cast iron parts meet the requirements of the specifications.
6.3.5.2 Melt-clear carbon control
In order to complete the tasks of dephosphorization, gas, inclusions and alloying, the open-hearth furnace and electric furnace must control the reasonable melt-clear carbon content according to the standards of different steel grades.
8.3.5.3 Strengthen the control of the main factors in the melting and pouring process, such as the open-hearth ore decarburization rate, pure boiling decarburization rate and time, the oxidation decarburization of the electric furnace, the reduction method and time, the carbon content of the molten steel, the molten steel concentration, the drawing temperature, the slag composition, the tapping temperature, the tapping temperature of each package of molten steel when pouring large pieces in multiple packages, the ladle span, the pouring temperature, the steel insulation time, etc., so that the chemical composition, metallographic structure and mechanical properties of the steel castings meet the requirements of the specifications.
6.3.6 Cleaning and heat treatment
Control the cutting temperature of the day mouth, the sand base of the cleaning, the casting temperature during the welding repair of the casting, the furnace temperature, time and loading position during the tempering (annealing) of the casting, so as to improve the surface quality of the casting and improve the internal structure. 6.3.7 Environmental conditions
Study the influence of environmental conditions such as climate, humidity and temperature on the casting quality, master its laws, and take corresponding measures in the process plan and task support.
6.3.8 Others
Strengthen environmental governance, do a good job in civilized production, actively adopt advanced testing and casting equipment, continuously improve working conditions, fully mobilize the enthusiasm of workers, and improve self-control ability.
6.4 Forging process quality control
6.4.1 Whole process control
A quality control system for the whole process from raw material supply, cutting, heating, forging, cooling, heat treatment, cleaning and forging quality inspection should be established.
6.4.2 Control points
Key parts and key parts determined by the importance classification of design quality characteristics, process difficulty, economic value of forgings, etc. should be focused on. At the same time, key control should also be carried out in the weak links of the whole forging process, such as setting control points in cutting and rough links. 6.4.3 Process Documents
Start with the analysis of the factors affecting the main quality defects of the parts (overburning, carbide segregation, stress concentration, cracks, dimensional tolerance, etc.), and strictly control the main influencing factors (heating temperature, holding time, furnace loading position, burner adjustment, initial forging overflow, final forging temperature, deformation degree, water gate removal amount, etc.). All common requirements should formulate various operating rules and specifications (such as steel ingot heating specifications, forging operation rules, etc.). The special requirements of different products should be specified in the process card.
6.4.4 Mold Control
New molds should be manufactured according to the requirements of the mold drawing. After passing the inspection, the initial inspection certificate will be issued. Before use, it must be tested. Only after passing the test can the final inspection certificate be issued. The mold of the repaired groove should be re-tested and a conclusion should be drawn. The tail parts of each batch of production should be marked and the size should be checked. The mold can only be returned to the warehouse after passing the test.
6.4.5 Heating
6.4.5.1 Before heating the bad material, the material brand, specification, material weight, quantity, melting furnace number or batch number should be checked. Bad materials should be placed in the work area when entering the furnace. Large bad materials should be suspended with iron pads. There should be a certain distance between the bad materials to ensure that the bad materials are heated evenly. 6.4.5.2 When heating in a diffuse flame furnace, the flame is not allowed to spray directly on the surface of the bad material. The furnace loading position should be at a certain distance from the burner. When heated to the forging temperature, the burner should be adjusted frequently to prevent the metal from overheating or overburning. JB/T5059—91
When heating in an electric furnace, the material should be kept at a certain distance from the heating element or shielding measures should be taken to prevent the metal from overheating. 6.4.5.3 The charging temperature, heating temperature, heating and holding time should be carried out in accordance with the requirements of the process regulations. The material temperature when heating the bad material should be measured by instruments, and the heating records of the bad material should be kept and filed for future reference. 6.4.5.4 When non-oxidizing or less-oxidizing heating methods are used and protective gas is used, the protective gas should not corrode or damage the heated material. 6.4.6 Forging
6.4.6.1 Before forging, the mold and tools must be preheated to the specified temperature using the correct method. During forging, the process parameters such as the initial forging temperature and the final forging temperature must be strictly controlled. The cooling of the forging should be carried out according to the cooling method specified by the process according to different materials. 6.4.6.2 During the plating operation, the operation should be strictly carried out according to the control requirements of the degree and speed of deformation of bad materials in the process regulations according to different materials and forming requirements. Pay attention to whether the deformation of bad materials is normal. If defects such as folding and cracks are found, effective measures must be taken to remove them in time. 6.4.6.3 Each sub-process in forging (drawing, rough forging, punching, hole expansion, bending, twisting, cutting, etc.) has the characteristics of continuity and restriction. Therefore, it is necessary to strengthen the quality control of each sub-process, clarify the responsibilities of each sub-process, and strictly implement the process regulations of each sub-process to ensure the quality of the final forgings.
6.4.7 Inspection
Forgings must undergo "first piece three inspections" (inspections by operators, team leaders, and inspectors). Process inspectors should conduct patrol inspections on the production site, Monitor the furnace overflow and operation conditions, and regularly check the external dimensions and surface quality of the forgings. Final inspection should be carried out after the forgings are completed, and samples should be taken from the forgings for physical and chemical tests according to the specifications, and the forger and inspector marks should be marked at appropriate locations. 6.4.8 Environmental conditions
The minimum temperature of the workshop equipped with hydraulic presses, high-speed hammers, hydraulically linked counter-blow hammers, hydraulic screw presses and other hydraulic transmission devices should not be lower than 10°C. When transporting cold ingots in winter, there should be certain control measures in the process to prevent direct heating of negative temperature metal. When transporting hot ingots in winter, when removing the insulation cover and unloading the hot ingots, avoid direct blowing of cold air on the hot ingots. 6.5 Quality control of electroplating process
65.1 Whole process control
The quality characteristics of the plated parts are affected by the work quality of each link in the whole process. For example, "low hydrogen embrittlement" is affected by pickling, electroplating and hydrogen driving. Therefore, a quality control system should be established for the entire process from material supply, pre-plating treatment, electroplating, post-plating treatment, to finished product inspection. 6.5.2 Control points
Starting from the analysis of the general quality characteristics of plated parts, find out the key links that affect the quality of plated parts and the links where quality problems occur repeatedly in the process flow, and establish control points for key control. Find out the main influencing factors and clearly define the control items, content and methods. Generally, control points are set up in the raw material inspection, corrosion, electroplating, hydrogen driving and passivation links. 6.15.3 Process documents
Different electroplated parts should prepare appropriate process documents according to their characteristics. For different process flows, the composition and ratio of the treatment liquid and the electroplating solution, the electroplating The process parameters (current density, working temperature, time, pH value, etc.) and operation methods of plating should be actively orthogonal tested to find the most optimal process solution, improve the process level, and accumulate mature process experience. 6.5.4 Process materials
6.5.4.1 Strict quality standards must be formulated for chemical raw materials, metal anodes and other raw materials used in the process, and the specifications, grades, purity levels, and maximum allowable impurity content of raw materials must be clearly specified. When the purity of commercially available raw materials does not meet the quality requirements, detailed purification methods and quality requirements should be determined through experiments.
0.5.4.2 The change or substitution of raw materials should be approved by the technical department after passing the small test, pilot test and small batch test, and then reviewed by the technical section chief and approved by the chief engineer or the director in charge before it can be put into use. 6.5.4.3 The raw materials purchased into the factory must undergo strict quality certification document acceptance and sampling analysis inspection, and can only be put into storage after passing the acceptance.
6.5.4.4 Raw materials should be kept separately according to their properties, and raw materials of different specifications and purity should not be mixed. There should be a special management system and isolated storage system for flammable and explosive chemical raw materials. The storage warehouse should have ventilation and heat dissipation conditions that meet the requirements, and be equipped with corresponding fire protection measures. Highly toxic substances used in electroplating should be stored in a special highly toxic substance warehouse, which must be managed by two people with two locks, one of whom should be the person in charge of the factory security department. A strict system for warehousing, storage, and material collection should be established. .82 Control points
Key parts and critical parts determined by the importance classification of design quality characteristics, process difficulty, economic value of forgings, etc. should be subject to key control. At the same time, key control should also be carried out in the weak links of the entire forging process, such as setting control points in the blanking and roughing links. 6.4.3 Process documents
Start with the analysis of the influencing factors of the main quality defects of the parts (overburning, carbide segregation, stress concentration, cracks, dimensional deviation, etc.), and strictly control the main influencing factors (heating temperature, holding time, furnace loading position, burner adjustment, initial forging overflow, final forging temperature, deformation degree, water gate removal amount, etc.). All common requirements should formulate various operating rules and specifications (such as ingot heating specifications, forging and pressing operating rules, etc.). Special requirements for different products should be specified in the process card.
6.4.4 Mould control
New moulds shall be manufactured according to the requirements of the mould drawing. After passing the inspection, the initial inspection certificate shall be issued. Before use, the mould must be tested. Only after passing the test can the final inspection certificate be issued. The mould of the repaired groove shall be re-tested and a conclusion shall be drawn. The tail pieces of each batch of production shall be marked and the size shall be checked. The mould can only be returned to the warehouse after passing the test.
6.4.5 Heating
6.4.5.1 Before heating the bad material, the material brand, specification, material weight, quantity, melting furnace number or batch number shall be checked. When the bad material is put into the furnace, it shall be placed in the working area. Large bad materials shall be suspended with iron pads. There shall be a certain distance between the bad materials to ensure that the bad materials are heated evenly. 6.4.5.2 When heating in a diffuse flame furnace, the flame is not allowed to be sprayed directly on the surface of the bad material. The furnace loading position shall be at a certain distance from the burner. When heating to the forging temperature, the burner shall be adjusted frequently to avoid overheating or overburning of the metal. JB/T5059—91
When heating in an electric furnace, the material should be kept at a certain distance from the heating element or shielding measures should be taken to prevent the metal from overheating. 6.4.5.3 The charging temperature, heating temperature, heating and holding time should be carried out in accordance with the requirements of the process regulations. The material temperature when heating the bad material should be measured by instruments, and the heating records of the bad material should be kept and filed for future reference. 6.4.5.4 When a non-oxidizing or less-oxidizing heating method is used and a protective gas is used, the protective gas should not corrode or damage the heated bad material. 6.4.6 Forging
6.4.6.1 Before forging, the molds and tools must be preheated to the specified temperature using the correct method. During forging, the process parameters such as the initial forging temperature and the final forging temperature must be strictly controlled. The cooling of the forgings should be carried out according to the cooling method specified in the process according to different materials. 6.4.6.2 During the plating operation, the operation should be strictly carried out according to the different materials and forming requirements and the control requirements of the deformation degree and deformation speed of the bad materials in the process regulations. Pay attention to whether the deformation of the bad materials is normal. If defects such as folding and cracks are found, effective measures must be taken to remove them in time. 6.4.6.3 Each sub-process in forging (drawing, rough forging, punching, hole expansion, bending, twisting, cutting, etc.) has the characteristics of continuity and restriction. Therefore, it is necessary to strengthen the quality control of each sub-process, clarify the responsibilities of each sub-process, and strictly implement the process regulations of each sub-process to ensure the quality of the final forgings.
6.4.7 Inspection
Forgings must undergo "first piece three inspections" (inspections by operators, team leaders, and inspectors). Process inspectors should conduct patrol inspections on the production site, Monitor the furnace overflow and operation conditions, and regularly check the external dimensions and surface quality of forgings. Final inspection should be carried out after the forgings are completed, and samples should be taken from the forgings for physical and chemical tests according to the specifications, and the forger and inspector marks should be marked at appropriate locations. 6.4.8 Environmental conditions
The minimum temperature of the workshop equipped with hydraulic presses, high-speed hammers, hydraulically linked counter-blow hammers, hydraulic screw presses and other hydraulic transmission devices should not be lower than 10°C. When transporting cold ingots in winter, there should be certain control measures in the process to prevent direct heating of negative temperature metal. When transporting hot ingots in winter, when removing the insulation cover and unloading the hot ingots, avoid direct blowing of cold air on the hot ingots. 6.5 Quality control of electroplating process
65.1 Whole process control
The quality characteristics of the plated parts are affected by the work quality of each link in the whole process. For example, "low hydrogen embrittlement" is affected by pickling, electroplating and hydrogen driving. Therefore, a quality control system should be established for the entire process from material supply, pre-plating treatment, electroplating, post-plating treatment, to finished product inspection. 6.5.2 Control points
Starting from the analysis of the general quality characteristics of plated parts, find out the key links that affect the quality of plated parts and the links where quality problems occur repeatedly in the process flow, and establish control points for key control. Find out the main influencing factors and clearly define the control items, content and methods. Generally, control points are set up in the raw material inspection, corrosion, electroplating, hydrogen driving and passivation links. 6.15.3 Process documents
Different electroplated parts should prepare appropriate process documents according to their characteristics. For different process flows, the composition and ratio of the treatment liquid and the electroplating solution, the electroplating The process parameters (current density, working temperature, time, pH value, etc.) and operation methods of plating should be actively orthogonal tested to find the most optimal process solution, improve the process level, and accumulate mature process experience. 6.5.4 Process materials
6.5.4.1 Strict quality standards must be formulated for chemical raw materials, metal anodes and other raw materials used in the process, and the specifications, grades, purity levels, and maximum allowable impurity content of raw materials must be clearly specified. When the purity of commercially available raw materials does not meet the quality requirements, detailed purification methods and quality requirements should be determined through experiments.
0.5.4.2 The change or substitution of raw materials should be approved by the technical department after passing the small test, pilot test and small batch test, and then reviewed by the technical section chief and approved by the chief engineer or the director in charge before it can be put into use. 6.5.4.3 The raw materials purchased into the factory must undergo strict quality certification document acceptance and sampling analysis inspection, and can only be put into storage after passing the acceptance.
6.5.4.4 Raw materials should be kept separately according to their properties, and raw materials of different specifications and purity should not be mixed. There should be a special management system and isolated storage system for flammable and explosive chemical raw materials. The storage warehouse should have ventilation and heat dissipation conditions that meet the requirements, and be equipped with corresponding fire protection measures. Highly toxic substances used in electroplating should be stored in a special highly toxic substance warehouse, which must be managed by two people with two locks, one of whom should be the person in charge of the factory security department. A strict system for warehousing, storage, and material collection should be established. .82 Control points
Key parts and critical parts determined by the importance classification of design quality characteristics, process difficulty, economic value of forgings, etc. should be subject to key control. At the same time, key control should also be carried out in the weak links of the entire forging process, such as setting control points in the blanking and roughing links. 6.4.3 Process documents
Start with the analysis of the influencing factors of the main quality defects of the parts (overburning, carbide segregation, stress concentration, cracks, dimensional deviation, etc.), and strictly control the main influencing factors (heating temperature, holding time, furnace loading position, burner adjustment, initial forging overflow, final forging temperature, deformation degree, water gate removal amount, etc.). All common requirements should formulate various operating rules and specifications (such as ingot heating specifications, forging and pressing operating rules, etc.). Special requirements for different products should be specified in the process card.
6.4.4 Mould control
New moulds shall be manufactured according to the requirements of the mould drawing. After passing the inspection, the initial inspection certificate shall be issued. Before use, the mould must be tested. Only after passing the test can the final inspection certificate be issued. The mould of the repaired groove shall be re-tested and a conclusion shall be drawn. The tail pieces of each batch of production shall be marked and the size shall be checked. The mould can only be returned to the warehouse after passing the test.
6.4.5 Heating
6.4.5.1 Before heating the bad material, the material brand, specification, material weight, quantity, melting furnace number or batch number shall be checked. When the bad material is put into the furnace, it shall be placed in the working area. Large bad materials shall be suspended with iron pads. There shall be a certain distance between the bad materials to ensure that the bad materials are heated evenly. 6.4.5.2 When heating in a diffuse flame furnace, the flame is not allowed to be sprayed directly on the surface of the bad material. The furnace loading position shall be at a certain distance from the burner. When heating to the forging temperature, the burner shall be adjusted frequently to avoid overheating or overburning of the metal. JB/T5059—91
When heating in an electric furnace, the material should be kept at a certain distance from the heating element or shielding measures should be taken to prevent the metal from overheating. 6.4.5.3 The charging temperature, heating temperature, heating and holding time should be carried out in accordance with the requirements of the process regulations. The material temperature when heating the bad material should be measured by instruments, and the heating records of the bad material should be kept and filed for future reference. 6.4.5.4 When a non-oxidizing or less-oxidizing heating method is used and a protective gas is used, the protective gas should not corrode or damage the heated bad material. 6.4.6 Forging
6.4.6.1 Before forging, the molds and tools must be preheated to the specified temperature using the correct method. During forging, the process parameters such as the initial forging temperature and the final forging temperature must be strictly controlled. The cooling of the forgings should be carried out according to the cooling method specified in the process according to different materials. 6.4.6.2 During the plating operation, the operation should be strictly carried out according to the control requirements of the degree and speed of deformation of bad materials in the process regulations according to different materials and forming requirements. Pay attention to whether the deformation of bad materials is normal. If defects such as folding and cracks are found, effective measures must be taken to remove them in time. 6.4.6.3 Each sub-process in forging (drawing, rough forging, punching, hole expansion, bending, twisting, cutting, etc.) has the characteristics of continuity and restriction. Therefore, it is necessary to strengthen the quality control of each sub-process, clarify the responsibilities of each sub-process, and strictly implement the process regulations of each sub-process to ensure the quality of the final forgings.
6.4.7 Inspection
Forgings must undergo "first piece three inspections" (inspections by operators, team leaders, and inspectors). Process inspectors should conduct patrol inspections on the production site, Monitor the furnace overflow and operation conditions, and regularly check the external dimensions and surface quality of the forgings. Final inspection should be carried out after the forgings are completed, and samples should be taken from the forgings for physical and chemical tests according to the specifications, and the forger and inspector marks should be marked at appropriate locations. 6.4.8 Environmental conditions
The minimum temperature of the workshop equipped with hydraulic presses, high-speed hammers, hydraulically linked counter-blow hammers, hydraulic screw presses and other hydraulic transmission devices should not be lower than 10°C. When transporting cold ingots in winter, there should be certain control measures in the process to prevent direct heating of negative temperature metal. When transporting hot ingots in winter, when removing the insulation cover and unloading the hot ingots, avoid direct blowing of cold air on the hot ingots. 6.5 Quality control of electroplating process
65.1 Whole process control
The quality characteristics of the plated parts are affected by the work quality of each link in the whole process. For example, "low hydrogen embrittlement" is affected by pickling, electroplating and hydrogen driving. Therefore, a quality control system should be established for the entire process from material supply, pre-plating treatment, electroplating, post-plating treatment, to finished product inspection. 6.5.2 Control points
Starting from the analysis of the general quality characteristics of plated parts, find out the key links that affect the quality of plated parts and the links where quality problems occur repeatedly in the process flow, and establish control points for key control. Find out the main influencing factors and clearly define the control items, content and methods. Generally, control points are set up in the raw material inspection, corrosion, electroplating, hydrogen driving and passivation links. 6.15.3 Process documents
Different electroplated parts should prepare appropriate process documents according to their characteristics. For different process flows, the composition and ratio of the treatment liquid and the electroplating solution, the electroplating The process parameters (current density, working temperature, time, pH value, etc.) and operation methods of plating should be actively orthogonal tested to find the most optimal process solution, improve the process level, and accumulate mature process experience. 6.5.4 Process materials
6.5.4.1 Strict quality standards must be formulated for chemical raw materials, metal anodes and other raw materials used in the process, and the specifications, grades, purity levels, and maximum allowable impurity content of raw materials must be clearly specified. When the purity of commercially available raw materials does not meet the quality requirements, detailed purification methods and quality requirements should be determined through experiments.
0.5.4.2 The change or substitution of raw materials should be approved by the technical department after passing the small test, pilot test and small batch test, and then reviewed by the technical section chief and approved by the chief engineer or the director in charge before it can be put into use. 6.5.4.3 The raw materials purchased into the factory must undergo strict quality certification document acceptance and sampling analysis inspection, and can only be put into storage after passing the acceptance.
6.5.4.4 Raw materials should be kept separately according to their properties, and raw materials of different specifications and purity should not be mixed. There should be a special management system and isolated storage system for flammable and explosive chemical raw materials. The storage warehouse should have ventilation and heat dissipation conditions that meet the requirements, and be equipped with corresponding fire protection measures. Highly toxic substances used in electroplating should be stored in a special highly toxic substance warehouse, which must be managed by two people with two locks, one of whom should be the person in charge of the factory security department. A strict system for warehousing, storage, and material collection should be established. .83 Each sub-process in forging (drawing, rough forging, punching, hole expansion, bending, twisting, cutting, etc.) has the characteristics of continuity and restriction. Therefore, it is necessary to strengthen the quality control of each sub-process, clarify the responsibilities of each sub-process, and strictly implement the process regulations of each sub-process to ensure the quality of the final forgings.
6.4.7 Inspection
Forgings must undergo "first piece three inspection
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