Precipitates, microstructure and properties of Ti-IF steel with high plastic strain ratio
HAN Yun1, QIU Mu-sheng1, ZOU Ying1, WANG Gang2
1. Jingtang Technology Center, Research Institute of Technology, Shougang Group Co., Ltd., Beijing 100043, China; 2. Technology and Quality Department, Dongfeng Peugeotcitroen Automobile Company Ltd., Wuhan 430056, Hubei, China
Abstract:In order to study the effect of hot rolling and final product precipitates on the plastic strain ratio of Ti-IF steel, The precipitation behavior of micro-alloyed carbides during hot rolling and galvanized annealing of two Ti-IF steels at different hot-rolling heating temperatures were studied by universal testing machine, transmission electron microscope (TEM), energy dispersive spectrometer(EDS) and electron backscattered diffraction(EBSD) analysis methods combined with thermodynamic calculation. The results showed that the size of the precipitates of hot-rolled coils increased with the decrease of hot-rolling heating temperature, the size of the precipitates of Ti4C2S2 and its composite with Cu2S increased from 50-100 nm to 100-200 nm. The precipitates are mainly spherical or ellipsoidal distributed in a cellular or continuous chain-like form. With the reduction of sulfur content, hot-rolled coils heated at 1 230 ℃ contain more TiC precipitates with size of 10-20 nm, which can be retained after annealing in galvanizing, while TiC particles are rarely found in hot-rolled or galvanized coils at higher sulfur content. That is, more coarse Ti4C2S2 can be precipitated at higher sulfur content while the precipitation and growth of fine TiC is inhibited. The {111} surface texture ratio of galvanized coil with higher sulfur content reached more than 87.5%, therefore it′s exhibiting higher plastic strain ratio in terms of mechanical properties.
韩赟, 邱木生, 邹英, 王刚. 高塑性应变比Ti-IF钢组织性能及析出相[J]. 钢铁, 2021, 56(3): 77-83.
HAN Yun, QIU Mu-sheng, ZOU Ying, WANG Gang. Precipitates, microstructure and properties of Ti-IF steel with high plastic strain ratio[J]. Iron and Steel, 2021, 56(3): 77-83.
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