Title:
COLD ROLLED STEEL SHEET AND PLATED STEEL SHEET WHICH HAVE EXCELLENT BAKE-HARDENABILITY AND ROOM-TEMPERATURE ANTIAGING PROPERTY, AND MANUFACTURING METHODS THEREFOR
Document Type and Number:
WIPO Patent Application WO/2021/125644
Kind Code:
A1
Abstract:
A cold rolled steel sheet having excellent bake-hardenability and room-temperature anti-aging property, according to one aspect of the present invention, comprises, by wt%, 0.002-0.015%, of C, 1.5-3.0% of Mn, 0.03% or less of P, 0.01% or less of S, 0.01% or less of N, 0.02-0.06% of sol. Al, 1.2% or less of Cr (excluding 0%), and the balance of Fe and inevitable impurities, comprises, as a microstructure, ferrite, which is a matrix structure, and the balance of hard tissue, and has a hard tissue occupancy ratio (V) that can be 70% or more in grain boundary triple points defined by the following relation 1. [Relation 1] V(%) = {Vtp / (Vgb + Vtp)} × 100
In relation 1, Vgb means the number of hard tissues observed in ferrite grain boundaries within an observation region, and Vtp means the number of hard tissues observed in ferrite grain boundary triple points within the observation region.
More Like This:
Inventors:
LEE JE-WOONG (KR)
CHOI YONG-HOON (KR)
HA YU-MI (KR)
HAN SEONG-HO (KR)
CHOI YONG-HOON (KR)
HA YU-MI (KR)
HAN SEONG-HO (KR)
Application Number:
PCT/KR2020/017650
Publication Date:
June 24, 2021
Filing Date:
December 04, 2020
Export Citation:
Assignee:
POSCO (KR)
International Classes:
C22C38/38; B21B1/24; B21B3/00; C21D8/02; C21D8/12
Foreign References:
| KR20170012865A | 2017-02-03 | |||
| US4496400A | 1985-01-29 | |||
| JPH07300623A | 1995-11-14 | |||
| KR20050068358A | 2005-07-05 | |||
| CN106244923A | 2016-12-21 | |||
| JPH06306531A | 1994-11-01 |
Other References:
See also references of EP 4079915A4
Attorney, Agent or Firm:
C&S PATENT AND LAW OFFICE (KR)
Download PDF: