Sulfamate Nickel Hard Chrome
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Sulfamate nickel hard chrome is a process combining two functional coatings that has a unique result. The finish provides the excellent wear, hardness, and lubricity of traditional hard chrome, with the outstanding corrosion protection of sulfamate nickel plating.
Because of its hardness, anti-galling characteristics, and low coefficient of friction, hard chrome has long been the preferred coating for the piston rods of hydraulic cylinders and other industrial uses. While best known for its excellent wear characteristics, hard chrome is not always the best choice for long lasting corrosion protection due to the natural characteristics of chrome, which is micro-cracked. Under microscopic examination you will find spider webs of cracks that make the substrate material susceptible to corrosion. In contrast, nickel is a barrier coating, which exhibits superior corrosion protection and is used in applications where this is a critical performance requirement.
The combination of sulfamate nickel as an undercoating and hard chrome as the topcoat is an excellent choice for parts that require superior corrosion protection and outstanding wear characteristics. The two tests commonly used to measure corrosion resistance are ASTM B117 salt spray and ASTM B368 copper accelerated acetic acid (CASS) salt spray tests. Both of these are performed in our “in house” laboratory, and outstanding results have been achieved when sulfamate nickel and hard chrome are used in conjunction.
If you think you have a product that could benefit from sulfamate nickel hard chrome please call Wynn Lafferty at 402.473.2135.