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采用理论推导、数值仿真法和实验手段相结合的方法,首先以SG砂轮对20CrMnTi弧齿锥齿轮的成形磨削建立了温度场的有限元模型,选用了矩形分布热源的移动加载方法并用ANSYS软件进行了温度场的仿真分析,发现不同磨削参数对磨削温度场的影响规律,即随着径向进给量的增大,工件磨削区表面温度升高;砂轮速度越高,磨削温度升高;随着展成速度的增大,磨削温度呈现先减少后增加的趋势。然后观察弧齿锥齿轮大轮烧伤区的金相组织,检查齿部截面硬度梯度。发现当工件磨削表面出现轻微烧伤时,表面组织出现了屈氏体;当出现中度烧伤时,最外表面为二次淬火马氏体,下层为回火马氏体或索氏体;严重时,表面组织有索氏体。最后发现当齿轮发生轻微烧伤时,表面显微硬度明显低于磨削前的硬度,此时变质层深度大于0.2mm;严重烧伤时,表面发生了退火烧伤,表面显微硬度下降较多,变质层深度增大,且烧伤越严重,表面显微硬度下降越多。得出:当变质层深度大于0.2mm时,产生不同程度的磨削烧伤。
Using the method of theoretical derivation, numerical simulation and experimental methods, the finite element model of temperature field was established by using SG grinding wheel for forming grinding of 20CrMnTi spiral bevel gear. The moving load method of rectangle distributed heat source was selected and the software ANSYS The simulation analysis of the temperature field shows that the influence law of different grinding parameters on the grinding temperature field is that the surface temperature of the workpiece grinding zone increases with the increase of the radial feedrate. The higher the grinding wheel speed, The temperature increases; with the increase of the exhibition speed, the grinding temperature tends to decrease and then increase. Then observe the spiral bevel gear big round burned area of the microstructure, check the tooth section hardness gradient. It is found that when there is slight burns on the surface of workpiece, troostite appears on the surface of the workpiece. When there is moderate burns, the outermost surface is secondary quenched martensite and the lower layer is tempered martensite or sorbite. When the surface organization sorbite. Finally, it was found that the surface microhardness was significantly lower than the hardness before grinding when the gear was slightly burned, and the depth of the metamorphic layer was more than 0.2mm. In the case of severe burn, the surface was annealed and burned, the surface microhardness decreased more, Layer depth increases, and the more severe burn, the more the surface microhardness decline. It is concluded that when the depth of the metamorphic layer is more than 0.2mm, different levels of burn burns occur.