Title:
HOT-ROLLED STEEL SHEET WITH EXCELLENT LOW-TEMPERATURE IMPACT TOUGHNESS AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2020/096268
Kind Code:
A1
Abstract:
Disclosed are a hot-rolled steel sheet having a thickness of 6 mm or more and excellent impact properties and a manufacturing method therefor. A hot-rolled steel sheet with excellent low-temperature impact toughness according to an embodiment of the present invention comprises, by wt%, C: greater than 0 to 0.03% or less, Si: 0.1-1.0%, Mn: greater than 0 to 2.0% or less, P: 0.04% or less, Cr: 1.0-10.0%, Ni: greater than 0 to 1.5% or less, Ti: 0.01-0.5%, Cu: greater than 0 to 2.0% or less, N: greater than 0 to 0.03% or less, Al: 0.1% or less, and the remainder of Fe and other inevitable impurities, in which the value of formula (1) below satisfies the range of 200-1,150, the misorientation between crystal grains in a cross-sectional microstructure in the direction perpendicular to a rolling direction is 5° or more, and the average size of crystal grains is 50 µm or less. (1) 1001.5*C + 1150.6*Mn + 2000*Ni + 395.6*Cu - 0.7*Si - 1.0*Ti - 45*Cr - 1.0*P - 1.0*Al + 1020.5*N
Inventors:
KONG JUNG HYUN (KR)
LEE MUN-SOO (KR)
LEE MUN-SOO (KR)
Application Number:
PCT/KR2019/014541
Publication Date:
May 14, 2020
Filing Date:
October 31, 2019
Export Citation:
Assignee:
POSCO (KR)
International Classes:
C22C38/58; B21B1/16; B21B3/00; C21D9/46; C22C38/00; C22C38/02; C22C38/04; C22C38/06; C22C38/42; C22C38/50
Foreign References:
| JP2000144258A | 2000-05-26 | |||
| JP2016191150A | 2016-11-10 | |||
| KR20160123371A | 2016-10-25 | |||
| US9493865B2 | 2016-11-15 | |||
| JP2009068034A | 2009-04-02 |
Other References:
See also references of EP 3859044A4
Attorney, Agent or Firm:
SELIM INTELLECTUAL PROPERTY LAW FIRM (KR)
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