Hot ductility behavior of a Fe–0.3C–9Mn–2Al medium Mn steel
来源期刊：International Journal of Minerals Metallurgy and Materials2021年第3期
论文作者：Yong-jin Wang Shuai Zhao Ren-bo Song Bin Hu
摘 要：The hot ductility of a Fe–0.3C–9Mn–2Al medium Mn steel was investigated using a Gleeble 3800 thermo-mechanical simulator. Hot tensile tests were conducted at different temperatures（600–1300°C） under a constant strain rate of 4 × 10-3 s-1. The fracture behavior and mechanism of hot ductility evolution were discussed. Results showed that the hot ductility decreased as the temperature was decreased from1000°C. The reduction of area（RA） decreased rapidly in the specimens tested below 700°C, whereas that in the specimen tested at 650°C was lower than 65%. Mixed brittle–ductile fracture feature is reflected by the coexistence of cleavage step, intergranular facet, and dimple at the surface. The fracture belonged to ductile failure in the specimens tested between 720–1000°C. Large and deep dimples could delay crack propagation. The change in average width of the dimples was in positive proportion with the change in RA. The wide austenite–ferrite intercritical temperature range was crucial for the hot ductility of medium Mn steel. The formation of ferrite film on austenite grain boundaries led to strain concentration. Yield point elongation occurred at the austenite–ferrite intercritical temperature range during the hot tensile test.
Yong-jin Wang1，Shuai Zhao1，Ren-bo Song1，Bin Hu2
1. School of Materials Science and Engineering, University of Science and Technology Beijing2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing
摘 要：The hot ductility of a Fe–0.3C–9Mn–2Al medium Mn steel was investigated using a Gleeble 3800 thermo-mechanical simulator. Hot tensile tests were conducted at different temperatures（600–1300°C） under a constant strain rate of 4 × 10-3 s-1. The fracture behavior and mechanism of hot ductility evolution were discussed. Results showed that the hot ductility decreased as the temperature was decreased from1000°C. The reduction of area（RA） decreased rapidly in the specimens tested below 700°C, whereas that in the specimen tested at 650°C was lower than 65%. Mixed brittle–ductile fracture feature is reflected by the coexistence of cleavage step, intergranular facet, and dimple at the surface. The fracture belonged to ductile failure in the specimens tested between 720–1000°C. Large and deep dimples could delay crack propagation. The change in average width of the dimples was in positive proportion with the change in RA. The wide austenite–ferrite intercritical temperature range was crucial for the hot ductility of medium Mn steel. The formation of ferrite film on austenite grain boundaries led to strain concentration. Yield point elongation occurred at the austenite–ferrite intercritical temperature range during the hot tensile test.
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