This standard specifies the requirements, test methods, inspection rules, marking, packaging, transportation and storage of nickel and zinc plating layers on the surface of sintered NdFeB permanent magnet materials, as well as the combined plating layers with copper and nickel as the bottom layer and nickel, tin, silver and gold as the surface layer. This standard is only applicable to the protective and decorative plating layers on the surface of sintered NdFeB permanent magnet materials. XB/T 903-2002 Electroplating layers on the surface of sintered NdFeB permanent magnet materials XB/T903-2002 Standard download decompression password: www.bzxz.net

Rare Earth Industry Standard of the People's Republic of China
XB/T 903--2002
Sintered NdFeB Permanent Magnets
Surface Electroplating Coatings
Materials of sintered neodymium iron boron permanent magnets--Electroplating coatings2002-04-26 Issued
National Development and Reform Commission Rare Earth Office Issued2002-12-01 Implementation
XB/T903-2002
This standard has no corresponding international standard at present; this standard is formulated based on the current domestic production and use situation and domestic and foreign technical data, combined with the characteristics of my country's industry. Appendix A and Appendix B of this standard are informative appendices. This standard is proposed by the National Rare Earth Standardization Technical Committee. This standard is under the jurisdiction of the National Rare Earth Standardization Technical Committee. This standard is drafted by the Wuhan Institute of Materials Protection. The main drafters of this standard are: Xie Ruibing, Zhang Hua, Cheng Hao. This standard is interpreted by the National Technical Committee for Rare Earth Standardization. 1
1 Scope
Surface plating of sintered NdFeB permanent magnet materials XB/T903—2002
This standard specifies the requirements, test methods, inspection rules and marking, packaging, transportation and storage of nickel plating and zinc plating on the surface of sintered NdFeB permanent magnet materials, as well as the combined plating with copper and nickel as the bottom layer and nickel, tin, silver and gold as the surface layer. This standard is only applicable to the protective and decorative plating on the surface of sintered NdFeB permanent magnet materials. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties to the agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all undated references, the latest versions are applicable to this standard. GB/T3138 Metal coating and chemical treatment and related process terms (neqISO2079) GB/T4955 Metal coatings - Coulometric method for coating thickness by anodic dissolution (idtISO2177) GB/T5270 Metal coatings on metal substrates (electrodeposited layers and chemically deposited layers) - Test method for adhesion strength (eqvISO2819)
GB/T10125 Artificial atmosphere corrosion test - Salt spray test (eqvISO9227) GB/T12334
Metal and other non-organic coatings - Thickness Definitions and general rules for measurement (eqvISO2064) GB/T12609
Count sampling inspection procedure for electrodeposited metal coatings and related finishes (eqvISO4519) GB/T13560-2000 Sintered NdFeB permanent magnet materials GB/T13911 Method of expression for metal coatings and chemical treatments QB/T3814-1999 Test method for appearance quality of metal coatings and chemical treatment layers of light industrial products 3 Terms and definitions
The terms and definitions established in GB/T3138 and GB/T12334 apply to this standard. 4 Information that the purchaser should provide to the surface treatment processor 4.1 Necessary information
a) This standard number;
b) The type code of the coating used;
The dimensional tolerance range before surface treatment and the dimensional tolerance requirements after surface treatment; c)
d) The brand, surface roughness and density of the substrate; e) Requirements for the appearance of the coating.
4.2 Supplementary information
If necessary, provide samples for reference and comparison; a)
Sampling inspection requirements and methods for special coatings; h)
Any special requirements or restrictions during the entire surface treatment process. c)
XB/T903—2002
5 Requirements for the substrate and preparation before plating
5.1 The structure of the substrate material should be fine, uniform, dense, and have a certain stability. There should be no cracks or pinholes visible to the naked eye on the surface. Its density shall conform to the typical value in Appendix A (Informative Appendix) of GB/T13560. When the density does not meet this requirement, it shall be confirmed by negotiation between the supplier and the buyer.
5.2 The workpieces to be surface treated can be of various shapes, and their dimensional tolerances and form and position deviations shall be those of qualified workpieces. The surface roughness shall meet the precision requirements of subsequent processing.
Differences in shape and size may lead to different requirements for the quality and dimensional tolerance of the coating. The acceptance requirements for workpieces with special shapes and large dimensional differences in different directions shall be agreed upon by the supplier and the buyer. 5.3 The size of the surface residual magnetism will affect the quality of the electroplating layer, and the supplier and the buyer shall agree in advance before the electroplating process. 5.4 In order to ensure uniform current distribution during electroplating and prevent defects caused by rolling and colliding with each other, chamfering should be performed before electroplating (see Appendix B.1).
The radius of curvature after chamfering should be in the range of 0.1mm to 0.5mm. The radius of curvature should be as large as possible without affecting the dimensional matching and final use requirements of the product. After chamfering, there should be no chipping, scratches and excessive abrasion. 5.5 Before electroplating, the plated parts should be degreased (see Appendix B.2), pickled (see Appendix B.3) and other treatments as required. 6 Coating code
The order of the type and characteristics of the coating is: coating type
Coating thickness
Coating characteristics
Coating type, the type of metal coating is represented by chemical symbols: b)
Post-treatment code
Coating thickness, the thickness of the coating is represented by a number, the unit is um, which should be immediately after the chemical symbol of the coating; coating characteristics, b is used to represent bright coating, S is used to represent semi-bright coating (see GB/T13911 for other symbols); c)
d) Post-treatment code, immediately after a black dot, C1A is used to represent zinc coating blue-white passivation, C2C is used to represent zinc coating color passivation, and At is used to represent silver and tin coating anti-tarnishing treatment.
Example 1: Zn8·C1A
indicates that 8um zinc layer is electroplated on sintered NdFeB material, and blue-white passivation treatment is applied. Example 2 Ni3Cu2Ni15b
indicates that 3um nickel layer and 2um copper layer are electroplated on sintered NdFeB material, and 15um bright nickel is electroplated on the surface. 7 Coating performance and requirements
7.1 Appearance
The coating should be uniform in color, bright or matte in appearance, clean and free of rust, yellow marks, water stains and other bad marks, the chromate passivation film on the zinc coating surface should be complete, no adhesion and whitening is allowed, and the gold coating surface should not be foggy or whitening. There should be no obvious coating defects on the main surface of the workpiece, such as blistering, pores, burrs on corners, rough surface, coating cracks or local coating absence and coating shedding and other coating defects visible to the naked eye.
During rack plating, 2 to 3 visible and unavoidable conductive contact marks of the rack are allowed on non-main surfaces, but such contact marks should not expose the substrate and should not affect the overall protective performance of the product. 7.2 Thickness
The minimum local thickness requirements of each coating under typical use environment conditions are shown in Table 1. The coating thickness is necessary to provide sufficient corrosion resistance. As the severity of the use environment increases, the coating thickness should also increase accordingly. 1) The stability of the base material can be tested according to the method in Appendix A. 2
Minimum local thickness of each coating under typical use environment conditions Coating category
Note 1: Typical use environment usually refers to the indoor environment without condensation Minimum local thickness/μm
Note 2: Minimum local thickness refers to the coating thickness of the part that can be contacted by a ball with a diameter of 20mm on the main surface: XB/T903—2002
Note 3: This standard does not specify the maximum coating thickness of nickel coating (the maximum coating thickness is agreed upon by the supplier and the buyer). The maximum coating thickness should not affect the final dimensional tolerance requirements of the workpiece. At the same time, it should be noted that nickel electroplating is a good magnetic conductive material. Too thick nickel coating will produce a shielding effect and lose magnetic properties;
Note 4: The minimum local thickness of the combined coating refers to the total thickness of each sub-coating after combination. 7.3 Corrosion resistance
The time when various coatings begin to show signs of corrosion should be greater than the requirements in Table 2. Within the time specified in Table 2, the coating is allowed to have slight discoloration, blackening and darkening, and the zinc coating passivation film is allowed to fade and slightly discolor and darken; rust, blistering, cracking, shedding, powdering and other phenomena are not allowed. Table 2 The time when various coatings begin to corrode Coating category
Post-treatment code
Neutral salt spray test
Note: Zinc coating is not subjected to wet heat test (8.3.2) and pressure vessel test (8.3.3). 7.4 Bonding strength
The coating and the substrate are well bonded and no separation should occur. 8 Test method
8.1 Appearance
The appearance inspection of the coating shall be carried out in accordance with the provisions of QB/T3814. 8.2 Thickness
Time for corrosion to begin/h
Wet and heat test
The thickness of the coating shall be determined according to the anodic dissolution coulometric method specified in GB/T4955. 8.3 Corrosion resistance test
8.3.1 Neutral salt spray test
Pressure vessel test
The neutral salt spray test of the coating shall be carried out according to the provisions of GB/T10125. A 24h continuous spray test method shall be adopted. No corrosion shall occur within the time specified in Table 2.
XB/T903—2002
8.3.2 Wet and heat test
Put the sample in a constant temperature and humidity test chamber, raise the temperature to 80C ± 2C, and keep the temperature constant for 30 minutes, spray humidification with distilled water or deionized water with a pH of 6.7 to pH 7.2, and control the relative humidity at 90% ± 3%. No corrosion shall occur within the time specified in Table 3. 8.3.3 Pressure vessel test
Put the sample into a pressure vessel filled with distilled water or deionized water with a pH of 6.7 to 7.2, heat it to 120°C ± 3°C, make the vapor pressure 0.20MPa to 0.24MPa, and maintain this temperature at a constant pressure. No corrosion shall occur within the time specified in Table 3. 8.4 Bonding strength
8.4.1 The bonding strength of the nickel electroplating layer and the combined coating with copper and nickel as the base layer shall be tested according to the thermal shock test method specified in GB/T5270, heating to 250°C, keeping warm for 1h, and cooling in cold water. 8.4.2 The bonding strength of the zinc electroplating layer can be tested by using a hard steel knife with a sharp angle of 30° to scratch a square grid with a side length of 1mm, and observe whether the coating in the grid peels off from the substrate. 9 Inspection rules
9.1 Inspection and acceptance
9.1.1 The product shall be inspected by the supplier's quality and technical supervision department to ensure that the product complies with the provisions of this standard and fill in the quality certificate. 9.1.2 The buyer shall inspect the received products in accordance with the provisions of this standard. If the inspection results do not comply with the provisions of this standard, the buyer shall report to the supplier within one month from the date of receipt and the supplier and buyer shall negotiate to resolve the issue. If arbitration is required, it may be entrusted to a unit recognized by both parties and the buyer shall jointly take samples.
9.2 Batching
Each batch shall consist of products of the same production process and the same specifications. 9.3 Inspection items
Each batch of products shall be inspected for appearance, thickness, neutral salt spray, and pressure vessel test items; the wet heat test and bonding strength test items shall be carried out when there is a dispute over the product or during regular quality inspections. 9.4 Sampling
Sampling shall be carried out according to the sampling plan agreed upon by the supply and demand parties. If the demand party does not propose a specific sampling plan, it shall be carried out in accordance with the provisions of GB/T12609. 9.5 Determination of inspection results
9.5.1 If the appearance and thickness inspection results of the coating are unqualified, the single product shall be judged as unqualified. Inspection shall be allowed piece by piece, and the qualified ones shall be delivered. 9.5.2 If the corrosion resistance and bonding strength inspection results of the coating are unqualified, double samples shall be taken from the batch of products for re-inspection of the unqualified items. If one result is still unqualified, the batch of products shall be unqualified. 10 Marking, packaging, transportation, storage
10.1 Marking
The electroplated products that have passed the inspection shall be labeled with the following content: a) Name and address of the supplier:
b) Sales
Stamp of the supplier's quality inspection department:
c) Inspection date of the supplier.
10.2 Packaging
Electroplating products should be packed with clean soft materials and kept properly. The packaging materials should not affect the performance of the coating. 10.3 Transportation and storage
The packaged products should be stored in a dry and corrosive environment, away from moisture and heat sources, and avoid direct exposure to sunlight. Handle with care during transportation.
4 Quality certificate
Each batch of products should be accompanied by a quality certificate, indicating: a)
Name of supplier;
Product name;
Batch number, number of pieces;
Results of various analysis and inspections and stamps of the technical supervision department; Number of this standard;
Inspection date;
Factory date.
XB/T903--2002
XB/T903—2002
A.1 Sample preparation
Appendix A
(Informative Appendix)
Accelerated weight loss test
Process the NdFeB workpiece into a sample of $10mm×10mm, and measure its size with an accuracy of 0.01mm. A.2 Test conditions
A.2.1 The steam pressure in the pressure vessel is 0.20MPa～0.24MPa, and the temperature is 120C±3C. A.2.2 Distilled water or deionized water with a pH of 6.7～pH7.2 is used as vaporized water in the pressure vessel. A.3 Steps
A.3.1 Wash the sample with an organic solvent (such as gasoline), and weigh it after drying. Accurate to 0.001g. A.3.2 Place it in a pressure vessel, raise the temperature to the set pressure, and maintain the temperature at a constant pressure. A.3.3 After 24 hours of testing, stop heating, discharge steam from the pressure relief valve, open the pressure vessel again, and take out the sample. A.3.4 Use an organic solvent to clean the surface corrosion. If the corrosion is serious, soak it in an organic solvent and use ultrasonic cleaning for 3min~5min, then dry it thoroughly.
A.3.5 Weigh it to an accuracy of 0.001g.
A.4 Expression of analysis results
Weight loss rate is calculated as follows:
Where:
R(%) = mo - m:
Weight loss rate, in percentage per square centimeter (%/cm\): mass of the sample before the test, in grams (g); mo-
mass of the sample after the test, in grams (g); m1
S——surface area of ​​the sample before the test, in square centimeters (cm2). o
Appendix B
(Informative Appendix)
Process Selection Guide
XB/T903-2002
Sintered NdFeB permanent magnet material is a highly active powder metallurgy material that is prone to corrosion. Therefore, when electroplating its surface, the appropriate pretreatment and electroplating process should be carefully selected. Before electroplating, sintered NdFeB permanent magnet material must undergo chamfering, degreasing, pickling, ultrasonic cleaning and other processes that can stabilize and clean the surface to obtain a coating with good bonding, low porosity and long-lasting corrosion resistance. When selecting an electroplating process, it is necessary to consider the process's protectiveness and production practicability, and also to pay attention to the impact and degree of damage that electroplating emissions will cause to the environment. The environmental conditions for the use of each electroplating layer are shown in Table B.1. Table B.1 Environmental conditions for use of each electroplating layer
Coating category
B.1 Chamfer
Post-treatment code
Description of environmental conditions for use
Exposure to indoor atmospheric environment where condensation may occur, and the appearance and internal performance must be long-term stable and the service life must be long.
Used in slightly corrosive conditions, limited corrosion resistance against short-term pollution and discoloration, used in harsher atmospheres, such as organic corrosive atmospheres; where higher corrosion resistance is required, exposed to indoor atmospheric environment where condensation may occur, and the appearance and internal performance must be long-term stable and the service life must be long.
Good appearance and weldability, used in surface weldable and electrical contact situations. Good appearance and weldability, low contact resistance, poor surface resistance to discoloration, used in surface weldable and electrical contact situations. Good decorative properties, not easy to discolor the surface, low contact resistance, high cost, used in high-reliability electronic equipment such as electrical contact and high-end decorations.
Small parts can be chamfered with a centrifugal finishing machine, while larger parts can be chamfered with a spiral vibration or centrifugal vortex finishing machine after grinding the edges with a grinding wheel. Chamfering should be carried out in a neutral or slightly alkaline medium, and acidic or corrosive media should not be used for chamfering. B.2 Degreasing
It is best to use a neutral or weakly alkaline degreasing agent. To avoid oxidation or hydrogen permeation, it is best not to perform anodic or cathodic electrolytic treatment. B.3 Pickling
Use dilute nitric acid solution or weak organic acid for short-term pickling, but do not pickle in strong halogen acid. Do not pickle in high-concentration strong acid, otherwise the material surface will be rapidly coarsened or even powdered. B.4 Ultrasonic cleaning
Ultrasonic cleaning should be carried out after each treatment process to ensure the cleaning effect and prevent contamination of the next process. B.5 Electroplating
Electroplating should use a low-corrosive plating solution, and it is best to use a multi-layer combined plating layer to meet actual usage requirements. If necessary, post-treatment can be performed to further improve corrosion resistance.1 Neutral salt spray test
Pressure vessel test
The neutral salt spray test of the coating shall be carried out in accordance with the provisions of GB/T10125. A 24h continuous spray test method shall be adopted. No corrosion shall occur within the time specified in Table 2.
XB/T903-2002
8.3.2 Wet heat test
Put the sample in a constant temperature and humidity test chamber, raise the temperature to 80°C ± 2°C, and keep the temperature constant for 30 minutes. Spray humidification with distilled water or deionized water with a pH of 6.7 to pH 7.2, and control the relative humidity at 90% ± 3%. No corrosion shall occur within the time specified in Table 3. 8.3.3 Pressure vessel test
Put the sample in a pressure vessel filled with distilled water or deionized water with a pH of 6.7 to pH 7.2, raise the temperature to 120°C ± 3°C, make the vapor pressure 0.20MPa to 0.24MPa, and maintain the temperature at a constant pressure. No corrosion shall occur within the time specified in Table 3. 8.4 Bonding Strength
8.4.1 The bonding strength of the nickel electroplating layer and the combined coating with copper and nickel as the base layer shall be tested according to the thermal shock test method specified in GB/T5270, heated to 250℃, kept warm for 1h, and then quenched in cold water. 8.4.2 The bonding strength of the zinc electroplating layer can be tested by using a hard steel knife with a sharp angle of 30° to scratch a square grid with a side length of 1mm to observe whether the coating in the grid peels off from the substrate. 9 Inspection Rules
9.1 Inspection and Acceptance
9.1.1 The product shall be inspected by the supplier's quality and technical supervision department to ensure that the product complies with the provisions of this standard and fill in the quality certificate. 9.1.2 The buyer shall inspect the received products according to the provisions of this standard. If the inspection results do not comply with the provisions of this standard, they shall be reported to the supplier within one month from the date of receipt, and the supply and demand parties shall negotiate to resolve the problem. If arbitration is required, it can be entrusted to a unit recognized by both parties, and the purchaser shall jointly take samples.
9.2 Batching
Each batch shall consist of products with the same production process and the same specifications. 9.3 Inspection items
Each batch of products shall be inspected for appearance, thickness, neutral salt spray, and pressure vessel test items; wet heat test and bonding strength test items shall be carried out when there is a dispute over the product or during regular quality inspections. 9.4 Sampling
Sampling shall be carried out according to the sampling plan agreed upon by the supply and demand parties. If the purchaser does not propose a specific sampling plan, it shall be carried out in accordance with the provisions of GB/T12609. 9.5 Determination of inspection results
9.5.1 If the appearance and thickness inspection results of the coating are unqualified, the single product shall be judged as unqualified. Inspection shall be allowed piece by piece, and those that are qualified shall be delivered. 9.5.2 If the corrosion resistance and bonding strength test results of the coating are unqualified, double samples shall be taken from the batch of products for re-testing of the unqualified items. If one result is still unqualified, the batch of products shall be unqualified. 10 Marking, packaging, transportation, storage
10.1 Marking
The electroplated products that have passed the inspection shall be labeled with the following contents: a) Name and address of the supplier:
b) Stamp of the supplier's quality inspection department:
c) Inspection date of the supplier.
10.2 Packaging
Electroplated products shall be packaged with clean soft materials and kept properly. The packaging materials shall not affect the performance of the coating. 10.3 Transportation and storage
The packaged products shall be stored in a dry and corrosive environment, away from moisture and heat sources, and avoid direct exposure to sunlight. They shall be handled with care during transportation.
4 Quality Certificate
Each batch of products shall be accompanied by a quality certificate, indicating: a)
Name of supplier;
Product name;
Batch number, number of pieces;
Results of various analyses and tests and stamps of the technical supervision department; Number of this standard;
Test date;
Date of manufacture.
XB/T903--2002
XB/T903—2002
A.1 Sample preparation
Appendix A
(Informative Appendix)
Accelerated weight loss test
Process the NdFeB workpiece into a sample of $10mm×10mm, and measure its size with an accuracy of 0.01mm. A.2 Test conditions
A.2.1 The steam pressure in the pressure vessel is 0.20MPa~0.24MPa, and the temperature is 120C±3C. A.2.2 Distilled water or deionized water with a pH of 6.7~pH7.2 is used as vaporized water in the pressure vessel. A.3 Steps
A.3.1 Wash the sample with an organic solvent (such as gasoline), and weigh it after drying. The accuracy is 0.001g. A.3.2 Put it in the pressure vessel, increase the temperature to make the pressure reach the set value, and maintain the temperature at a constant pressure. A.3.3 After 24h of the test, stop heating, discharge steam from the pressure relief valve, open the pressure vessel again, and take out the sample. A.3.4 Wash the surface corrosion with an organic solvent. If the corrosion is serious, it should be immersed in an organic solvent and cleaned with ultrasonic waves for 3min~5min, and then dried thoroughly.
A.3.5 Weigh it, the accuracy is 0.001g.
A.4 Expression of analysis results
Weight loss rate is calculated as follows:
Wherein:
R(%) = mo - m:
Weight loss rate, in percentage per square centimeter (%/cm\): mass of the sample before the test, in grams (g); mo-
mass of the sample after the test, in grams (g); m1
S——surface area of ​​the sample before the test, in square centimeters (cm2). o
Appendix B
(Informative Appendix)
Guide to process selection
XB/T903-2002
Sintered iron-boron permanent magnet material is a highly active powder metallurgy material, which is prone to corrosion. Therefore, when surface electroplating is performed on it, appropriate pretreatment and electroplating process should be carefully selected. Before electroplating, sintered NdFeB permanent magnet materials must go through chamfering, degreasing, pickling, ultrasonic cleaning and other processes that can obtain a stabilized and clean surface to obtain a coating with good bonding, low porosity and long-lasting corrosion resistance. When selecting an electroplating process, it is necessary to consider the process's protectiveness and production practicability, and also to pay attention to the impact and degree of damage that electroplating emissions will cause to the environment. The environmental conditions for the use of each electroplating layer are shown in Table B.1. Table B.1 Environmental conditions for the use of each electroplating layer
Coating category
B.1 Chamfering
Post-processing code
Description of environmental conditions for use
Exposure to an indoor atmospheric environment where condensation may occur, and the long-term stability of the appearance and internal performance and a long service life are required.
Used in slightly corrosive conditions, limited corrosion resistance against short-term pollution and discoloration, used in harsh atmospheres, such as organic corrosive atmospheres; in places requiring higher corrosion resistance, exposed to indoor atmospheric environments where condensation may occur, and requiring long-term stability of appearance and internal performance and a longer service life.
Good appearance and weldability, used in places where the surface can be welded and electrical contact. Good appearance and weldability, low contact resistance, poor surface discoloration resistance, used in places where the surface can be welded and electrical contact. Good decorative effect, not easy to discolor the surface, low contact resistance, high cost, used in high-reliability electronic equipment such as electrical contact and high-end decorations.
Small parts can be chamfered with a centrifugal finishing machine, and larger parts can be chamfered with a spiral vibration or centrifugal vortex finishing machine after grinding the edges with a grinding wheel. Chamfering should be carried out in a neutral or slightly alkaline medium, and acidic or corrosive media should not be used for chamfering. B.2 Degreasing
It is advisable to carry out in a neutral or weakly alkaline degreasing agent. To avoid oxidation or hydrogen permeation, it is best not to perform anodic or cathodic electrolytic treatment. B.3 Pickling
Use dilute nitric acid solution or weak organic acid for short-term pickling, but do not pickle in strong halogen acid, and avoid pickling in high-concentration strong acid, otherwise, the material surface will be rapidly coarsened or even powdered. B.4 Ultrasonic cleaning
Ultrasonic cleaning should be carried out after each treatment process to ensure the cleaning effect and prevent contamination of the next process. B.5 Electroplating
Electroplating should use a low-corrosive plating solution, and it is best to use a multi-layer combined coating to meet actual use requirements. If necessary, post-treatment can be performed to further improve corrosion resistance.1 Neutral salt spray test
Pressure vessel test
The neutral salt spray test of the coating shall be carried out in accordance with the provisions of GB/T10125. A 24h continuous spray test method shall be adopted. No corrosion shall occur within the time specified in Table 2.
XB/T903-2002
8.3.2 Wet heat test
Put the sample in a constant temperature and humidity test chamber, raise the temperature to 80°C ± 2°C, and keep the temperature constant for 30 minutes. Spray humidification with distilled water or deionized water with a pH of 6.7 to pH 7.2, and control the relative humidity at 90% ± 3%. No corrosion shall occur within the time specified in Table 3. 8.3.3 Pressure vessel test
Put the sample in a pressure vessel filled with distilled water or deionized water with a pH of 6.7 to pH 7.2, raise the temperature to 120°C ± 3°C, make the vapor pressure 0.20MPa to 0.24MPa, and maintain the temperature at a constant pressure. No corrosion shall occur within the time specified in Table 3. 8.4 Bonding Strength
8.4.1 The bonding strength of the nickel electroplating layer and the combined coating with copper and nickel as the base layer shall be tested according to the thermal shock test method specified in GB/T5270, heated to 250℃, kept warm for 1h, and then quenched in cold water. 8.4.2 The bonding strength of the zinc electroplating layer can be tested by using a hard steel knife with a sharp angle of 30° to scratch a square grid with a side length of 1mm to observe whether the coating in the grid peels off from the substrate. 9 Inspection Rules
9.1 Inspection and Acceptance
9.1.1 The product shall be inspected by the supplier's quality and technical supervision department to ensure that the product complies with the provisions of this standard and fill in the quality certificate. 9.1.2 The buyer shall inspect the received products according to the provisions of this standard. If the inspection results do not comply with the provisions of this standard, they shall be reported to the supplier within one month from the date of receipt, and the supply and demand parties shall negotiate to resolve the problem. If arbitration is required, it can be entrusted to a unit recognized by both parties, and the purchaser shall jointly take samples.
9.2 Batching
Each batch shall consist of products with the same production process and the same specifications. 9.3 Inspection items
Each batch of products shall be inspected for appearance, thickness, neutral salt spray, and pressure vessel test items; wet heat test and bonding strength test items shall be carried out when there is a dispute over the product or during regular quality inspections. 9.4 Sampling
Sampling shall be carried out according to the sampling plan agreed upon by the supply and demand parties. If the purchaser does not propose a specific sampling plan, it shall be carried out in accordance with the provisions of GB/T12609. 9.5 Determination of inspection results
9.5.1 If the appearance and thickness inspection results of the coating are unqualified, the single product shall be judged as unqualified. Inspection shall be allowed piece by piece, and those that are qualified shall be delivered. 9.5.2 If the corrosion resistance and bonding strength test results of the coating are unqualified, double samples shall be taken from the batch of products for re-testing of the unqualified items. If one result is still unqualified, the batch of products shall be unqualified. 10 Marking, packaging, transportation, storage
10.1 Marking
The electroplated products that have passed the inspection shall be labeled with the following contents: a) Name and address of the supplier:
b) Stamp of the supplier's quality inspection department:
c) Inspection date of the supplier.
10.2 Packaging
Electroplated products shall be packaged with clean soft materials and kept properly. The packaging materials shall not affect the performance of the coating. 10.3 Transportation and storage
The packaged products shall be stored in a dry and corrosive environment, away from moisture and heat sources, and avoid direct exposure to sunlight. They shall be handled with care during transportation.
4 Quality Certificate
Each batch of products shall be accompanied by a quality certificate, indicating: a)
Name of supplier;
Product name;
Batch number, number of pieces;
Results of various analyses and tests and stamps of the technical supervision department; Number of this standard;
Test date;
Date of manufacture.
XB/T903--2002
XB/T903—2002
A.1 Sample preparation
Appendix A
(Informative Appendix)
Accelerated weight loss test
Process the NdFeB workpiece into a sample of $10mm×10mm, and measure its size with an accuracy of 0.01mm. A.2 Test conditions
A.2.1 The steam pressure in the pressure vessel is 0.20MPa~0.24MPa, and the temperature is 120C±3C. A.2.2 Distilled water or deionized water with a pH of 6.7~pH7.2 is used as vaporized water in the pressure vessel. A.3 Steps
A.3.1 Wash the sample with an organic solvent (such as gasoline), and weigh it after drying. The accuracy is 0.001g. A.3.2 Put it in the pressure vessel, increase the temperature to make the pressure reach the set value, and maintain the temperature at a constant pressure. A.3.3 After 24h of the test, stop heating, discharge steam from the pressure relief valve, open the pressure vessel again, and take out the sample. A.3.4 Wash the surface corrosion with an organic solvent. If the corrosion is serious, it should be immersed in an organic solvent and cleaned with ultrasonic waves for 3min~5min, and then dried thoroughly.
A.3.5 Weigh it, the accuracy is 0.001g.
A.4 Expression of analysis results
Weight loss rate is calculated as follows:
Wherein:
R(%) = mo - m:
Weight loss rate, in percentage per square centimeter (%/cm\): mass of the sample before the test, in grams (g); mo-
mass of the sample after the test, in grams (g); m1
S——surface area of ​​the sample before the test, in square centimeters (cm2). o
Appendix B
(Informative Appendix)
Guide to process selection
XB/T903-2002
Sintered iron-boron permanent magnet material is a highly active powder metallurgy material, which is prone to corrosion. Therefore, when surface electroplating is performed on it, appropriate pretreatment and electroplating process should be carefully selected. Before electroplating, sintered NdFeB permanent magnet materials must go through chamfering, degreasing, pickling, ultrasonic cleaning and other processes that can obtain a stabilized and clean surface to obtain a coating with good bonding, low porosity and long-lasting corrosion resistance. When selecting an electroplating process, it is necessary to consider the process's protectiveness and production practicability, and also to pay attention to the impact and degree of damage that electroplating emissions will cause to the environment. The environmental conditions for the use of each electroplating layer are shown in Table B.1. Table B.1 Environmental conditions for the use of each electroplating layer
Coating category
B.1 Chamfering
Post-processing code
Description of environmental conditions for use
Exposure to an indoor atmospheric environment where condensation may occur, and the long-term stability of the appearance and internal performance and a long service life are required.
Used in slightly corrosive conditions, limited corrosion resistance against short-term pollution and discoloration, used in harsh atmospheres, such as organic corrosive atmospheres; in places requiring higher corrosion resistance, exposed to indoor atmospheric environments where condensation may occur, and requiring long-term stability of appearance and internal performance and a longer service life.
Good appearance and weldability, used in places where the surface can be welded and electrical contact. Good appearance and weldability, low contact resistance, poor surface discoloration resistance, used in places where the surface can be welded and electrical contact. Good decorative effect, not easy to discolor the surface, low contact resistance, high cost, used in high-reliability electronic equipment such as electrical contact and high-end decorations.
Small parts can be chamfered with a centrifugal finishing machine, and larger parts can be chamfered with a spiral vibration or centrifugal vortex finishing machine after grinding the edges with a grinding wheel. Chamfering should be carried out in a neutral or slightly alkaline medium, and acidic or corrosive media should not be used for chamfering. B.2 Degreasing
It is advisable to carry out in a neutral or weakly alkaline degreasing agent. To avoid oxidation or hydrogen permeation, it is best not to perform anodic or cathodic electrolytic treatment. B.3 Pickling
Use dilute nitric acid solution or weak organic acid for short-term pickling, but do not pickle in strong halogen acid, and avoid pickling in high-concentration strong acid, otherwise, the material surface will be rapidly coarsened or even powdered. B.4 Ultrasonic cleaning
Ultrasonic cleaning should be carried out after each treatment process to ensure the cleaning effect and prevent contamination of the next process. B.5 Electroplating
Electroplating should use a low-corrosive plating solution, and it is best to use a multi-layer combined coating to meet actual use requirements. If necessary, post-treatment can be performed to further improve corrosion resistance.24MPa, maintain this temperature but keep the pressure. No corrosion phenomenon shall occur within the time specified in Table 3. 8.4 Bonding Strength
8.4.1 The bonding strength of the nickel electroplating layer and the combined plating layer with copper and nickel as the bottom layer shall be tested according to the thermal shock test method specified in GB/T5270, heated to 250℃, kept warm for 1h, and then put into cold water for rapid cooling. 8.4.2 The bonding strength of the zinc electroplating layer can be tested by using a hard steel knife with a cutting edge grinded into a 30° acute angle to scratch a square grid with a side length of 1mm to observe whether the plating in the grid peels off from the substrate. 9 Inspection Rules
9.1 Inspection and Acceptance
9.1.1 The product shall be inspected by the supplier's quality and technical supervision department to ensure that the product complies with the provisions of this standard and fill in the quality certificate. 9.1.2 The buyer shall inspect the received products according to the provisions of this standard. If the inspection results do not comply with the provisions of this standard, they shall be reported to the supplier within one month from the date of receipt, and the supply and demand parties shall negotiate to resolve the problem. If arbitration is required, it can be entrusted to a unit recognized by both parties, and the purchaser shall jointly take samples.
9.2 Batching
Each batch shall consist of products with the same production process and the same specifications. 9.3 Inspection items
Each batch of products shall be inspected for appearance, thickness, neutral salt spray, and pressure vessel test items; wet heat test and bonding strength test items shall be carried out when there is a dispute over the product or during regular quality inspections. 9.4 Sampling
Sampling shall be carried out according to the sampling plan agreed upon by the supply and demand parties. If the purchaser does not propose a specific sampling plan, it shall be carried out in accordance with the provisions of GB/T12609. 9.5 Determination of inspection results
9.5.1 If the appearance and thickness inspection results of the coating are unqualified, the single product shall be judged as unqualified. Inspection shall be allowed piece by piece, and those that are qualified shall be delivered. 9.5.2 If the corrosion resistance and bonding strength test results of the coating are unqualified, double samples shall be taken from the batch of products for re-testing of the unqualified items. If one result is still unqualified, the batch of products shall be unqualified. 10 Marking, packaging, transportation, storage
10.1 Marking
The electroplated products that have passed the inspection shall be labeled with the following contents: a) Name and address of the supplier:
b) Stamp of the supplier's quality inspection department:
c) Inspection date of the supplier.
10.2 Packaging
Electroplated products shall be packaged with clean soft materials and kept properly. The packaging materials shall not affect the performance of the coating. 10.3 Transportation and storage
The packaged products shall be stored in a dry and corrosive environment, away from moisture and heat sources, and avoid direct exposure to sunlight. They shall be handled with care during transportation.
4 Quality Certificate
Each batch of products shall be accompanied by a quality certificate, indicating: a)
Name of supplier;
Product name;
Batch number, number of pieces;
Results of various analyses and tests and stamps of the technical supervision department; Number of this standard;
Test date;
Date of manufacture.
XB/T903--2002
XB/T903—2002
A.1 Sample preparation
Appendix A
(Informative Appendix)
Accelerated weight loss test
Process the NdFeB workpiece into a sample of $10mm×10mm, and measure its size with an accuracy of 0.01mm. A.2 Test conditions
A.2.1 The steam pressure in the pressure vessel is 0.20MPa~0.24MPa, and the temperature is 120C±3C. A.2.2 Distilled water or deionized water with a pH of 6.7~pH7.2 is used as vaporized water in the pressure vessel. A.3 Steps
A.3.1 Wash the sample with an organic solvent (such as gasoline), and weigh it after drying. The accuracy is 0.001g. A.3.2 Put it in the pressure vessel, increase the temperature to make the pressure reach the set value, and maintain the temperature at a constant pressure. A.3.3 After 24h of the test, stop heating, discharge steam from the pressure relief valve, open the pressure vessel again, and take out the sample. A.3.4 Wash the surface corrosion with an organic solvent. If the corrosion is serious, it should be immersed in an organic solvent and cleaned with ultrasonic waves for 3min~5min, and then dried thoroughly.
A.3.5 Weigh it, the accuracy is 0.001g.
A.4 Expression of analysis results
Weight loss rate is calculated as follows:
Wherein:
R(%) = mo - m:
Weight loss rate, in percentage per square centimeter (%/cm\): mass of the sample before the test, in grams (g); mo-
mass of the sample after the test, in grams (g); m1
S——surface area of ​​the sample before the test, in square centimeters (cm2). o
Appendix B
(Informative Appendix)
Guide to process selection
XB/T903-2002
Sintered iron-boron permanent magnet material is a highly active powder metallurgy material, which is prone to corrosion. Therefore, when surface electroplating is performed on it, appropriate pretreatment and electroplating process should be carefully selected. Before electroplating, sintered NdFeB permanent magnet materials must go through chamfering, degreasing, pickling, ultrasonic cleaning and other processes that can obtain a stabilized and clean surface to obtain a coating with good bonding, low porosity and long-lasting corrosion resistance. When selecting an electroplating process, it is necessary to consider the process's protectiveness and production practicability, and also to pay attention to the impact and degree of damage that electroplating emissions will cause to the environment. The environmental conditions for the use of each electroplating layer are shown in Table B.1. Table B.1 Environmental conditions for the use of each electroplating layer
Coating category
B.1 Chamfering
Post-processing code
Description of environmental conditions for use
Exposure to an indoor atmospheric environment where condensation may occur, and the long-term stability of the appearance and internal performance and a long service life are required.
Used in slightly corrosive conditions, limited corrosion resistance against short-term pollution and discoloration, used in harsh atmospheres, such as organic corrosive atmospheres; in places requiring higher corrosion resistance, exposed to indoor atmospheric environments where condensation may occur, and requiring long-term stability of appearance and internal performance and a longer service life.
Good appearance and weldability, used in places where the surface can be welded and electrical contact. Good appearance and weldability, low contact resistance, poor surface discoloration resistance, used in places where the surface can be welded and electrical contact. Good decorative effect, not easy to discolor the surface, low contact resistance, high cost, used in high-reliability electronic equipment such as electrical contact and high-end decorations.
Small parts can be chamfered with a centrifugal finishing machine, and larger parts can be chamfered with a spiral vibration or centrifugal vortex finishing machine after grinding the edges with a grinding wheel. Chamfering should be carried out in a neutral or slightly alkaline medium, and acidic or corrosive media should not be used for chamfering. B.2 Degreasing
It is advisable to carry out in a neutral or weakly alkaline degreasing agent. To avoid oxidation or hydrogen permeation, it is best not to perform anodic or cathodic electrolytic treatment. B.3 Pickling
Use dilute nitric acid solution or weak organic acid for short-term pickling, but do not pickle in strong halogen acid, and avoid pickling in high-concentration strong acid, otherwise, the material surface will be rapidly coarsened or even powdered. B.4 Ultrasonic cleaning
Ultrasonic cleaning should be carried out after each treatment process to ensure the cleaning effect and prevent contamination of the next process. B.5 Electroplating
Electroplating should use a low-corrosive plating solution, and it is best to use a multi-layer combined coating to meet actual use requirements. If necessary, post-treatment can be performed to further improve corrosion resistance.24MPa, maintain this temperature but keep the pressure. No corrosion phenomenon shall occur within the time specified in Table 3. 8.4 Bonding Strength
8.4.1 The bonding strength of the nickel electroplating layer and the combined plating layer with copper and nickel as the bottom layer shall be tested according to the thermal shock test method specified in GB/T5270, heated to 250℃, kept warm for 1h, and then put into cold water for rapid cooling. 8.4.2 The bonding strength of the zinc electroplating layer can be tested by using a hard steel knife with a cutting edge grinded into a 30° acute angle to scratch a square grid with a side length of 1mm to observe whether the plating in the grid peels off from the substrate. 9 Inspection RulesbzxZ.net
9.1 Inspection and Acceptance
9.1.1 The product shall be inspected by the supplier's quality and technical supervision department to ensure that the product complies with the provisions of this standard and fill in the quality certificate. 9.1.2 The buyer shall inspect the received products according to the provisions of this standard. If the inspection results do not comply with the provisions of this standard, they shall be reported to the supplier within one month from the date of receipt, and the supply and demand parties shall negotiate to resolve the problem. If arbitration is required, it can be entrusted to a unit recognized by both parties, and the purchaser shall jointly take samples.
9.2 Batching
Each batch shall consist of products with the same production process and the same specifications. 9.3 Inspection items
Each batch of products shall be inspected for appearance, thickness, neutral salt spray, and pressure vessel test items; wet heat test and bonding strength test items shall be carried out when there is a dispute over the product or during regular quality inspections. 9.4 Sampling
Sampling shall be carried out according to the sampling plan agreed upon by the supply and demand parties. If the purchaser does not propose a specific sampling plan, it shall be carried out in accordance with the provisions of GB/T12609. 9.5 Determination of inspection results
9.5.1 If the appearance and thickness inspection results of the coating are unqualified, the single product shall be judged as unqualified. Inspection shall be allowed piece by piece, and those that are qualified shall be delivered. 9.5.2 If the corrosion resistance and bonding strength test results of the coating are unqualified, double samples shall be taken from the batch of products for re-testing of the unqualified items. If one result is still unqualified, the batch of products shall be unqualified. 10 Marking, packaging, transportation, storage
10.1 Marking
The electroplated products that have passed the inspection shall be labeled with the following contents: a) Name and address of the supplier:
b) Stamp of the supplier's quality inspection department:
c) Inspection date of the supplier.
10.2 Packaging
Electroplated products shall be packaged with clean soft materials and kept properly. The packaging materials shall not affect the performance of the coating. 10.3 Transportation and storage
The packaged products shall be stored in a dry and corrosive environment, away from moisture and heat sources, and avoid direct exposure to sunlight. They shall be handled with care during transportation.
4 Quality Certificate
Each batch of products shall be accompanied by a quality certificate, indicating: a)
Name of supplier;
Product name;
Batch number, number of pieces;
Results of various analyses and tests and stamps of the technical supervision department; Number of this standard;
Test date;
Date of manufacture.
XB/T903--2002
XB/T903—2002
A.1 Sample preparation
Appendix A
(Informative Appendix)
Accelerated weight loss test
Process the NdFeB workpiece into a sample of $10mm×10mm, and measure its size with an accuracy of 0.01mm. A.2 Test conditions
A.2.1 The steam pressure in the pressure vessel is 0.20MPa~0.24MPa, and the temperature is 120C±3C. A.2.2 Distilled water or deionized water with a pH of 6.7~pH7.2 is used as vaporized water in the pressure vessel. A.3 Steps
A.3.1 Wash the sample with an organic solvent (such as gasoline), and weigh it after drying. The accuracy is 0.001g. A.3.2 Put it in the pressure vessel, increase the temperature to make the pressure reach the set value, and maintain the temperature at a constant pressure. A.3.3 After 24h of the test, stop heating, discharge steam from the pressure relief valve, open the pressure vessel again, and take out the sample. A.3.4 Wash the surface corrosion with an organic solvent. If the corrosion is serious, it should be immersed in an organic solvent and cleaned with ultrasonic waves for 3min~5min, and then dried thoroughly.
A.3.5 Weigh it, the accuracy is 0.001g.
A.4 Expression of analysis results
Weight loss rate is calculated as follows:
Wherein:
R(%) = mo - m:
Weight loss rate, in percentage per square centimeter (%/cm\): mass of the sample before the test, in grams (g); mo-
mass of the sample after the test, in grams (g); m1
S——surface area of ​​the sample before the test, in square centimeters (cm2). o
Appendix B
(Informative Appendix)
Guide to process selection
XB/T903-2002
Sintered iron-boron permanent magnet material is a highly active powder metallurgy material, which is prone to corrosion. Therefore, when surface electroplating is performed on it, appropriate pretreatment and electroplating process should be carefully selected. Before electroplating, sintered NdFeB permanent magnet materials must go through chamfering, degreasing, pickling, ultrasonic cleaning and other processes that can obtain a stabilized and clean surface to obtain a coating with good bonding, low porosity and long-lasting corrosion resistance. When selecting an electroplating process, it is necessary to consider the process's protectiveness and production practicability, and also to pay attention to the impact and degree of damage that electroplating emissions will cause to the environment. The environmental conditions for the use of each electroplating layer are shown in Table B.1. Table B.1 Environmental conditions for the use of each electroplating layer
Coating category
B.1 Chamfering
Post-processing code
Description of environmental conditions for use
Exposure to an indoor atmospheric environment where condensation may occur, and the long-term stability of the appearance and internal performance and a long service life are required.
Used in slightly corrosive conditions, limited corrosion resistance against short-term pollution and discoloration, used in harsh atmospheres, such as organic corrosive atmospheres; in places requiring higher corrosion resistance, exposed to indoor atmospheric environments where condensation may occur, and requiring long-term stability of appearance and internal performance and a longer service life.
Good appearance and weldability, used in places where the surface can be welded and electrical contact. Good appearance and weldability, low contact resistance, poor surface discoloration resistance, used in places where the surface can be welded and electrical contact. Good decorative effect, not easy to discolor the surface, low contact resistance, high cost, used in high-reliability electronic equipment such as electrical contact and high-end decorations.
Small parts can be chamfered with a centrifugal finishing machine, and larger parts can be chamfered with a spiral vibration or centrifugal vortex finishing machine after grinding the edges with a grinding wheel. Chamfering should be carried out in a neutral or slightly alkaline medium, and acidic or corrosive media should not be used for chamfering. B.2 Degreasing
It is advisable to carry out in a neutral or weakly alkaline degreasing agent. To avoid oxidation or hydrogen permeation, it is best not to perform anodic or cathodic electrolytic treatment. B.3 Pickling
Use dilute nitric acid solution or weak organic acid for short-term pickling, but do not pickle in strong halogen acid, and avoid pickling in high-concentration strong acid, otherwise, the material surface will be rapidly coarsened or even powdered. B.4 Ultrasonic cleaning
Ultrasonic cleaning should be carried out after each treatment process to ensure the cleaning effect and prevent contamination of the next process. B.5 Electroplating
Electroplating should use a low-corrosive plating solution, and it is best to use a multi-layer combined coating to meet actual use requirements. If necessary, post-treatment can be performed to further improve corrosion resistance.1 If the appearance and thickness test results of the coating are unqualified, the single product is considered unqualified. Inspection is allowed piece by piece, and the qualified ones are delivered. 9.5.2 If the corrosion resistance and bonding strength test results of the coating are unqualified, double samples are taken from the batch of products for re-inspection of the unqualified items. If one result is still unqualified, the batch of products is unqualified. 10 Marking, packaging, transportation, storage
10.1 Marking
The electroplated products that have passed the inspection should have labels with the following content: a) Supplier name and address:
b) Sales
Supplier quality inspection department stamp:
c) Supplier inspection date.
10.2 Packaging
Electroplated products should be packaged with clean soft materials and properly stored. The packaging material should not affect the performance of the coating. 10.3 Transportation and storage
The packaged products should be stored in a dry and corrosive environment, away from moisture and heat sources, and avoid direct exposure to sunlight. Handle with care during transportation.
4 Quality certificate
Each batch of products should be accompanied by a quality certificate, indicating: a)
Name of supplier;
Product name;
Batch number, number of pieces;
Results of various analysis and inspections and stamps of the technical supervision department; Number of this standard;
Inspection date;
Date of shipment.
XB/T903--2002
XB/T903—2002
A.1 Sample preparation
Appendix A
(Informative Appendix)
Accelerated weight loss test
Process the NdFeB workpiece into a sample of $10mm×10mm, and measure its size with an accuracy of 0.01mm. A.2 Test conditions
A.2.1 The steam pressure in the pressure vessel is 0.20MPa～0.24MPa, and the temperature is 120C±3C. A.2.2 Distilled water or deionized water with a pH of 6.7～pH7.2 is used as vaporized water in the pressure vessel. A.3 Steps
A.3.1 Wash the sample with an organic solvent (such as gasoline), and weigh it after drying. Accurate to 0.001g. A.3.2 Place it in a pressure vessel, raise the temperature to the set pressure, and maintain the temperature at a constant pressure. A.3.3 After 24 hours of testing, stop heating, discharge steam from the pressure relief valve, open the pressure vessel again, and take out the sample. A.3.4 Use an organic solvent to clean the surface corrosion. If the corrosion is serious, soak it in an organic solvent and use ultrasonic cleaning for 3min~5min, then dry it thoroughly.
A.3.5 Weigh it to an accuracy of 0.001g.
A.4 Expression of analysis results
Weight loss rate is calculated as follows:
Where:
R(%) = mo - m:
Weight loss rate, in percentage per square centimeter (%/cm\): mass of the sample before the test, in grams (g); mo-
mass of the sample after the test, in grams (g); m1
S——surface area of ​​the sample before the test, in square centimeters (cm2). o
Appendix B
(Informative Appendix)
Process Selection Guide
XB/T903-2002
Sintered NdFeB permanent magnet material is a highly active powder metallurgy material that is prone to corrosion. Therefore, when electroplating its surface, the appropriate pretreatment and electroplating process should be carefully selected. Before electroplating, sintered NdFeB permanent magnet material must undergo chamfering, degreasing, pickling, ultrasonic cleaning and other processes that can stabilize and clean the surface to obtain a coating with good bonding, low porosity and long-lasting corrosion resistance. When selecting an electroplating process, it is necessary to consider the process's protectiveness and production practicability, and also to pay attention to the impact and degree of damage that electroplating emissions will cause to the environment. The environmental conditions for the use of each electroplating layer are shown in Table B.1. Table B.1 Environmental conditions for use of each electroplating layer
Coating category
B.1 Chamfer
Post-treatment code
Description of environmental conditions for use
Exposure to indoor atmospheric environment where condensation may occur, and the appearance and internal performance must be long-term stable and the service life must be long.
Used in slightly corrosive conditions, limited corrosion resistance against short-term pollution and discoloration, used in harsher atmospheres, such as organic corrosive atmospheres; where higher corrosion resistance is required, exposed to indoor atmospheric environment where condensation may occur, and the appearance and internal performance must be long-term stable and the service life must be long.
Good appearance and weldability, used in surface weldable and electrical contact situations. Good appearance and weldability, low contact resistance, poor surface resistance to discoloration, used in surface weldable and electrical contact situations. Good decorative properties, not easy to discolor the surface, low contact resistance, high cost, used in high-reliability electronic equipment such as electrical contact and high-end decorations.
Small parts can be chamfered with a centrifugal finishing machine, while larger parts can be chamfered with a spiral vibration or centrifugal vortex finishing machine after grinding the edges with a grinding wheel. Chamfering should be carried out in a neutral or slightly alkaline medium, and acidic or corrosive media should not be used for chamfering. B.2 Degreasing
It is best to use a neutral or weakly alkaline degreasing agent. To avoid oxidation or hydrogen permeation, it is best not to perform anodic or cathodic electrolytic treatment. B.3 Pickling
Use dilute nitric acid solution or weak organic acid for short-term pickling, but do not pickle in strong halogen acid. Do not pickle in high-concentration strong acid, otherwise the material surface will be rapidly coarsened or even powdered. B.4 Ultrasonic cleaning
Ultrasonic cleaning should be carried out after each treatment process to ensure the cleaning effect and prevent contamination of the next process. B.5 Electroplating
Electroplating should use a low-corrosive plating solution, and it is best to use a multi-layer combined plating layer to meet actual usage requirements. If necessary, post-treatment can be performed to further improve corrosion resistance.1 If the appearance and thickness test results of the coating are unqualified, the single product is considered unqualified. Inspection is allowed piece by piece, and the qualified ones are delivered. 9.5.2 If the corrosion resistance and bonding strength test results of the coating are unqualified, double samples are taken from the batch of products for re-inspection of the unqualified items. If one result is still unqualified, the batch of products is unqualified. 10 Marking, packaging, transportation, storage
10.1 Marking
The electroplated products that have passed the inspection should have labels with the following content: a) Supplier name and address:
b) Sales
Supplier quality inspection department stamp:
c) Supplier inspection date.
10.2 Packaging
Electroplated products should be packaged with clean soft materials and properly stored. The packaging material should not affect the performance of the coating. 10.3 Transportation and storage
The packaged products should be stored in a dry and corrosive environment, away from moisture and heat sources, and avoid direct exposure to sunlight. Handle with care during transportation.
4 Quality certificate
Each batch of products should be accompanied by a quality certificate, indicating: a)
Name of supplier;
Product name;
Batch number, number of pieces;
Results of various analysis and inspections and stamps o
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