For the excellent mechanical structure in cold workability steel and cold work steel parts

摘要

PPROBLEM TO BE SOLVED: To provide a steel for machine structures which not only has excellent cold workability but also can secure prescribed hardness and strength after working, and to provide a steel component for cold working obtained by using the steel for machine structures. PSOLUTION: In this steel, a chemical component composition in which, while controlling the content of N as a solid-soluted state to 0.007 to 0.018%, the relations in equalities (1) and (2) are satisfied is suitably regulated, and the steel has a structure where the area ratio of pearlite and cementite is ≤3%: (1) 0.5≥(10[C]+[N]), where [C] and [N] denote the contents (mass%) of C and N, respectively; and(2) 0≥126[C]+3[Mn]+84[S]-10 where [C], [Mn] and [S] denote the contents (mass%) of C, Mn and S, respectively. PCOPYRIGHT: (C)2010,JPO&INPIT