Search International and National Patent Collections

1. (WO2018101451) STEEL FOR SOFT NITRIDING, AND COMPONENT

Pub. No.:    WO/2018/101451    International Application No.:    PCT/JP2017/043211
Publication Date: Fri Jun 08 01:59:59 CEST 2018 International Filing Date: Fri Dec 01 00:59:59 CET 2017
IPC: C22C 38/00
C22C 38/60
C21D 1/06
C21D 8/06
C21D 9/32
Applicants: JFE STEEL CORPORATION
JFEスチール株式会社
Inventors: IHARA Naoya
井原 直哉
KASAI Masayuki
笠井 正之
IWAMOTO Takashi
岩本 隆
NISHIMURA Kimihiro
西村 公宏
Title: STEEL FOR SOFT NITRIDING, AND COMPONENT
Abstract:
Provided is a steel for soft nitriding having a component composition including 0.01% to 0.10% C, 1.0% or less of Si, 0.5% to 3.0% Mn, 0.02% or less of P, 0.06% or less of S, 0.30% to 0.9% Cr, 0.005% to 0.200% Mo, 0.02% to 0.50% V, 0.003% to 0.150% Nb, 0.005% to 0.200% Al, 0.0200% or less of N, 0.0005% to 0.0200% Sb, 0.3% or less (including 0%) of W, 0.3% or less (including 0%) of Co, 0.2% or less (including 0%) of Hf, 0.2% or less (including 0%) of Zr, and 0.1% or less (including 0%) of Ti in a range satisfying the formula 9.5 ≤ ([Cr]/52 + [V]/50.9 + [Nb]/92.9 + M) × 103 ≤ 18.5, the remainder being Fe and unavoidable impurities, and the area ratio of a bainite phase with respect to the steel structure as a whole being over 50%, whereby precipitation of Cr, V, and Nb in a surface layer is significantly suppressed, thereby ensuring hardened layer depth.