Patent ID: 8430974

Claim:
A carburized and induction-hardened component formed by carburizing and then induction-hardening a steel consisting essentially of, by mass: C: minimum 0.08% and under 0.3%; Si: 0.0% to 2.0%; Mn: from 1.3% to 3.0%; P: maximum 0.03%; S: from 0.005% to 0.05%; Cr: 0.0% to 3.0%; Mo: 0.0% to 1.0%; O: maximum 0.0025%; and N: from 0.005% to 0.03%; and further comprising either or both of, by mass, Al: from 0.005% to 0.05%, and Ti: from 0.005% to 0.05%; and still further comprising either or both of, by mass, V: from 0.01% to 0.3%, and Nb: from 0.01% to 0.3%; and a balance of Fe and unavoidable impurities, the carburized and induction-hardened component having a surface layer with hardness of at least 55 HRC and a core portion with a hardness of from 20 to 50 HRC, wherein the core portion does not have a martensite structure and wherein the core portion has an area ratio of a bainite structure in cross section of at least 70%.