STEEL FOR MACHINE STRUCTURE HAVING EXCELLENT COLD WORKABILITY AND COLD-WORKED COMPONENT

摘要

PROBLEM TO BE SOLVED: To provide a steel for machine structures exhibiting satisfactory cold workability during working and exhibiting prescribed hardness and strength after working, and to provide a cold-worked component. SOLUTION: Disclosed is a steel for machine structures having a composition comprising C, Si, Mn, P, S, Al and N as essential components, and the balance Fe with inevitable impurities, and in which the content of N in a solid solution state is ≥0.007%, also, the C content and the N content satisfy the relation of 0.3≥(10C+N), while a ferrite single phase structure is formed, and the average crystal grain size of ferrite lies in the range of 10 to 200 μm. COPYRIGHT: (C)2010,JPO&INPIT