What are the methods of corrosion resistance of fasteners

1) Coating
Perhaps common gasket corrosion protection treatment is coating. Depending on the material from which the gasket is made, it may rust or corrode when exposed to moisture. For example, high carbon steel is prone to rust and corrosion. However, a coating can be applied to the gasket to prevent this from happening. Zinc coatings are particularly effective because of their natural rust and corrosion resistance.

2) Electroless Plating
Electroless plating is an anti-corrosion process that involves the use of special chemicals to create rust- and corrosion-resistant surface on metal objects, such as gaskets. According to Wikipedia, nickel-phosphorus alloys are commonly used for electroless plating of washers. A nickel-phosphorus alloy is sprayed onto the surface of the gasket, which initiates a chemical reaction that protects the gasket from rust and corrosion.

3) Browning
Also known as bluing, browning involves the use of salt or saline solutions to create an object's corrosion-resistant surface. During this treatment, the gasket is submerged in salt or saline solution. This induces oxidation, which in turn creates a corrosion-resistant surface on the gasket. Browning is unique compared to the other corrosion-resistant treatments listed here because of its ability to change the color of the gasket. After tanning, the washers have a glossy and colorful appearance.

4) Phosphating
Another common anti-corrosion treatment for gaskets is phosphating. By phosphating, a solution of zinc phosphate and oil is applied to the surface of the washing machine. The presence of this new layer creates a barrier between the washing machine itself and its surroundings, protecting it from rust and corrosion.

5) Electroplating
Finally, electroplating refers to the use of electrical current to apply chromium or silver to an object. When an electrical current is applied to these metals, it reduces them to cations, which are then distributed evenly across the gasket to form a coating.