Patent ID: 8034199
Filing Date: 2011-10-11
Classification: C22C

Abstract:
1. A case-hardening steel excellent in cold forgeability and low carburization distortion property used in cold forged large components and complexly shaped components consisting of, in mass %, C: 0.07% to 0.3%, Si: 0.01% to 0.15%, Mn: 0.1% to 0.7%, P: 0.03% or less, S: 0.002% to 0.10%, Al: 0.01% to 0.08%, Cr: 0.7% to 1.5%, Ti: 0.01% to 0.029%, B: 0.0005% to 0.005%, N: 0.008% or less, and the balance of Fe and unavoidable impurities, and having a metallographic structure comprising 65% or greater of ferrite and 15% or less of bainite by means of a cooling rate of 0.3° C./sec or less, and having cold deformation resistance of 650 MPa or less.