The latest news from Shandong Stainless Steel Pipe Factory: Electroless nickel plating of stainless steel parts (shafts, meshing parts, moving parts, etc.) can improve the uniformity and self-lubrication of the coating, which is better than electroplating chromium. However, the electroless nickel plating of stainless steel is often unsatisfactory because of poor pre-treatment, resulting in unsatisfactory adhesion between the coating and the substrate, and it has become an urgent problem to be solved in actual production. Slotted Channel Unistrut,Channel Unistrut,Slotted Channel Unistrut Fenghua Jade Motor Co., Ltd. , http://www.steelstructure-supplier.com
The original process flow: mechanical polishing → organic solvent degreasing → chemical degreasing → hot water washing → electrochemical degreasing → hot water washing → cold water washing → 30% HCl → cold water washing → 20% HCl (50°C) → cold water washing → flash plating Nickel → Electroless nickel plating.
Disadvantages of the original process: the effect of removing oxide scale by HCL alone is not good; nickel flash plating of complex shapes due to poor covering ability affects the uniformity of electroless nickel plating; and because the process is longer, the fresh surface of stainless steel may be oxidized again. Membrane; flash nickel plating solution can easily contaminate the electroless nickel plating solution. For this reason, someone improved the process.
Improvement of process flow: polishing and deoiling process Same as the original process → mixed acid removal membrane (25% HCl + 8% HNO3 + 10% HF) → cold water → activation (10% HCl + 5% NH4F, 60°C) → hot water → Electroless Nickel.
Advantages of improving the process: 1 The use of mixed acid to remove the insoluble FeCrO4 oxide film on the surface of stainless steel, Si, SiO2, so that the chemical activity of the substrate surface is enhanced; 2 The process is simplified to avoid the reoxidation of fresh stainless steel surface; 3 to increase the preheating process of the substrate , Eliminate the stress caused by temperature difference between the coating and the substrate. Therefore, the electroless nickel plating has a good bonding force with the substrate and the plating speed is fast.
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Electroless Nickel Plating on Stainless Steel Improves Coating Uniformity and Self-Lubrication