• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2018, Vol. 54 ›› Issue (16): 86-92.doi: 10.3901/JME.2018.16.086

• 材料科学与工程 • 上一篇    下一篇

共析钢在冷轧过程中的组织演变和强化机制

杨才定1,2, 刘烨1   

  1. 1. 上海大学材料科学与工程学院 上海 200072;
    2. 宝山钢铁股份有限公司中央研究院 上海 201900
  • 收稿日期:2017-11-15 修回日期:2018-03-26 出版日期:2018-08-20 发布日期:2018-08-20
  • 通讯作者: 杨才定(通信作者),男,1981年出生,博士研究生,高级工程师。主要研究方向为汽车用特殊钢、高强钢。E-mail:yangcaiding@baosteel.com
  • 基金资助:
    国家自然科学基金资助项目(51271107)。

Microstructure Evolution and Mechanical Hardening of Eutectoid Steel During Cold-rolling

YANG Caiding1,2, LIU Ye1   

  1. 1. School of Materials Science and Engineering, Shanghai University, Shanghai 200072;
    2. R & D Center, Baoshan Iron & Steel Co., Ltd, Shanghai 201900
  • Received:2017-11-15 Revised:2018-03-26 Online:2018-08-20 Published:2018-08-20

摘要: 为了更有效利用索氏体组织具有的超细片层状结构来提升钢板性能,利用TEM和EBSD等方法研究索氏体化处理后的Fe-0.8C钢经过10%~90%的冷轧变形后所产生的组织变化,并结合拉伸试验方法研究了不同冷轧变形量下微观组织变化和力学性能之间的关系,揭示材料的强化机理。结果表明:随着冷轧压下量的增加,珠光体片层间距逐渐降低,在压下量90%的情况下片层距减小至57 nm;冷轧造成的局部塑性应变(KAM值)在低应变下迅速提高,在70%压下量时达到峰值;冷轧过程导致片层铁素体中出现大量位错,并且随着压下量的增加而迅速增加;过拉伸性能测试发现,随着冷轧压下量的增加,拉伸性能随之增加,其强化机制符合界面强化模型,在冷轧压下量达到90%时,可获得2300 MPa以上的高强度冷轧钢板,为开发高强度钢提供了一种新的思路。

关键词: 高强钢, 共析钢, 冷轧, 强化机制

Abstract: In order to make more efficient use of the ultra-fine lamellar structure of sorbite to improve the mechanicalproperties of steel, the microstructure evolution of patenting Fe-0.8C steel with various amounts of rolling(from 10-90% reduction) are studied by TEM and EBSD etc. Combing with the tensile test, the strengthening mechanism of the steel is revealed by investigating with the relationship between microstructure changes and mechanical properties caused by different cold rolling reduction.The results showed that the interlamellar spacing(ILS) is gradually decreased with increasing of cold-rolled reduction and is refined to 57 nm at 90% reduction. The local plastic strain (KAM value) caused by cold rolling is rapidly increasing at low strain and reached its peak at 70% reduction. It is observed that the dislocations located in the lamellar ferrite are mainly concentrated in the rolling process and increased with increasing of cold-rolled reduction. The tensile strength of cold-rolled specimens increased with rolling reduction, and the strengthening mechanism is in accordance with the interface strengthening model. After 90% cold-rolled reduction, the tensile strength over 2300 MPa is achieved. It provides a new idea for the development of high strength steel.

Key words: cold-rolling, eutectoid steel, high strength steel, strengthening mechanism

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