1. Department of structure Steels,Central Iron and Steel Research Institute; The State key Laboratory of Rolling and Automation, Northeastern University 2. 钢铁研究总院 3. 鞍钢技术中心 4. 钢铁研究总院结工程用钢研究所
Abstract：High strength low alloy steel (HSLA) has excellent properties of high strength, high toughness and easy welding due to the alloy design of low carbon, low carbon equivalent and Cu aging strengthening. HSLA steel can be widely used in the construction of oil pipelines, hull structures, offshore platforms, etc. The difference of microstructures and mechanical properties of quenched and tempered HSLA steel containing Cu was studied by using two different cooling methods after rolling. Microstructure of HSLA steel under different cooling modes after rolling was characterized by OM, SEM and TEM, and its tensile properties and low temperature toughness were measured. The results show that compared with air cooling after rolling, the structure of steel after rapid cooling after rolling is refined, the effective grain size is finer, and the microstructure is inherited, so that the steel after quenching and tempering has higher strength and better low temperature toughness. Moreover, the layered fracture in impact fracture of steel is restrained after rapid cooling.
2019, Vol. 38 