公开(公告)号：US20240352562A1

公开(公告)日：2024-10-24

申请号：US18258704

申请日：2021-09-29

Applicant: AICHI STEEL CORPORATION

Inventor： Takayoshi SUGIURA ,  Ryota TAKAO ,  Tomoaki YUTANI ,  Takeyuki SHIMADA ,  Shuhei YOKOI

IPC: C22C38/04 ,  C21D1/06 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/28 ,  C22C38/32

CPC classification number: C22C38/04 ,  C21D1/06 ,  C22C38/001 ,  C22C38/02 ,  C22C38/06 ,  C22C38/28 ,  C22C38/32 ,  C21D2211/005

Abstract: A case hardening steel for warm forging at a forging temperature of 850° C. to 1100° C. The case hardening steel has a chemical composition including: C: 0.15 to 0.23%; Si: 0.60 to 0.95%; Mn: 0.60 to 1.20%; P: 0.035% or less; S: 0.035% or less; Cr: 1.50% or less (excluding 0%); Al: 0.050% or less; Ti: 0.01 to 0.05%; B: 0.0005 to 0.0050%; N: 0.0020 to 0.0200%; Mo: 0.20% or less as an optional element; Nb: 0.01 to 0.05% as an optional element; and Fe, and satisfies Formulae 1 and 2: Formula 1: 90≥−120*C+20.1*Si−5.3*Mn−8.5*Mo+96≥80, Formula 2: 160≥40*Si+39*Mn+10*Cr+30*Mo+84≥145.