Abstract:Ultrafast heating (UFH) process has attracted a wide attention due to its high efficiency and economic advantages. To investigate the influence of UFH on the microstructural evolution and mechanical performance of the cold-rolled IF steel sheet, two types of UFH processes, i.e. the direct UFH and a preheating stage were performed. Compared with the conventional continuous annealing (CA) process at 870 ℃ for 270 s, the direct UFH process at 200-500 ℃/s to 870 ℃ could effectively refine the grain sizes. In particular, the UFH at 500 ℃/s could obviously improve the yield strength, for example the tensile strength approximately reached 300 MPa, while the total elongation remained 43%. Compared with direct heating, the grains can be further refined after the introduction of 400 ℃ preheating section, and the recrystallization temperature can be significantly increased due to the recovery consumption of storage. However, the preheating stage also caused {110}<110> texture appear and the weaker texture strength, leading to thinning in the process of stretch deformation, which resulted in the necking advance, thus reducing the plasticity.
韩建胜, 温鹏宇, 罗海文. 超快速加热对冷轧IF钢组织和力学性能的影响[J]. 中国冶金, 2020, 30(5): 42-46,69.
HAN Jian-sheng, WEN Peng-yu, LUO Hai-wen. Effect of ultra-fast heating on microstructural evolution and mechanical properties of IF steel[J]. China Metallurgy, 2020, 30(5): 42-46,69.
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