Journal of South China University of Technology (Natural Science Edition) ›› 2016, Vol. 44 ›› Issue (2): 140-146.doi: 10.3969/j.issn.1000-565X.2016.02.020

• Materials Science & Technology • Previous Articles    

Investigation into Deformation Mechanism of Medium Manganese Q&P Steel Based on Stacking Fault Energy

LIN Zhang-guo CHEN Jia-yong TANG Di JIANG Hai-tao DUAN Xiao-ge   

  1. Engineering Research Institute,University of Science and Technology Beijing,Beijing 100083,China
  • Received:2014-12-15 Revised:2015-09-08 Online:2016-02-25 Published:2016-01-04
  • Contact: 江海涛(1976-) ，男，副教授，主要从事汽车用钢材料的开发与研究． E-mail:nwpujht@163.com
  • About author:吝章国(1971-) ，男，高级工程师，主要从事高端钢铁产品生产技术研究．E-mail:linzhangguo@hebgtjt．com
  • Supported by:
    Supported by the National Natural Science Foundation of China( 51271035)

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Abstract: In this paper,first,the stacking fault energy of the retained austenite in medium manganese Q&P steels respectively with a Mn content of 5% and 7% were calculated by using the thermodynamic model of stacking fault energy,and the effect of carbon partition during the heat treatment on the stacking fault energy was analyzed.Then,the deformation mechanism of the steel under tensile strain was investigated by means of XRD,SEM and TEM,and the relationship between the stacking fault energy and the deformation mechanism was explored.The results show that ( 1) carbon partition should be considered during the calculation of the stacking fault energy of medium manganese Q&P steels; ( 2) the stacking fault energy of 7Mn-1. 5Si-0. 2C sample is 4. 55mJ /m2,and that of 5Mn-1. 5Si-0. 2C sample is 17. 8 mJ /m2 ; ( 3) there is a linear relationship between the natural logarithm of retained austenite content and the deformation; and ( 4) TRIP effect is the main deformation mechanism of medium manganese Q&P steels,which is also verified by the calculated results of the stacking fault energy.

Key words: Q&P steel, stacking fault energy, deformation mechanism, retained austenite, heat treatment, carbon partition