Effect of microstructure on rolling/sliding wear of low carbon bainitic steels

The microstructures of five molybdenum-boron, low carbon, bainitic steels were characterized using transmission electron microscopy and the wear behavior of the steels determined under severe rolling/sliding contact. Wear resistance was enhanced by the presence of carbide-free bainite. The degree to which the microstructure contained this form of bainite was increased by higher carbon content and cooling rate. A 0.18% C, 1.13% Si steel in the as-quenched condition exhibited wear behavior as good as a 0.8% C, head-hardened, pearlitic rail steel.