Title:
PRODUCTION OF HIGH TOUGHNESS STEEL PLATE FOR LOW TEMPERATURE USE
Document Type and Number:
Japanese Patent JPH0941088
Kind Code:
A
Abstract:
To produce the steel plate improved in toughness at low temp. and having a wide permissible hardening temp. range.
A slab, having a composition consisting of, by weight, 0.04-0.12% C, 0.02-0.80% Si, 0.05-0.8% Mn, ≤0.01% P, ≤0.005% S, 6.5-12.0% Ni, 0.01-0.10% Al, ≤0.0035% N, and the balance essentially Fe, is held at 1,200-1,350°C for ≥24hr to undergo diffusion heat treatment, followed by air cooling down to room temp. Subsequently, the slab is hot-rolled to the prescribed plate thickness, and the resultant plate is heated to a temp. between the Ac3 transformation point and (Ac3 transformation point +200°C), cooled, and then tempered at a temp. between 450°C and (Ac1 transformation point +70°C).
Inventors:
MORIKAGE YASUSHI
KAWABATA FUMIMARU
AMANO KENICHI
KAWABATA FUMIMARU
AMANO KENICHI
Application Number:
JP19545195A
Publication Date:
February 10, 1997
Filing Date:
July 31, 1995
Export Citation:
Assignee:
KAWASAKI STEEL CO
International Classes:
C21D8/02; C21D9/46; C22C38/00; C22C38/08; C22C38/16; (IPC1-7): C22C38/00; C21D8/02; C21D9/46; C22C38/08; C22C38/16
Attorney, Agent or Firm:
Junzo Ogawa (1 person outside)