Quasi-Situ Characterization of Deformation in Low-Carbon Steel with Equiaxed and Lamellar Microstructure Treated by the Quenching and Partitioning Process
来源期刊：Acta Metallurgica Sinica2020年第12期
论文作者：Pengfei Gao Weijian Chen Feng Li Beijia Ning Zhengzhi Zhao
摘 要：The relationship between microstructure morphology and mechanical properties of the low-carbon steel（Fe-0.20 C-2.59 Mn-2.13 Si） treated by diff erent intercritical annealed quenching and partitioning（Q&P） processes was investigated through interrupted tensile tests plus quasi-situ electron backscatter diff raction measurements. Results show that size and distribution of retained austenite（RA） directly aff ect the sequence of deformation induced martensitic transformation. As strain increases,the equiaxed RA grains wrapped by ferrite transform fi rst, followed by the equiaxed and fi lm-like RA grains adjacent to martensite. Compared with traditional intercritical annealed Q&P steel with equiaxed structure, the steel with quenching pretreatment contains uniform lamellar structure and the relatively fi lm-like type of RA, leading to the higher yield strength,tensile strength, and elongation, as well as the steady increase in dislocation density upon straining.
Pengfei Gao1,2，Weijian Chen1,2，Feng Li1,2，Beijia Ning1,2，Zhengzhi Zhao1,2
1. Collaborative Innovation Center of Steel Technology ,University of Science and Technology Beijing2. Beijing Laboratory of Metallic Materials and Processing for Modern Transportation
摘 要：The relationship between microstructure morphology and mechanical properties of the low-carbon steel（Fe-0.20 C-2.59 Mn-2.13 Si） treated by diff erent intercritical annealed quenching and partitioning（Q&P） processes was investigated through interrupted tensile tests plus quasi-situ electron backscatter diff raction measurements. Results show that size and distribution of retained austenite（RA） directly aff ect the sequence of deformation induced martensitic transformation. As strain increases,the equiaxed RA grains wrapped by ferrite transform fi rst, followed by the equiaxed and fi lm-like RA grains adjacent to martensite. Compared with traditional intercritical annealed Q&P steel with equiaxed structure, the steel with quenching pretreatment contains uniform lamellar structure and the relatively fi lm-like type of RA, leading to the higher yield strength,tensile strength, and elongation, as well as the steady increase in dislocation density upon straining.
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