Some standard content:
GB/T 9798—1997
This standard is a revision of GB9798-88 based on ISO1458:1988 Metallic coatings—Nickel electrodeposited coatings. It is equivalent to the ISO standard in terms of technical content and its writing rules are in accordance with GB/T1.1-1993. The original standard GB9798-88 Metallic coatings—Nickel electrodeposited coatings was formulated with reference to ISO1458:1974 Metallic coatings—Nickel electrodeposited coatings. 1458:1988 Metallic coatings—Nickel electrodeposited coatings is a revised version of ISO1458:1974. This standard replaces the original GB9798-88 Metallic coatings—Nickel electrodeposited coatings from the date of its promulgation and implementation. Appendices A, B, C, and DE of this standard are appendices to the standard. Appendix F of this standard is a suggestive appendix.
This standard was proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the Standardization Technical Committee for Metal and Non-metal Coatings of China. The responsible drafting unit of this standard is the Wuhan Materials Protection Research Institute of the Ministry of Machinery Industry. Participating drafting units of this standard include: Shanghai Yongsheng Additive Factory, Technology Research Institute of the Ministry of Electronics, and Hubei Import and Export Commodity Inspection Bureau. The main drafters of this standard include: Yang Mingan, He Shaoxin, Shen Pinhua, Yu Donglin, Li Yingming, and Mao Zuguo. This standard was first published in September 1988.
GB/T97981997
ISO formerly
ISO (International Organization for Standardization) is a worldwide union of national standards bodies (ISO member bodies). The work of formulating international standards is generally carried out by ISO technical committees. If each member body is interested in a topic determined by a technical committee, it has the right to make a statement to the committee. Governments and non-governmental international organizations that have contact with ISO may also participate in the work. In all aspects of electronic standardization, ISO works closely with the International Electrotechnical Commission (IEC).
Draft international standards approved by the technical committee are sent to the member bodies for approval before being adopted as international standards by the ISO Council. According to ISO procedures, at least 75% of the member bodies participating in the voting must approve it before it is considered to be adopted. International Standard ISO1458 was developed by ISU/TC107 Technical Committee on Metallic and Other Inorganic Coatings. This second edition replaces and cancels the first edition (ISO1458:1974) and is a revision of International Standard ISO1458:1974. Users should note that all international standards are subject to revision. Therefore, unless otherwise specified, other international standards referenced in this standard are in their latest versions.
1 Scope
National Standard of the People's Republic of China
Metallic Coatings
Nickel Electrodeposited Coatings
Metallic coatings - Electrodeposited coatings af nickelCB/T 9798:1997
eqv ISO 1458:1988
Generates GB 9798--88
This standard specifies the requirements for decorative and protective nickel electrodeposited coatings on steel, zinc alloy, copper and copper alloy, lead and aluminum alloy. Several levels of coatings with different thicknesses and a guide for selecting the coating level of the plated parts exposed to the corresponding service conditions are given. This standard is applicable to decorative and anti-expansion nickel electrodeposited coatings on iron, zinc alloy, copper and copper alloy, aluminum and aluminum alloy. The pure nickel plating without chrome surface layer specified in this standard is applicable to key parts that can prevent the plating from discoloring due to friction or contact during use, and is also applicable to forgings that use non-chrome surface layers to prevent discoloration or have low requirements for discoloration. Note: Similar plating layers used for decorative protection and not discoloring during use can be found in GB/T S797, and chrome electrodeposition layers for engineering use can be found in GB 12332. This standard does not specify the required surface state of the base metal before electroplating. This standard is not applicable to plating on plates, strips, wires that are not formed by hand, nor is it applicable to inlays on threaded fasteners or closed-coil springs.
2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T4955-1997 Metal coating thickness measurement anodic dissolution coulometric method (el[VISO2177:1972) GB5270-85 Metal coating (electrodeposition layer and chemical deposition layer) on metal substrate Adhesion strength test method (cgv IS0 2819: 1980)
GF6462-86 Microscopic measurement of cross-sectional thickness of metal and oxide coatings (eqVISU1463: 1982) GB/T9797-1997 Electrodeposition of nickel + chromium and copper + nickel + chromium metal coatings (eqIS01456: 1988) GB1233290 Nickel bonding layer for metal coatings (cqV1SO4526: 1985) G312334-90 Definition and general rules for thickness measurement of metal and other mechanical coatings (cqVISO2064: 1980) Electrodeposited metal coatings Sampling inspection procedure for counting of finishing (IS(4519:1980) GB12609-90
GB/T18744-U2 Measurement of thickness of nickel electroplated layers on magnetic and non-magnetic substrates (idtIS2361.1982) GB/T16921-1997 X-ray spectrometric method for measurement of thickness of metallic coatings (cqV1SO3497:1990) GB/T10125-1997 Artificial atmosphere corrosion test with fog test (evISO9227:1990) 3 Definitions
This standard adopts the definition of GB12334.
4 Information to be provided by the purchaser to the electroplater
4.1 Necessary information
Approved by the State Administration of Technical Supervision on June 27, 1997, and implemented on January 1, 1998
GB/T 9798—1997
When ordering plated parts that meet this standard, the purchaser should ask the electroplater to provide the following information. 4.1.1 Number of this standard,
4.1.2 Number of service conditions of the base metal and the severity of the service environment of the plated parts (see 5.1). 4.1.3 Surface finishing requirements + such as bright, dark or satin (see 7.2), which can also be provided by the purchaser, or samples that indicate the surface finishing requirements or surface finishing range can be requested by the purchaser. 4.1.4 The main surfaces should be marked on the part drawing or a sample station with appropriate markings should be provided. 4.1.5 Type of corrosion test to be used (see 7.4). 4.1.6 Type of bond strength test to be used (see 7.3). 4.1. Extent of permissible defects on major surfaces (see 7.1) 4.1.8 Location of unavoidable hanger marks or contact marks on major surfaces (see 7.1) 4.1.9 Sampling method and acceptance criteria (see Chapter 8). 4.2 Additional information
The purchaser may also provide the following additional information.
4.2.1 Tensile strength of steel parts and heat treatment requirements before and/or after electroplating (Chapter 6). 4.2.2 Cannot be 20 mm in diameter. mm ball contact surface thickness requirement (see 7.2.1). 4.2.3 Is copper plating required (see 5.2b) 1.5 Grading
5.1 Service condition number
The service condition number is used by the purchaser to specify the severity of the service environment of the plated parts. The number is as follows: 3 Severe 2 - Moderate 1 Mild 0 - Very Mild
The typical service conditions corresponding to various service condition numbers are shown in Appendix F (Appendix). 5.2 Coating grading number
The coating grading number is composed in the following order:
a) The chemical symbol of the base metal (or the main metal in the alloy matrix), followed by a slash, as follows: F/——Indicates that the base metal is steel; Zn/-. Indicates that the base metal is steel; Zn/-. Indicates that the base metal is steel. b) When copper or copper alloy with copper content exceeding 50% is used as the base coating, the chemical symbol represents copper or copper alloy layer; c) The number after Cu represents the minimum local thickness of the copper coating, in um; e) The chemical symbol for nickel is Nit
e) The number after Ni represents the minimum local thickness of the coating, in um; f) The symbol for the type of nickel coating (see 7.2.3.2). For example, the complete coating classification number is:
Fe/Cu20 Ni30b
Note: Unless otherwise specified by the purchaser, the minimum thickness requirement for the nickel coating is only applicable to the surface portion that can be contacted by a ball with a diameter of mm (see 7.2.1). 5.3 Plating corresponding to each service condition number The plating grade number corresponding to each service condition number of various base metals is shown in Tables 1 to 4. 6
Service condition number
GB/T 9798—1997
Nickel electroplating on steel (or iron)
Plating grade number
Fe/Ni3ob
Fe/Ni20b
Fe/NiIob
Fe/Nisb
When the service condition is 3.2.1, nickel can replace h nickel in any grade number, or d nickel can replace b nickel. Steel base layer can be used. If the minimum thickness of the copper base layer is 20um, the minimum thickness of the nickel can be reduced by 5um when the service condition is 3, which is lower than the value listed in the table. The minimum thickness of the plating layer cannot be reduced when the service conditions are 0, 1 and 2 and the copper base layer is used. Table 2 Nickel electroplating on zinc alloy
Service condition number
Coating grade number
Zn/Cu Ni25h
Zn/Cu Ni15b
Zn/Cu Ni1oh
Zn/Cu Ni5h
When the service conditions are 3, 2, and 1, nickel can replace nickel b in any grade number, and P or D nickel can replace nickel 6. If the minimum thickness of copper is increased to 15μm, the minimum thickness of the plating can be reduced by 5μm and lower than the value of the table agent when the service condition number is 9. For other service conditions under 2
, the minimum thickness of the plating shall not be reduced when the coating thickness is increased. Table 3 Nickel electroplating layer on copper and copper alloy
Service condition number
Plating grade number
Cu/Ni20b
Cu/Ni10
Cu/Nisb
Cu/Ni3b
Note, when the service conditions are 3, 2, s can replace b, β or d in any service condition. Nickel can replace h. Table 4 Nickel electroplating layer on aluminium and aluminium alloy
Service condition number
Note: 5, 3 or 4 can replace h in any service condition. Heat treatment of steel parts
Inlay grade
Al/Ni3ob
Al/Ni2b
Fe/Niloh
If the purchaser specifies that heat treatment is required before and/or after plating (see 4.2.1), the heat treatment shall be carried out in accordance with the recommended specifications in Appendix A (Standard Appendix).
7 Requirements for coating
7.1 Appearance
GB/T 9798
There shall be no obvious coating defects on the main surface of the plated parts, such as: bubbles, pores, roughness, cracks, local non-plating areas, spots or discoloration. The degree of allowable coating defects on non-main surfaces and the location of inevitable hanger marks on the main surface shall be specified by the purchaser. 7.2 Thickness and type of coating
7.2.1 General provisions
The thickness and type of coating corresponding to the specified service condition number shall be consistent with the classification number in Tables 1 to 4. The minimum thickness requirement of the surface metal coating that can be contacted by a ball with a true diameter of 20 mm shall be specified. The purchaser may also specify the thickness requirements that other surfaces should meet. The method for measuring the coating thickness is shown in 9.1.7.2.2 Thickness of coating
The minimum thickness of copper coating in copper-nickel coating is shown in the notes to Tables 1 to 4. Note: All nickel layers specified in Table 3 are plated on a bottom point with a thickness of at least 8 ut1 (5.2L)]. In order to obtain sufficient coating on the low current area of non-main surfaces of complex-shaped parts, the minimum coating thickness on the main surface may be increased to 1G to 12 μm. 7.2.3 Thickness and type of nickel coating
7.2.3.1 Thickness of nickel coating
The total minimum thickness of the nickel coating shall comply with the coating grade number (see 5.2). 7.2.3.2 Type of nickel coating
Types of nickel coating shall be indicated by the following symbols:
h---full bright nickel deposition,
mechanically polished dark nickel or semi-bright nickel:
--dark nickel, satin nickel or semi-bright nickel without mechanical polishing:
d--effect nickel or blue nickel. For relevant requirements, see Table 5. Table 5 Requirements for double or two-layer nickel layer
Second layer (nickel layer type)
Bottom (s)
Intermediate layer (commercial sulfur) (b)
Straight layer (b)
Secondary elongation "
1) The test method for elongation is shown in Appendix B (Appendix to the standard). Yu"
Atm/r)
+0. 04 and 0. 15
Thickness as a percentage of the total image layer thickness
2) The sulfur content of the nickel layer is specified to indicate the type of bonding liquid used. There is no simple test method for the sulfur content of the plated layer, but according to the requirements of the Appendix (Appendix) of the standard, the use of specially prepared samples can be used to determine the adhesion. 3) According to the provisions of B 6462, prepare the cross-section of the bond layer, polish and diffusely etch, and use a microscope to measure and identify the thickness ratio and type of the multi-layer nickel: 7.3 Bonding strength
The bonded layer and the H body and each group of layers should be well bonded and can pass the corresponding tests specified in 9.2. 7.4 Corrosion resistance
The bonded layer should be free of pores. The corrosion resistance of the coating under certain service conditions should pass the corresponding tests in 9.3 and be rated according to Appendix C (Appendix to the standard), with the lowest rating of 9. 8 Sampling
The sampling procedure of B12609 is selected, and the acceptance level should be specified by the purchaser. 9 Test methods
9.1 Thickness
GB/T9798--1997
The thickness of the coating and the thickness of each combined layer should be measured at any part of the surface that can be touched by a ball with a diameter of 20mm. The coulometric method specified in GB/T4955 can measure the total thickness of the nickel layer, the thickness of the creeping layer and the thickness of the copper alloy base layer of known composition. The microscopic method specified in GB6462 can be used to measure the thickness of each nickel layer with a minimum thickness of 10μm. The thickness of the copper or copper alloy base layer can also be measured (see 7.2).
Note: The STEP test method can also be used to determine the layer thickness of double and triple nickel coatings and the chemical relationship between the layers. Since the STEP method test can be used for production parts, it has been widely used and has become a part of some company and national standards. There is still controversy about the optimal value of the potential difference between the layers to ensure good protective performance of bright sickle and semi-bright nickel, but some companies have set this potential difference to not less than 125mV. GB/T 150-1458, which is gradually adopted by this standard, has decided to specify this test method in its future revision, but no document of the STEP method that can be accepted by this international standard has been proposed so far. It is recommended that users of this standard are familiar with this test and use it well, which will significantly improve the quality of electroplated products. If properly calibrated, the magnetic method specified in GB/T 1344 can measure the total thickness of b, d, and p nickel electroplating layers on zinc alloys, copper alloys and steel with known composition. Other thickness measurement methods that have been proven to have a measurement error within 10% can also be used. In case of dispute, the thickness of nickel layers less than 10μm is measured by the warehouse method; the thickness of nickel layers greater than 10um is measured by the microscope method.
9.2 Bonding strength
The test is carried out according to the thermal test or chain knife test method specified in GB527). After the test, the coating should not be separated from the substrate, and there should be no separation between the coatings.
9.3 Corrosion resistance
Pure nickel coatings without a chrome layer have not been widely used, so that there is limited information on accelerated corrosion tests and actual use. The plated parts shall be subjected to a corrosion test specified in Appendix E (standardized appendix) according to a certain service condition. Any special corrosion test to be used shall be specified by the customer. There is no experiment to determine the duration of each corrosion test. A guide for selecting the test duration is provided in Appendix E. In order to ensure the effective application of the coating, the customer shall determine the duration of the corrosion test according to the use of the coating. The several corrosion tests specified in GB/T10125 provide a set of means to control the continuity and quality of the coating. However, the correlation between the test duration and the service life of the plated parts is small. After a certain corrosion test, the test pieces shall be inspected and evaluated according to the provisions of Appendix B (see 7.4). 9.4 Elongation
When tested according to the method specified in Appendix B, the elongation of the nickel layer shall not be less than 7.2.3.2. Category
GB/T 9798-1997
Appendix A
(Standard Appendix)
Recommended heat treatment specifications for steel parts
In order to reduce the risk of damage caused by chlorine embrittlement, certain steel parts should be heat treated. Heat treatment includes the following two categories: a) Stress relief before electroplating:
b) Heat treatment after electroplating.
Recommended heat treatment specifications are shown in Table A1. Table A1 Recommended heat treatment specifications for steel parts General requirements Special restrictions on heat treatment Steel parts that have been cold-worked and hardened before electroplating: Steel parts with a tensile strength greater than or equal to 1 000 MPa (and equivalent hardness); Steel parts that have been machined or ground after tempering, heat treatment at the lowest possible temperature for 30 min within a temperature range of 5% below the lower tempering temperature, or heat treatment within the temperature range of 190°C to 210°C for 1 min h
Steel parts that have been carburized, box-hardened or induction-hardened should be heat-treated at a lower temperature for a longer period of time, such as at 170℃
for more than 1h
after electroplating
Steel parts that have been cold-work hardened+Tensile strength greater than or equal to 100 MPa (or with a hardness of 1\); parts serving under fatigue stress or continuous load conditionsTensile strength of 1000 and 1150
1150 and 1480
Maximum thickness of work
12~-25
12--25
Minimum time of heat treatment at a temperature of 190℃～210℃
Note: Heat treatment should be carried out within the key period of
16 h
If the workpiece has been surface hardened, the heat treatment should be carried out at a lower temperature for a longer time. However, it should be proved that these process conditions are effective for the workpiece and accepted by the purchaser. 1) The hardness value corresponding to 10(0MPa is approximately: 30HRC295HV.280HB Appendix B
[Standard Appendix]
Ductility test
B1 Scope
This annex specifies the method for measuring the elongation of the coating on the electroplated test piece and provides a means to evaluate the ductility of the coating. Note: This method is used to check whether the type of nickel plating meets the requirements of .2.3.2, and can be used to evaluate the ductility requirements of other coatings (see 9.1). B2 Principle
Under specified conditions, the electroplated test piece is bent around a circular axis, and the surface of the test piece is tested and its elongation is calculated. B3 Device | |tt||Round shaft, diameter 11.5mm±0.1mm.
B4 Procedure
B4.1 Test piece preparation
CB/T9798-1997
Prepare a 150mm long, 10mm wide, 1.0mm±0.1mm electroplated test piece as follows. Polish a plate similar to the substrate of the electroplated workpiece. If the substrate is a zinc alloy, soft brass can be used instead. The plate used must be large enough so that when the test piece is cut from the plate, the remaining peripheral width must not be less than 25mm. Electroplate nickel on the polished surface of the plate with a coating thickness of 25μ. The plating solution and electroplating specifications used should be the same as those for the plated workpiece. Cut from the electroplated sheet with a shearing machine or scissors. Test piece, carefully file or grind its edges round. At least the side with coating should be chamfered.
B4.2 Test
Bend the test piece (see B4.1) 180° along the surface of the circular axis (see B3) until the two ends of the test piece are parallel to each other. During the bending process, the electric key surface is subjected to tension. The applied pressure should be stable. The test piece and the circular axis should be in contact. After bending, cracks on the convex surface of the bent test piece should be checked. B5 Result Indication
After the test, when there are no cracks penetrating the convex surface (see note) on the specimen, it can be considered that the tested coating meets the minimum requirement of elongation of 8. Note: Small cracks in the nickel coating on the edge of the specimen does not mean that the elongation of the coating is unqualified. Appendix C
(Appendix to the standard)||t t||Metallic coatings non-anodic to base metal - Accelerated corrosion test - Method for evaluation of results Note: This annex is equivalent to 1S01162:19734 Metallic coatings - Accelerated corrosion test of non-anodic coatings on base metal - Method for evaluation of results".
c1 Scope
This annex gives a method for determining the performance level of coatings non-anodic to base metal subjected to accelerated corrosion tests. This method only considers the corrosion of the base metal. This method is only applicable to test pieces that have been simply inspected and not scrapped according to the size or classification of each corrosion defect required by the national standard for the specific coating.
This method is not applicable to the evaluation of single pieces with a main surface less than 25 mm. C2 Definitions
This annex adopts the following definitions.
C2.1 The surface of the workpiece that has been plated or is to be plated plays a major role in appearance and (or) service performance. The main surface can be agreed upon as required and marked on the design drawing, or a sample with appropriate markings can be provided. C2.2 Corrosion pits A surface pick-up defect where the cover layer has been penetrated and corrosion products of the base metal or peeling of the cover layer are clearly visible.
Discoloration or other surface defects that do not penetrate the cover layer are not counted as corrosion pits. The area of the small finger of the corrosion pit that penetrates the cover layer is not counted as the related rusted part. C3 Sampling
CB/T 9798—1997
The batch shall be sampled according to the specified method, and the total main surface area of the sample shall exceed 5000mm2. If the main surface area of the individual pieces constituting the sample is less than 5000mm2, the evaluation sample shall be composed of a sufficient number of individual pieces so that its total main surface area is equal to or greater than 5000mm2. If the selected evaluation level is 1 or greater than 8, the total main loss area of the sample shall exceed 10000mm2. C4 Inspection of the sample after the test
The sample shall be inspected immediately after the corrosion test is completed. If it is necessary to remove the residual corrosive medium, it should be rinsed in running water before inspection.
The corrosion products can then be removed in order to assess the size of the corrosion points. In order to make the evaluation and obtain the most accurate rating results, a transparent and soft plastic film measuring plate with 5mm×mm grids is covered on the main surface of the coating to be tested. The main surface of the coating is divided into several squares with a side length of 5mm. Count the total number of squares with a side length of 5mm on the main surface of the sample, N, and count the number of such squares with one or more corrosion points. When evaluating the total area of the sample, the squares occupied by the sample for more than half should be counted as squares, and those less than half should not be counted. If the corrosion point occupies more than one square, it should only be counted once during the evaluation, but for cracks that cross more than one square, each square that the crack enters should be counted. C5 Evaluation level
The frequency of corrosion spots is determined as a percentage by the following formula: Corrosion spot rate = n/N × 100%
Evaluate the level of the sample according to the following table C1
Rate (%)
(No corrosion spots)
2-0. 25~ C. 5
1 -- 2
16-~32
2>32~64
*) See ca.
(Appendix to the standard)bzxz.net
Determination of sulfur content in nickel electrodeposition layer
Evaluation level
Note: There is an instrument that uses infrared detection method to measure sulfur dioxide produced by combustion. The instrument is equipped with a computer device that can directly read the sulfur content. DDOverview
GB/T 9798—1997
This appendix specifies two methods for measuring sulfur content to detect whether various nickel electrodeposits comply with the requirements of 7.2.3.2. Alternative methods or improved methods may generally be adopted upon agreement between the supplier and the buyer. D1 Combustion-iodate titration method
D1.1 Scope
This part of this appendix specifies the combustion-titration method for measuring sulfur content in nickel electrodeposits. It is applicable to products whose sulfur content in nickel electrodeposits, expressed as sulfur, is within the range of 0.005% (m/m) to 0.5% (m/m). D1.2 Principle
The test piece is burned in the oxygen flow of the induction furnace, and the sulfur dioxide gas released during combustion is absorbed by acidified potassium iodate starch solution, and then titrated with potassium iodate solution. This potassium iodate solution should be freshly calibrated with a steel standard sample with a certain amount of sulfur dioxide, so that the error caused by the instrument and the error caused by the change of sulfur monoxide absorption over time can be corrected. A blank test should be carried out to eliminate the influence of factors such as argon and flux. D1.3 Interference
Generally, other elements in nickel electrodeposition have no interference with the test. D1.4 Reagents
During the analysis process,Only analytical grade reagents and distilled water or water of equivalent purity shall be used. D1.4.1 Hydrochloric acid solution (3+97)
Mix 3 volumes of hydrochloric acid (density p = 1.19 g/mL) with 97 volumes of water. D1.4.2 Iron chips (low sulfur) flux.
D1.4.3 Iron powder (low sulfur) flux.
D1.4.4 Potassium iodate standard solution A (equivalent to 0.10 mg/mL sulfur). Dissolve 0.2225 g potassium iodate (K10.) in 900 mL of water in a 1000 mL volumetric flask, then dilute to 400 °C and mix well.
D1.4.5 Potassium iodate standard solution B (equivalent to 0.02 mg/mL sulfur) Transfer 200 mL of potassium iodate standard solution A (see ID1, 4.4) to a 1000 mL single-scale volumetric flask, dilute to the mark and mix well. Note: The sulfur equivalent assumes that the sulfur is completely converted to sulfur monoxide. However, the sulfur recovered as sulfur dioxide may be less than 100%. If the temperature and oxygen flow rate in the induction furnace are kept constant, the recovery rate will be constant. Therefore, the standard test must be analyzed to determine an analytical coefficient. D1.4.6 Starch-iodide bath
Put 1 iodide starch in a small beaker and add 2 mL of water. Stir to form a uniform paste, pour into 50 mL of boiling water, cool, add 1.5 g of potassium iodide (KI), stir until dissolved, dilute to 100 ml and probe. D1.4.7 Granular tin (low sulfur) flux
D1.4.8 Pure oxygen.
D1. 5 Standard sample
Should be a standard steel with corresponding sulfur content and verified. D1.6 Instrument and device
General laboratory device.
D1.6.1 Induction heating device, consisting of the following main parts: 9) Oxygen purification tube is used to remove any impurities remaining in oxygen (see 14.8), and is connected to the valve b) Valve is used to control the flow rate of oxygen flowing through the heating tube, connected to the heating tube: c) Heating tube, fixed in the induction furnace, and connected to the sulfur dioxide receiver: d) The sulfur dioxide receiver is filled with absorption liquid using a burette; e) Induction furnace.
GB/T 9798-1997
Note: When operating the induction furnace, appropriate safety measures should be taken. D1.6.2 Snail, covered. Used to hold the sample.
D1.7 Procedure
D1.7. 1 Preparation of Nickel Foil for Test
D1.7.1.1 Preparation - Cold rolled steel sheet of suitable size, e.g. 150 mm long, 100 mm wide, 1 mm thick. Degrease the test piece, pickle it, and electroplate it with a nickel layer of about 7.5 μm thick and well bonded. Polished nickel sheet or polished stainless steel sheet may be used instead of electroplated nickel steel sheet. D1.7.1.2 Passivate the test piece anodically in an alkaline cleaning agent solution at 3 V for 5 to 10 s at a temperature of 70 to 80 °C containing 30 g/L NaOH, 30 g/L NaPO, or 60 g/L of any other suitable alkaline cleaning agent for the anodizing. D1.7.1.3 Using the same solution and plating specifications as the workpiece to be plated, plate a 2537 μm nickel layer on the passivated test piece F to ensure that the test piece is representative of the plated workpiece.
D1.7.1.4 Use hand shears or mechanical shears or any other method to remove the edges of the test piece to make it easy to peel off the test nickel foil. D1.7.1.5 Peel off the test foil from the test piece, wash off the electrolyte with water, and then wipe it dry, for example, with filter paper. Use scissors to cut the test nickel foil into squares with a side length of 2~3mm, put it in a 100ml beaker, add water to cover it, and heat it to boiling. Pour out the water and wash the test nickel foil with methanol. Then pour it on the filter paper and dry it naturally in the air. D1.7.2 Sample quantity and standard quantity
According to the estimation of the sulfur content of the coating on the plated workpiece, weigh a certain amount of sample and standard sample respectively, accurate to 0.0001g. The weighing amounts of nickel foil (see D1.7.1) and standard sample (see D1.7.3) for the test are as specified in Table D1. Table D1 "Mass of test specimens and standard samples
Estimated sulfur content of plated parts
y(m/m)
0. 05-0. 10
0.10~0.50
D1.7.3 Calibration
Mass of the corresponding test specimens or standard samples to be weighed g
0.20±0.02
Choose at least two standard samples, whose sulfur contents are close to the upper and lower limits of the estimated sulfur content of the test specimens, respectively. In addition, select a standard sample whose sulfur content is close to the average value of the upper and lower limits. The average value standard sample can also be prepared by mixing the other two standard samples. Then accurately weigh each standard sample according to the requirements of D1.7.4 and determine its sulfur content. n1.7.4 Measurement
D1. 7. 4. 1 Add 1 g of iron filings flux (see D1. 4. 2), 0. 8 g iron powder flux (see D1.4.3), 0.9 g tin flux (see D1.1.7) in a crucible (see D1.6.2), add the sample (see D1.7.2), and cover the crucible. D17.4.2 Install the heating device (see D1.6.1), turn on the induction furnace switch, and heat it to the working temperature. Pass the oxygen flow (see D1.4.8) through the heating device (see Note 1) at a flow rate of 500ml./min, and inject the hydrochloric acid solution (see D1.4.1) into the sulfur dioxide receiver to the predetermined scale (see Note 2). Add 2mL of starch-iodide solution (see D1.4.6) and continue to pass the oxygen flow. Add the corresponding potassium iodate solution (see T1.4.4 or D1.4.5) from the burette, and the end point is when the white turns light blue, and then fill the burette again. 1 The oxygen flow rate can be adjusted according to the operating requirements and instrument requirements, but the oxygen flow rate for the sample and standard measurement should be the same. 2 The liquid in the burette should be filled to the same scale: D1. 7.4.3 When the operating temperature of the induction furnace is maintained for at least 15 seconds, place the covered crucible containing the sample and the olefination promoter on the bracket of the induction furnace. When the oxygen flow rate is adjusted to 1000~1500mL/min, raise the burette, close the furnace door, and turn on the power. Heat the sample for 8~10 minutes. Titrate continuously with an appropriate potassium iodate standard solution, control the flow rate of the titration solution, and keep the blue color of the solution as much as possible in the initial blue state. This blue color can be maintained for more than 1 minute. The end point is reached. Note the final reading of the burette and open the stopcock to drain the solution in the sulfur dioxide receiver.
n1.8 Blank test1.1 Preparation - Cold rolled steel sheet of suitable size, e.g. 150 mm long, 100 mm wide, 1 mm thick. Degrease the test piece, pickle it, and electroplate it with a nickel layer of about 7.5 μm thick and well bonded. Polished nickel plate or polished stainless steel plate may be used instead of electroplated nickel steel plate. D1.7.1.2 Anodic passivate the test piece in an alkaline cleaning agent solution at 3 V for 5 to 10 s at a temperature of 70 to 80 °C containing 30 g/L NaOH, 30 g/L NaPO, or 60 g/L of any other appropriate alkaline anodic cleaning agent. D1.7.1.3 Electroplate a 2537 μm nickel layer on the passivated test piece F using the same solution and plating specifications as the workpiece to be plated to ensure that the test piece is representative of the plated workpiece.
D1.7.1.4 Remove the edges of the test piece by hand or mechanical shears or any other method to make it easy to peel off the test nickel foil. D1.7.1.5 Peel off the test foil from the test piece, wash off the electrolyte with water, and then wipe it dry, for example, with filter paper. Use scissors to cut the test nickel foil into squares with a side length of 2~3mm, put it in a 100ml beaker, add water to cover it, and heat it to boiling. Pour out the water and wash the test nickel foil with methanol. Then pour it on the filter paper and dry it naturally in the atmosphere. D1.7.2 Sample quantity and standard quantity
According to the estimation of the sulfur content of the coating on the plated piece, weigh a certain amount of sample and standard sample, accurate to 0.0001g. The weighing amount of test nickel foil (see D1.7.1) and standard sample (see D1.7.3) is specified in Table D1. Table D1 "Mass of test specimens and standard samples
Estimated sulfur content of plated parts
y(m/m)
0. 05-0. 10
0.10~0.50
D1.7.3 Calibration
Mass of the corresponding test specimens or standard samples to be weighed g
0.20±0.02
Choose at least two standard samples, whose sulfur contents are close to the upper and lower limits of the estimated sulfur content of the test specimens, respectively. In addition, select a standard sample whose sulfur content is close to the average value of the upper and lower limits. The average value standard sample can also be prepared by mixing the other two standard samples. Then accurately weigh each standard sample according to the requirements of D1.7.4 and determine its sulfur content. n1.7.4 Measurement
D1. 7. 4. 1 Add 1 g of iron filings flux (see D1. 4. 2), 0. 8 g iron powder flux (see D1.4.3), 0.9 g tin flux (see D1.1.7) in a crucible (see D1.6.2), add the sample (see D1.7.2), and cover the crucible. D17.4.2 Install the heating device (see D1.6.1), turn on the induction furnace switch, and heat it to the working temperature. Pass the oxygen flow (see D1.4.8) through the heating device (see Note 1) at a flow rate of 500ml./min, and inject the hydrochloric acid solution (see D1.4.1) into the sulfur dioxide receiver to the predetermined scale (see Note 2). Add 2mL of starch-iodide solution (see D1.4.6) and continue to pass the oxygen flow. Add the corresponding potassium iodate solution (see T1.4.4 or D1.4.5) from the burette, and the end point is when the white turns light blue, and then fill the burette again. 1 The oxygen flow rate can be adjusted according to the operating requirements and instrument requirements, but the oxygen flow rate for the sample and standard measurement should be the same. 2 The liquid in the burette should be filled to the same scale: D1. 7.4.3 When the operating temperature of the induction furnace is maintained for at least 15 seconds, place the covered crucible containing the sample and the olefination promoter on the bracket of the induction furnace. When the oxygen flow rate is adjusted to 1000~1500mL/min, raise the burette, close the furnace door, and turn on the power. Heat the sample for 8~10 minutes. Titrate continuously with an appropriate potassium iodate standard solution, control the flow rate of the titration solution, and keep the blue color of the solution as much as possible in the initial blue state. This blue color can be maintained for more than 1 minute. The end point is reached. Note the final reading of the burette and open the stopcock to drain the solution in the sulfur dioxide receiver.
n1.8 Blank test1.1 Preparation - Cold rolled steel sheet of suitable size, e.g. 150 mm long, 100 mm wide, 1 mm thick. Degrease the test piece, pickle it, and electroplate it with a nickel layer of about 7.5 μm thick and well bonded. Polished nickel plate or polished stainless steel plate may be used instead of electroplated nickel steel plate. D1.7.1.2 Anodic passivate the test piece in an alkaline cleaning agent solution at 3 V for 5 to 10 s at a temperature of 70 to 80 °C containing 30 g/L NaOH, 30 g/L NaPO, or 60 g/L of any other appropriate alkaline anodic cleaning agent. D1.7.1.3 Electroplate a 2537 μm nickel layer on the passivated test piece F using the same solution and plating specifications as the workpiece to be plated to ensure that the test piece is representative of the plated workpiece.
D1.7.1.4 Remove the edges of the test piece by hand or mechanical shears or any other method to make it easy to peel off the test nickel foil. D1.7.1.5 Peel off the test foil from the test piece, wash off the electrolyte with water, and then wipe it dry, for example, with filter paper. Use scissors to cut the test nickel foil into squares with a side length of 2~3mm, put it in a 100ml beaker, add water to cover it, and heat it to boiling. Pour out the water and wash the test nickel foil with methanol. Then pour it on the filter paper and dry it naturally in the atmosphere. D1.7.2 Sample quantity and standard quantity
According to the estimation of the sulfur content of the coating on the plated piece, weigh a certain amount of sample and standard sample, respectively, accurate to 0.0001g. The weighing amount of test nickel foil (see D1.7.1) and standard sample (see D1.7.3) is specified in Table D1. Table D1 "Mass of test specimens and standard samples
Estimated sulfur content of plated parts
y(m/m)
0. 05-0. 10
0.10~0.50
D1.7.3 Calibration
Mass of the corresponding test specimens or standard samples to be weighed g
0.20±0.02
Choose at least two standard samples, whose sulfur contents are close to the upper and lower limits of the estimated sulfur content of the test specimens, respectively. In addition, select a standard sample whose sulfur content is close to the average value of the upper and lower limits. The average value standard sample can also be prepared by mixing the other two standard samples. Then accurately weigh each standard sample according to the requirements of D1.7.4 and determine its sulfur content. n1.7.4 Measurement
D1. 7. 4. 1 Add 1 g of iron filings flux (see D1. 4. 2), 0. 8 g iron powder flux (see D1.4.3), 0.9 g tin flux (see D1.1.7) in a crucible (see D1.6.2), add the sample (see D1.7.2), and cover the crucible. D17.4.2 Install the heating device (see D1.6.1), turn on the induction furnace switch, and heat it to the working temperature. Pass the oxygen flow (see D1.4.8) through the heating device (see Note 1) at a flow rate of 500ml./min, and inject the hydrochloric acid solution (see D1.4.1) into the sulfur dioxide receiver to the predetermined scale (see Note 2). Add 2mL of starch-iodide solution (see D1.4.6) and continue to pass the oxygen flow. Add the corresponding potassium iodate solution (see T1.4.4 or D1.4.5) from the burette, and the end point is when the white turns light blue, and then fill the burette again. 1 The oxygen flow rate can be adjusted according to the operating requirements and instrument requirements, but the oxygen flow rate for the sample and standard measurement should be the same. 2 The liquid in the burette should be filled to the same scale: D1. 7.4.3 When the operating temperature of the induction furnace is maintained for at least 15 seconds, place the covered crucible containing the sample and the olefination promoter on the bracket of the induction furnace. When the oxygen flow rate is adjusted to 1000~1500mL/min, raise the burette, close the furnace door, and turn on the power. Heat the sample for 8~10 minutes. Titrate continuously with an appropriate potassium iodate standard solution, control the flow rate of the titration solution, and keep the blue color of the solution as much as possible in the initial blue state. This blue color can be maintained for more than 1 minute. The end point is reached. Note the final reading of the burette and open the stopcock to drain the solution in the sulfur dioxide receiver.
n1.8 Blank test
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