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

摘要： 针对轧钢厂GCr15轴承钢240 mm × 240 mm方坯粗轧阶段轧辊磨损较严重的情况,采用Archard磨损数学模型模拟分析了轧件压下量、轧辊硬度、热传导系数及摩擦因子在一道次成形后对轧辊磨损规律的影响。模拟结果表明,轧辊硬度越高,轧辊抗磨损能力越强;热传导系数对轧辊磨损的影响较小;当摩擦因子f＞0.25时,其摩擦因子对轧辊磨损量变化明显;当轧件压下量在△h＜50 mm 时,轧件压下量对轧辊的磨损量影响显著。根据所得结果,结合现场轧制工艺和轧辊材质,将使用的球墨铸铁Ⅰ轧辊[抗拉强度≥400 MPa,硬度HRC值40,热传导系数18 kW/（m²·℃）,摩擦因子0.3]改成球墨铸铁Ⅱ轧辊[抗拉强度≥500 MPa,硬度HRC值45,热传导系数17kW,/（m²·℃）,摩擦因子0.2],并将压下量由70 mm降至50 mm,使轧辊单槽过钢量由优化前10000 t提高至优化后的18000~20000 t。

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