齿轮钢18Cr2Ni4WA磨削烧伤实验及仿真预测研究

18Cr2Ni4WA钢以其韧性好和强度高的特点,广泛使用于螺旋伞齿轮等重载齿轮的生产与制造。磨齿作为齿轮加工的最后工序,磨削区域较高温度场容易引起磨削烧伤发生,使加工表面质量和疲劳寿命难以保证。针对齿轮钢18Cr2Ni4WA磨削烧伤问题,设计SG砂轮磨削实验,研究其发生磨削烧伤时表面形貌、显微硬度的变化规律,并通过有限元仿真预测烧伤层深。研究结果表明:当砂轮速度为20.3m/s、工件速度为0.03m/s、磨削深度大于0.05mm时工件发生磨削烧伤,随着磨削深度的增加,烧伤程度加重,磨削表面氧化层颜色由淡黄色转为褐色最后呈现青色,表面形貌由纹理清晰转为涂覆;工件产生回火烧伤时,产生硬度较低的回火索氏体;烧伤层深的仿真模拟值与实验测量值基本吻合,验证了有限元仿真对磨削烧伤预测的可行性。

Experiment and Simulation Prediction of Grinding Burn of Gear Steel 18Cr2Ni4WA

18Cr2Ni4WA steel has been widely used to manufacture the heavy-duty gears,such as spiral bevel gear,which is characterized by high toughness and high strength.Grinding burn easily occurs due to the high temperature during grinding,which makes the grinding precision and surface quality difficult to meet the requirements.The surface hardness,hardness gradient and surface morphology of workpiece are analyzed through single factor experiment,and the degree of grinding burn is simulated using the finite element analysis software.The results show that,with the increase in grinding depth,the degree of grinding burn is aggravated,the color of oxide layer is changed from faint yellow to brown,and finally becomes cyan,and the surface morphology is changed from clear texture to heavily coated.The hardness of surface layer decreases and a tempered sorbite is produced due to tempering burn.The measured and simulated values of grinding burn depth are basically identical,which shows that the degree of grinding burn can be predicted by the finite element simulation.