车削参数对GH4079高温合金表面特征的影响研究

Influence of turning parameters on the surface characteristics of GH4079 high temperature alloy

研究车削参数对GH4079高温合金表面特征的影响规律,为车削加工GH4079高温合金选择合理的加工参数提供实验基础依据。采用车削速度为280~560m/min,切削深度为0.5~1.0mm,进给量为0.035~0.088mm/r的车削参数对GH4079高温合金进行车削加工,并用CALISUM表面粗糙度仪、显微硬度仪及X射线应力衍射仪对GH4079高温合金车削表面特征(表面粗糙度、表面显微硬度及表面残余应力)进行测定。GH4079高温合金车削表面粗糙度值在Ra502~Ra1 121nm范围内变化,表面显微硬度值在570.2~677.3HV范围内波动,进给方向残余应力σr(X)呈压应力状态,而垂直于进给方向残余应力σr(Y)呈拉应力状态。研究结果表明:表面粗糙度和表面显微硬度对切削速度的变化最为敏感,表面残余应力对切削深度的变化最敏感;表面粗糙度和表面显微硬度均随切削速度的增加而减小;表面残余压应力随切削深度的增大而增大,表面残余拉应力随切削深度的增大而减小。

To study the influence of turning parameters on the surface characteristics of GH4079 high temperature alloy, and to provide the experimental basis for the selection of reasonable turning parameters for GH4079 high temperature alloy. GH4079 high temperature alloy were turning with the following turning parameters ： the turning speed 280 - 560m/min, cutting depth 0.5- 1.0 mm, feed 0.035 -0.088mm/r, and the CALISUM surface roughness instrument, microhardness tester and X-ray diffraction stress were used to measure turning surface characteristics （surface roughness, surface micro hardness and surface residual stress）. The results show that GH4079 high temperature alloy turning surface roughness value changes in the Ra502 -Ral 121rim range ,the surface microhardness values fluctuate in a range of Ra570.2 -Ra677.3HV and feed direction residual stress σr（X） is compres- sive stress, and vertical to the feed direction residual stress σr（Y）is tensile stress. The surface roughness and hardness are most sensitive to the cutting speed, and the surface residual stress is most sensitive to the cutting depth;at the same time shows that the microscopic surface roughness and surface hardness increased with increasing cutting speed, with increasing depth of cut, the com- pressive surface residual stress increased and the tensile surface residual stress reduced.