Koichi Uchino

Effects of carbon content on wear property in pearlitic steels

To clarify the effects of carbon content on the rolling contact wear in steels, the authors conducted a two-cylinder rolling contact wear test using pearlitic steels with a carbon content in a range from 0.8 to 1.0 mass% and studied the relationship between the carbon content and the rolling contact wear. In addition, the authors examined the dominating factor in the rolling contact wear in pearlitic steels and the work-hardening rate of the rolling contact surface. The main findings obtained are as follows: (1) The wear resistance of pearlitic steels improve as carbon content increases. (2) The dominating factor in the rolling contact wear of pearlitic steels is the rolling contact surface hardness (RCSH). (3) The improved wear resistance of pearlitic steels is attributable to an increase in RCSH due to raising the work-hardening rate of the rolling contact surface as carbon content increases. (4) The reason why the work-hardening rate of the rolling contact surface of pearlitic steel rises as carbon content increases is considered to be as follows: an increase in the cementite density increases the amount of dislocation in the matrix ferrite and promotes the grain refinement of the matrix ferrite. As a result, the matrix ferrite is strengthened through the promotion of dislocation hardening and grain refinement.