Development of segment hot charging pretreatment process of thick slab
Hot delivery and hot charging technology can significantly reduce energy consumption of heating furnaces,improve production efficiency,and reduce carbon emissions during steelmaking and rolling process.However,hot delivery cracks are easily existed on the plate surface after high temperature hot delivery of microalloyed steel slabs,which limits the application of this technology.In this work,the high temperature tensile test experiment was car-ried out to investigate the reasonable cooling rate during the hot charging pretreatment process of 300 mm slab.The variation process of surface temperature and microstructure of slab during the hot charging pretreatment process was studied through industrial experiments.The surface quality and mechanical properties of steel plates with hot char-ging pretreatment process were studied using statistical methods.The results indicate that the surface temperature of 300 mm thick slab is deceased from 920 ℃ to 387 ℃,and the cooling rate is about 4.2 ℃/s during the segment hot charging pretreatment process.The surface temperature is return to 742 ℃,and the heating rate is about 1.2 ℃/s.Fine bainite structures are formed through rapid cooling and reheating on the surface of the slab.After the implementation of the hot charging pre-treatment process,the hot charging temperature of the slab is increased from 500-550 ℃ to 600-650 ℃,and the hot delivery cracks are eliminated,and the mechanical properties of the steel plate are stable.
hot charging and deliveryhot delivery crackshot charging pretreatmentcontinuous castingthick slab
万方数据
维普
