Title:
56 KG-GRADE LOW-YIELD-RATIO ULTRAHIGH-STRENGTH MARITIME WORK STEEL PLATE AND PREPARATION METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2023/109005
Kind Code:
A1
Abstract:
The present invention belongs to the field of steel material preparation, and relates to a 56 kg-grade low-yield-ratio ultrahigh-strength maritime work steel plate and a preparation method therefor. The composition design of the present invention comprises the following components: C: 0.05%-0.012%, Si: 0.20%-0.50%, Mn: 1.00%-1.50%, P ≤ 0.015%, S ≤ 0.005%, Nb: 0.010%-0.030%, Ti: 0.010%-0.030%, Cr: 0.20%-0.45%, V: 0.010%-0.035%, Cu: 0.20%-0.50%, Mo: 0.10%-0.25%, Ni: 0.50%-0.95%, Als: 0.015%-0.045％, N ≤ 0.004％, and the balance being Fe and inevitable impurities, wherein the carbon equivalent Cev is ≤ 0.55, and the Pcm is is ≤ 0.25. According to the present invention, Nb, V and Ti multi-element microalloying elements are utilized, Mo, Ni and other refined and precipitated second-phase particles are added, the refined grain strengthening and precipitation strengthening effects are improved, and the subcritical quenching and high-temperature tempering processes are combined, such that the steel plate has a ReH ≥ 600Mpa, Rm of 730 Mpa to 800 Mpa, a yield ratio ≤ 0.82, and transverse and longitudinal impact energy at -60ºC of ≥ 200 J; in addition, the resulting second-phase particles are dispersed and distributed in a welding heat affected zone, so that the strength of a welding joint is improved, an input of 150-220 kJ/cm can be achieved, and the impact energy at -60ºC after welding is ≥ 100 J.
Inventors:
MA HENG (CN)
HE KANG (CN)
WANG ZHONGXUE (CN)
WANG TENGFEI (CN)
CHEN AIJIAO (CN)
ZHANG QINGPU (CN)
LI YAN (CN)
WANG YUEXIANG (CN)
ZHANG CHANGHONG (CN)
HE KANG (CN)
WANG ZHONGXUE (CN)
WANG TENGFEI (CN)
CHEN AIJIAO (CN)
ZHANG QINGPU (CN)
LI YAN (CN)
WANG YUEXIANG (CN)
ZHANG CHANGHONG (CN)
Application Number:
PCT/CN2022/092982
Publication Date:
June 22, 2023
Filing Date:
May 16, 2022
Export Citation:
Assignee:
LAIWU STEEL YINSHAN SECTION CO LTD (CN)
SHANDONG IRON & STEEL CO LTD (CN)
SHANDONG IRON & STEEL CO LTD (CN)
International Classes:
C22C38/02; B21B1/46; B21B37/74; C21D1/18; C21D8/02; C22C33/06; C22C38/04; C22C38/06; C22C38/42; C22C38/44; C22C38/46; C22C38/48; C22C38/50
Domestic Patent References:
| WO2014092129A1 | 2014-06-19 |
Foreign References:
| CN114250416A | 2022-03-29 | |||
| CN103938108A | 2014-07-23 | |||
| CN110791702A | 2020-02-14 |
Attorney, Agent or Firm:
FASTA INTELLECTUAL PROPERTY LIMITED (CN)
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