Effects of finish rolling temperature on microstructure and properties of low alloy Q355B steel plate with Ti
CHEN Jian-chao1, PANG Hong-xuan1, WEN Chao2, ZHAO Bo-tao2
1. Technology Center, Hebei Puyang Iron and Steel Co., Ltd., Handan 056305, Hebei, China; 2. Medium Plate Factory, Hebei Puyang Iron and Steel Co., Ltd., Handan 056305, Hebei, China
Abstract：Taking the Ti-microalloyed 355 MPa grade low-alloy high-strength steel as the research object, the test steels were subjected to finish rolling at 830, 800, 750, and 700 ℃ respectively, and the effects of finish rolling temperature on the microstructure and mechanical properties were studied. The results show that,as the finish rolling temperature decreases, the yield strength and tensile strength show an increasing trend, and the elongation and impact properties show a trend of first increasing and then decreasing. Finish rolling near Ar3temperature, the steel plate can obtain the best comprehensive mechanical properties. The matrix structure of Q355B steel sheet at different finish rolling temperatures is ferrite + pearlite. The grains of finish rolled steel plate at 800 ℃. are the most uniform and fine, and the grains of finish rolled steel plate at 830 ℃ are relatively coarser than those of finish rolled at 800 ℃. Mixed crystals appear in the microstructure of finish rolled steel plate at 750 ℃, during the finish rolling at 700 ℃, the grains of steel plate have been elongated and deformed, and "fibrous ferrite" appears to a certain extent. Fully refined grains can reduce the band structure in the steel plate.
陈建超, 庞洪轩, 温超, 赵波涛. 终轧温度对加Ti低合金Q355B钢板组织性能的影响[J]. 中国冶金, 2021, 31(10): 30-33.
CHEN Jian-chao, PANG Hong-xuan, WEN Chao, ZHAO Bo-tao. Effects of finish rolling temperature on microstructure and properties of low alloy Q355B steel plate with Ti[J]. China Metallurgy, 2021, 31(10): 30-33.
2021, Vol. 31 
