Title:
GRADIENT STEEL MATERIAL HAVING HIGH-PLASTICITY SURFACE LAYER AND HIGH-STRENGTH INNER LAYER, AND MANUFACTURING METHOD
Document Type and Number:
WIPO Patent Application WO/2020/135690
Kind Code:
A1
Abstract:
A gradient steel material having a high-plasticity surface layer and a high-strength inner layer, and a manufacturing method. Weight percentages of the components thereof are: C≤0.15%, Si≤1%, Mn≤1.5%, and the remainder is Fe and inevitable impurities, the surface layer of the steel material being a ferrite tissue, and the inner layer being a ferrite + bainite tissue. The manufacturing method therefor comprises: smelting, casting, rolling, and a heat treatment, wherein in the heat treatment step, a steel material is heated to an austenite temperature Ac3 or more and kept at said temperature for more than 3 min; thereafter, the material is cooled to a temperature range between Ar3 and Ar1 in a two-phase zone at a cooling rate of less than 0.5°C/s, and is then cooled to room temperature at a cooling rate of greater than 5°C/s. The present steel material does not need to be obtained by means of the compound preparation of different materials as only a single material is processed. At the same time, the composition of the steel material is simple. Although the internal and external tissues are different, the difference is a gradual process, and the metallurgical bonding strength between the two is good.
More Like This:
Inventors:
ZHANG SUOQUAN (CN)
JIAO SIHAI (CN)
DING JIANHUA (CN)
WU KOUGEN (CN)
JIAO SIHAI (CN)
DING JIANHUA (CN)
WU KOUGEN (CN)
Application Number:
PCT/CN2019/129094
Publication Date:
July 02, 2020
Filing Date:
December 27, 2019
Export Citation:
Assignee:
BAOSHAN IRON & STEEL (CN)
International Classes:
C22C38/00; C21D1/00; C21D8/00
Domestic Patent References:
WO2018110152A1 | 2018-06-21 |
Foreign References:
CN103459643A | 2013-12-18 | |||
CN105143486A | 2015-12-09 | |||
CN107663609A | 2018-02-06 | |||
CN201110045798A | 2011-02-25 | |||
CN201310211969A | 2013-05-31 | |||
CN201410707715A | 2014-11-28 | |||
CN201310212003A | 2013-05-31 | |||
CN201310213371A | 2013-05-31 | |||
CN201510173144A | 2015-04-13 | |||
CN201611223874A | 2016-12-27 | |||
CN201510621011A | 2015-09-25 | |||
CN201510173145A | 2015-04-13 | |||
CN201520878950U | 2015-11-06 | |||
CN201510738639A | 2015-11-03 | |||
CN201620972383U | 2016-08-30 | |||
CN201720527381U | 2017-05-12 | |||
CN201810506236A | 2018-05-19 | |||
CN201711015280A | 2017-10-25 |
Other References:
See also references of EP 3885460A4
Attorney, Agent or Firm:
WATSON & BAND INTELLECTUAL PROPERTY AGENT LTD. (CN)
Download PDF: