Title:
ULTRA-THICK STEEL MATERIAL HAVING EXCELLENT STRENGTH AND LOW TEMPERATURE IMPACT TOUGHNESS FOR FLANGE, AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2023/121186
Kind Code:
A1
Abstract:
Provided are an ultra-thick steel material having excellent strength and low-temperature impact toughness for flanges and a method for manufacturing same. The steel material of the present invention comprises, by wt%, C: 0.05-0.2%, Si: 0.05-0.5%, Mn: 1.0-2.0%, Al: 0.005-0.1%, P: 0.01% or less, S: 0.015% or less, Nb: 0.001-0.07%, V: 0.001-0.3%, Ti: 0.001-0.03%, Cr: 0.01-0.3%, Mo: 0.01-0.12%, Cu: 0.01-0.6%, Ni: 0.05-1.0%, Ca: 0.0005-0.004%, and the balance of Fe and inevitable impurities, has Ceq satisfying the range of 0.35-0.55 as calculated by the following equation, has a mean ferrite grain size of 25㎛ or less in the central portion thereof, and contains a microstructure including 5-30 area% of pearlite and the balance of ferrite.
Inventors:
KIM DAE-WOO (KR)
Application Number:
PCT/KR2022/020730
Publication Date:
June 29, 2023
Filing Date:
December 19, 2022
Export Citation:
Assignee:
POSCO CO LTD (KR)
International Classes:
C22C38/58; B21B1/02; C22C38/42; C22C38/44; C22C38/46; C22C38/48; C22C38/50
Foreign References:
| KR20210079847A | 2021-06-30 | |||
| KR20210032833A | 2021-03-25 | |||
| CN109338219A | 2019-02-15 | |||
| KR101253890B1 | 2013-04-16 | |||
| JP5928654B2 | 2016-06-01 | |||
| KR20120075246A | 2012-07-06 | |||
| KR20170095307A | 2017-08-22 |
Attorney, Agent or Firm:
C&S PATENT AND LAW OFFICE (KR)
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