An Experimental Analysis on Rubber-Metal Contact Stress Corrosion in Seawater

Rubber components for liquid sealing are widely used in corrosive environments such as marine applications or food-processing equipment. Corrosion is found more frequently at the rubber-metal contact area or its adjacent area than non-contact area in certain situation. While the role of rubber components in corrosion is not fully understood, the deterioration of rubber in aqueous environments may release chloride or acid to accelerate the corrosion process. Contact stress and local liquid entrapment may also affect the corrosion process. In this work, corrosion of rubber parts in combination with different metals and different contact pressure in seawater is studied experimentally. Metals used include titanium, bronze, nickel, aluminum, stainless steel, and 4130 steel. O-rings with different cross section shapes are used to study the role of different contact area shapes in corrosion process. The contact area of rubber components and the metals are designed to have different contact stress. It is found that the corrosion of metals is accelerated by interaction with rubber and contact stress in seawater. The corrosion initiates from the contact area of metals with rubber O-rings. Different materials show different corrosion behaviors in seawater.