G20CrNi2MoA轴承钢控轧控冷工艺热模拟研究

控轧控冷是先进轴承钢的重要生产工艺。利用Gleeble3500热模拟试验机对G20CrNi2MoA轴承钢进行了控制轧制和控制冷却的热模拟试验，分析了变形温度、变形程度和冷却速率对G20CrNi2MoA优质滚动轴承钢微观组织和硬度的影响。基于试验结果，确定了开轧温度900 ℃、变形量30%的条件进行轧制，终轧后以5 ℃/s的冷却速率冷却到650 ℃，再以2 ℃/s的冷却速率冷却至室温的控轧控冷工艺。该工艺可获得比原始组织更细小均匀的贝氏体组织，试验钢综合力学性能有所提高，抗拉强度提升180 MPa、屈服强度变化较小、硬度提升50HV，断后伸长率提升2%。

Thermal simulation study on controlled rolling and controlled cooling process for G20CrNi2MoA bearing steel

Controlled rolling and controlled cooling is an important production process for advanced bearing steel.The thermal simulation test of controlled rolling and controlled cooling was carried out by Gleeble 3500 thermal simulation test machine.The influence of deformation temperature,deformation reduction and cooling rate on microstructure and Vickers hardness of G20CrNi2MoA high quality rolling bearing steel was analyzed.Based on the tested results,The processes were determined that the started rolling temperature was 900 ℃ and the deformation reduction was 30%.After rolling,the cooling was controlled to 650 ℃ at a cooling rate of 5 ℃/s,then was cooled to room temperature at a cooling rate of 2 ℃/s.The finer and more uniform bainite structure than the original structure was obtained by this controlled rolling and controlled cooling process,and the mechanical properties were improved.The tensile strength was increased by 180 MPa,the yield strength changes little,the hardness is increased by 50HV,and the elongation increased by 2%.