关键词: GCr15钢, 240 mm x 240 mm连铸坯, 粗轧辊, 磨损, 数值模拟, 工艺优化

Abstract: According to the status of serious wearing of rough mill roller during 240 mm X 240 mm bloom of bearing steel GCr15 at rolling mill, the effect of stock reduction amount, roll hardness, thermal conductivity and friction factor at a time of forming pass on roll wearing rule has been simulated and analyzed by using Archard wear mathematical model. The simulated results show that the higher the hardness of roll, the stronger the roll wear resistance; the effect of thermal conductivity on wearing of roll is minor； as friction factor f＞0.25, the effect of friction factor on change of wearing of roll is obvious; as stock reduction amount △h＜50 mm , the effect of stock reduction amount on wearing of roll is also obvious. Based on obtained results, combined with rolling process in situ and material of roll, with the measures including modifying the used spheroidal graphite I roll [tensile strength≥400 MPa, HRC hardness 40, thermal conductivity 18 kW/(m²·℃ ) and friction factor/=0.3] to spheroidal graphite II roll [ tensile strength 3500 MPa, HRC hardness 45 , thermal conductivity 17 kW/(m²·℃) and friction factor/=0.2] , and decreasing the reduction amount from 70 mm to 50 mm, the rolling steel amount by single groove of roll increases from 10000 t before optimization to 18000-20000 t after optimization.

Key words: GCr15 Steel, 240 mm x240 mm Casting Bloom, Rough Mill Roller, Wearing, Numerical Simulation, Process Optimization