重载切削条件下切削变形区热—力分布特性研究

发布时间：2018-06-01 06:00

本文选题：重载切削 + 切削变形区　；参考：《哈尔滨理工大学》2017年硕士论文

【摘要】：2.25Cr-1Mo-0.25V钢在我国石油、能源行业有着非常广泛的应用,是加氢反应器筒节材料的重要组成部分,材料本身具有强度高、塑性好、耐高温等优点,是一种难加工材料。在重型切削中,切削深度和进给量大,导致产生的切削温度和切削力也非常大,在热-力的共同作用下会对刀具磨损产生一定的影响,因此,对重载切削条件下切削变形区的热-力分布情况进行研究,掌握其分布规律,以解决加工效率低、刀具磨损严重等难题。首先,基于前刀面切削力系数建立前刀面切削力预测模型,通过试验来验证模型的精确性;研究大型切屑的卷曲过程,揭示切屑的生成机理;分析重载条件下切屑的折断力学特性,为大型切屑的卷曲和折断研究提供理论参考。其次,对重型切削变形区的温度场进行研究,推导出剪切区和刀-屑接触区温度的计算公式;通过刀具磨损试验并借助有限元仿真技术,对切削温度与刀具磨损的关系进行定量分析,建立刀具前刀面磨损模型。再次,进行切削试验,测量切削温度、切削力并收集不同参数下的切屑,为切削力模型的预测提供试验数据;磨制硬质合金棒进行高温拉伸试验,研究刀具材料的高温力学特性。最后,建立车削2.25Cr1-Mo-0.25V钢的有限元仿真模型,对不同切削参数下的切削力、切削温度和应力分布情况进行研究,进而验证切削力模型的有效性;进行正交试验,优选出最佳切削用量。
[Abstract]:2.25Cr-1Mo-0.25V steel is widely used in petroleum and energy industry in China. It is an important part of hydrogenation reactor tube material. The material itself has the advantages of high strength, good plasticity and high temperature resistance, so it is a difficult material to process. In heavy-duty cutting, the cutting depth and feed rate are large, and the cutting temperature and cutting force are also very large. Under the combined action of heat-force, the tool wear will be affected to a certain extent. In order to solve the problems of low machining efficiency and serious tool wear, the thermo-force distribution in the cutting deformation area under heavy load cutting is studied and its distribution law is grasped. Firstly, based on the cutting force coefficient of the front cutting face, the prediction model of the cutting force on the front cutting face is established, and the accuracy of the model is verified by experiments, and the crimp process of the large chip is studied to reveal the mechanism of chip formation. The mechanical properties of chip breaking under heavy load are analyzed, which provides a theoretical reference for the study of large chip crimp and fracture. Secondly, the temperature field in the deformation region of heavy duty cutting is studied, and the formulas for calculating the temperature of shear zone and cutter chip contact zone are derived, and the cutting tool wear test and finite element simulation technology are used to calculate the temperature of the shear zone and the contact zone of cutter and chip. The relationship between cutting temperature and tool wear was quantitatively analyzed, and a tool front wear model was established. Thirdly, cutting test, measuring cutting temperature, cutting force and collecting chip under different parameters provide test data for prediction of cutting force model. The high temperature mechanical properties of cutting tool materials are studied. Finally, the finite element simulation model of turning 2.25Cr1-Mo-0.25V steel is established, the cutting force, cutting temperature and stress distribution under different cutting parameters are studied, and the validity of the cutting force model is verified. Select the best cutting parameters.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG501

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