1. Jiangsu Shagang Group Co., Ltd., Zhangjiagang 215625, Jiangsu, China; 2. Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu, China
Abstract：In order to study the effect of Ti on tensile and impact properties of hot rolled steel sheet, rolling test of Ti-containing microalloyed steel with different composition systems was carried out by different rolling processes with hot rolling test set. The microstructure and mechanical properties of the test steels were characterized and tested by OM, SEM, tensile and impact tests. The results show that adding a certain amount of Ti to the low carbon steel can significantly improve the strength of steel, but at the same time, the impact toughness of the steel will be significantly reduced. The large particles of TiN and coarse ferrite grains precipitated in the steel are the main factors leading to the deterioration of impact toughness for Ti-containing microalloyed steel. By adding Nb to Ti-containing microalloyed steel, adopting Ti-Nb composite strengthening, and combining 840 ℃ low-temperature finishing rolling and 560 ℃ low-temperature coiling process, the impact toughness of Ti-containing microalloyed steel can be significantly improved, and the comprehensive properties of high strength and high toughness can be obtained.
2023, Vol. 33 
