Electroless nickel phosphorus plating JIS H 8645
JIS H8645 stipulates electroless nickel-phosphorus plating on effective surfaces applied to iron, steel and non-ferrous metal substrates for the purpose of corrosion resistance and wear resistance.
JIS H 8645
1. 1. Definition
The definitions of the main terms used in this standard are based on JIS H0400 and the following.
a) Effective surface The surface of a part that is or should be coated and whose coating is of primary performance and appearance.
b) Heat treatment Heat treatment performed to adjust the hardness of plating and improve wear resistance and adhesion.
2. Grades and symbols
a) Grades As shown in Table 1, the grades of plating are divided into 7 grades according to the minimum thickness of plating.
b) Symbol The plating symbol is based on JIS H 0404.
3. 3. quality
1. Appearance of plating
The appearance of the plating shall be tested by appearance testing and shall have a smooth surface and shall be free of pits, swelling, peeling, exposure of cracked substrate or base plating, and other harmful defects in use.
2. Chemical composition of plating film
The chemical composition of the plating film is tested by an analytical test. Must comply with Table 2.
3. Plating surface roughness
The surface roughness of the plating is tested by a roughness test, and the value is based on the agreement between the delivery parties.
4. Minimum plating thickness
The minimum plating thickness shall be tested by a thickness test and shall comply with Table 1.
5. Plating hardness
The hardness of the plating is tested by a hardness test, and the Vickers hardness is 500 or more and the Knoop hardness is 450 or more.
Annex 7 shows the heat treatment conditions that can make the Vickers hardness 600 to 1000.
(Remarks: The plating thickness of the sample shall be 50 μm or more.)
6. Plating adhesion
The adhesion of the plating shall be tested by the adhesion test and there shall be no peeling or swelling of the plating.
7. Plating porosity
The porosity of the plating is tested by a porosity test, and its quality is based on the agreement between the delivery parties.
8. Prevention of corrosion of substrate
Corrosion prevention of the substrate is tested by corrosion resistance test, and the quality is based on the agreement between the delivery parties.
9. Corrosion resistance of plating film
The corrosion resistance of the plating film shall be tested by a corrosion resistance test after post-plating treatment, and shall have a rating number of 9 or more specified in JIS H8502. Subsequent processing, test time and appearance changes are subject to agreement between the parties to the delivery.
(Remarks may be evaluated by the corrosion weight loss method specified in JIS H8502, if necessary)
10. Abrasion resistance of plating
The wear resistance of the plating is tested by the wear resistance test, and the evaluation method is based on the agreement between the delivery parties.
(Remarks: The plating thickness of the sample shall be 20 μm or more)
11. Plating solder wettability
The solder wettability of the plating is tested by a solder wettability test, the soaked part is uniformly wet, and the surface of the solder should be flat and free of bumps.
(Remarks: After the solder wettability test, perform a bending test in the adhesion test, and the solder must not be scaly or peeled off.)
Table 1 Grade and minimum plating thickness
Table 2 Chemical composition of plating film
4. Base material
The condition of the substrate before plating has a significant effect on the quality of the plating. In particular, when the base material is supplied by the ordering party, the ordering party must show information about the base material in the processing specifications and the like.
(Remarks, the processor visually inspects defects on the surface of the substrate that are harmful to the final finish. For defects, pay attention to the ordering party before processing.)
5. Shot peening process
If shot peening is specified for the purpose of improving fatigue strength, the conditions shall be in accordance with the agreement between the delivery parties. Unless otherwise specified, the peening strength is set by the method of Annex 1.
6. Base plating
When base plating is performed for the purpose of plating adhesion, diffusion prevention, contamination prevention of plating bath, etc., the type and thickness of the plating shall be determined by the agreement between the delivery parties.
7. Stress relief before plating
If stress relief before plating is specified for steel bases, etc., the conditions are based on the agreement between the delivery parties.
Annex 8 shows the heat treatment conditions for stress relief before plating, which are described as references in the corresponding international standards.
8. Removal of hydrogen brittleness after plating
If hydrogen brittleness removal is specified for steel products, etc., the conditions are based on the agreement between the delivery parties.
Annex 9 shows the heat treatment conditions for removing hydrogen brittleness, which are described as references in the corresponding international standards.
Annex 2 also shows a test method for measuring the reduction in brittleness.
(Remarks Heat treatment must be started within at least 4 hours after plating.)
9. Preparation of test piece
1. Preparation of test piece
Specimens are usually made from products. However, if the plated product itself cannot be used as a test piece, the test is performed using an alternative test piece.
As much as possible, the substitute test piece must be made of the same material as the plated part and under the same plating conditions.
2. Appearance test
The appearance test is performed visually to check for plating defects such as roughness, charring, cracks, pits, and exposure of the substrate, signs of poor adhesion, stains, and scratches.
3. Analytical test
In the chemical composition analysis test, the nickel content and phosphorus content of the plating are measured by the method of Annex 3.
The analysis test of other elements is based on the agreement between the delivery parties.
4. Roughness test
Roughness test is measured by the equipment specified in JIS B 0651.
5. Thickness test
The thickness test shall be one of the microscope cross-sectional test method, electrolytic test method, fluorescent X-ray test method, β-ray test method, eddy current test method, scanning electron microscope test method or mass method specified in JIS H8501. ..
6. Hardness test
The hardness test is measured by the test method specified in JIS Z 2251.
7. Adhesion test
The adhesion test may be performed by a bending test method, a thermal shock test method, a file test method or the following method specified in JIS H8504.
For those requested by the orderer, this test may be performed after heat treatment is performed in accordance with Annex 4.
Punch test Using a spring-loaded center punch whose tip is ground to a diameter of 2 mm, make several dents in the plating at intervals of about 5 mm and measure the adhesion.
8. Porosity test
The porosity test is carried out by the method of Annex 5.
7. Corrosion resistance test
The corrosion resistance test is based on any of the neutral salt spray test method, acetate spray test method, Cass test method, corod coat test method, or Annex 6 specified in JIS H8502.
8. Abrasion resistance test
The wear test is based on the wear test method specified in JIS H8503.
9. Solder wettability test
The solder wettability test shall be conducted by the immersion test specified below, as well as by a method recognized as effective by JIS C0050 or an agreement between the delivery parties.
a) Non-corrosive flux on the test piece (for example, pine or ni dissolved in alcohol)
b) Hold a solder bath with a eutectic composition of H60A, H63A or equivalent specified in JIS Z3282 at 250 ± 5 ° C, and immerse the test piece for 3 seconds.
c) Take out the test piece, shake off excess solder lightly, and cool it in the air.
(Remarks: The number of days left after plating depends on the agreement between the delivery parties)
a) Plating is 9. Test by test, 3. Those that meet the quality regulations are accepted.
b) Specimens are removed from lots of the same parts according to JIS Z 9031.
Remarks 1. The selection of inspection items and test methods is based on the agreement between the delivery parties.
Remarks 2. The number of test pieces, inspection order, inspection target location, and alternative use of test pieces shall be in accordance with the agreement between the delivery parties.
11. How to call plating
The name of plating is expressed in the order of plating type, base metal and minimum thickness or grade of plating.
Example Plating of nickel (90%) phosphorus (10%) 20 μm (or 5th grade) with electroless nickel-phosphorus on steel base
ELp-Fe / Ni (90) -P20
Display the following items on the invoice or delivery note.
a) Plating symbol
b) Processing date
c) Processor name
d) Plating quality test results stated in the ordering party or processing specifications
13. Items to be stated in the purchase order or processing specifications
The ordering party may describe the following items in the purchase order and processing specifications, and omit the additional items by agreement between the delivery parties.
1. Properties and conditions of the base material
2. Plating symbol
3. Effective surface of plating (Present a physical sample as instructed or marked on the drawing)
4. Appearance (final surface roughness, gloss, etc.) (It is recommended to show a limit sample)
5. Inspection method
1. Required heat treatment
(Reference requirements for stress relief treatment before plating and / or hydrogen brittleness removal after plating)
2. Requirements for the process of inducing compressive stress
(Reference, for example, peening before plating)
3. Requirements or constraints for pre-plating
4. Maximum plating thickness
5. Final surface roughness of plating
6. Required plating quality and its test method
(Reference, for example, hardness, chemical composition, corrosion resistance, porosity, wear resistance, solderability)
7. Acceptable plating surface defect type, size, extent and location
8. Special packaging requirements for plated parts
9. Special post-plating treatment
Connection Co., Ltd.
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