Characteristics of Deformation Layer for Vermicular Iron under Dry Sliding Friction

At room temperature, dry sliding wear tests were carried out using pin-on disc test rig, in which the pin is made of vermicular iron and the disc is made of 40Cr steel. The microstructures of the frictional surfaces for the pin specimens were investigated. Under the action ofboth frictional heat and frictional shearing stress, a plastic deformation layer under the frictional surface is formed. The morphology and properties of the plastic deformation layer depend on specimen material, contact pressure and frictional shearing stress. In the plastic deformation layer, the phosphorous mass percent varies at different depth and results in different hardness. On the outer side of surface, the hardness is the biggest and the phosphorous mass percent is the highest. They become gradually small from outer side to inner side of the surface.