公开(公告)号：US10570478B2

公开(公告)日：2020-02-25

申请号：US15319115

申请日：2015-06-08

申请人： KOBE STEEL, LTD.

发明人： Yuki Sasaki ,  Takehiro Tsuchida ,  Takuya Kochi ,  Koji Yamashita ,  Masamichi Chiba ,  Kei Masumoto ,  Masayuki Sakata

IPC分类号： C22C38/04 ,  C21D9/52 ,  C21D8/06 ,  C22C38/18 ,  B21B1/22 ,  C21D6/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/16 ,  C22C38/20

摘要： Provided is a steel for a mechanical structure for cold working, which contains C, Si, Mn, P, S, Al and N and in which the metal structure includes pearlite and ferrite, the total areal proportion of pearlite and ferrite relative to the overall structure is 90% or higher, the average circle-equivalent diameter of bcc-Fe crystal grains surrounded by large angle grain boundaries is 5-15 μm, the average aspect ratio of pro-eutectoid ferrite crystal grains is 3.0 or lower, and the average spacing at the narrowest pearlite lamellar spacing is 0.20 μm or less.