基于Deform的GCr15钢通电加热硬切削模拟仿真

发布时间：2018-10-25 11:31

【摘要】：随着现代工业技术的发展和产品零部件性能要求的提高,许多新型的难加工材料被研究者发现并生产了出来,因为新型的难加工材料具有较高的硬度,致使切削时较大的切削力,较高加工区域内温度的产生,这些问题导致了切削刀具的磨损情况加重,刀具使用寿命降低,且加工后的工件表面质量不高,切削效率低,因此采用新的切削加工方法,提出降低硬切削刀具磨损和提高工件质量的绿色制造新方法和理论,通过仿真实验揭示切削参数对切削过程的影响,确定通电加热切削的关键因素—切削电流,提出新的主切削力经验公式,有非常重要的学术价值和工程意义。本文基于Deform研究了(通电加热切削条件下)刀具前角φ、切削速度V、进给量f、工件初始温度T等对主切削力、接触区温度、刀具磨损量的影响,确定了YT726切削GCr15的最佳电流以及主切削力的经验公式。剖析了通电加热切削降低工件切削难度的原理,通过对加热电阻的分析,对比已经存在的加热电阻模型,选择了一种较优的电阻模型作为本课题的加热电阻模型。除此外本课题还详细介绍了材料的本构模型、磨损模型、摩擦模型等相关理论知识,并根据实际情况选择了仿真所需的相关模型及参数。经过仿真试验研究,论文得出了如下主要结论:(1)增大刀具前角、切削速度、工件初始温度,主切削力反而降低;增加进给量,主切削力也逐渐增加。主要原因是刀具前角增加工件切削层的塑性变形减弱,接触区的摩擦力降低;切削区温度的增加,降低了加工区的强度,主切削力降低。(2)切削区温度随切削速度、进给量、工件初始温度的升高而升高,随刀具前角的增大而降低,最大的原因是刀具前角度数的增加,产生的切屑变形减弱,同时切削热减少,所以切削区的温度降低;随着切削速度的增加,导致切削过程中产生的热不能及时的随切屑带走,而且切削热来不及向刀具传递,因而切削温度升高。(3)刀具磨损随刀具前角、切削速度、进给量的增加也逐渐加大,随工件初始温度升高而减少,最大原因是过高的温度导致强度较高的刀具材料中的钴元素流失,而工件材料中的铁、碳元素向刀具材料扩散,降低了刀具材料的强度,加剧刀具磨损情况。(4)本文通过分析加热电流对主切削力、切削温度、刀具磨损量的影响,确定了YT726切削GCr15的最佳电流范围为110-130A。(5)采用正交仿真实验,通过SPSS统计软件开展多元非线性回归分析,得到了YT726切削GCr15的主切削力经验公式。
[Abstract]:With the development of modern industrial technology and the improvement of the performance requirements of product parts, many new types of hard-to-process materials have been discovered and produced by researchers, because the new hard-to-process materials have higher hardness. As a result of the larger cutting force and the higher temperature in the machining area, the wear of the cutting tool is aggravated, the service life of the cutting tool is reduced, and the surface quality of the workpiece is not high and the cutting efficiency is low. Therefore, a new green manufacturing method and theory to reduce the wear of hard cutting tools and improve the quality of workpiece are put forward by using a new cutting method, and the influence of cutting parameters on the cutting process is revealed by simulation experiments. It is of great academic value and engineering significance to determine the key factor of electrically heated cutting-cutting current and to put forward a new empirical formula of main cutting force. Based on Deform, the effects of cutting tool front angle 蠁, cutting speed V, feed rate f, workpiece initial temperature T on the main cutting force, contact zone temperature and tool wear are studied. The optimum current and the empirical formula of the main cutting force for YT726 cutting GCr15 are determined. This paper analyzes the principle of electric heating cutting to reduce the cutting difficulty of workpiece. Through the analysis of heating resistance and comparing the existing heating resistance model, a better resistance model is selected as the heating resistance model of this subject. In addition, the related theories of constitutive model, wear model and friction model are introduced in detail, and the relevant models and parameters for simulation are selected according to the actual situation. The main conclusions are as follows: (1) increasing the cutting speed, the initial temperature of the workpiece and the main cutting force decrease, and the main cutting force increases with the increase of feed rate. The main reasons are that the plastic deformation of the cutting layer decreases and the friction in the contact area decreases with the increase of the cutting front angle, and the strength of the machining zone decreases with the increase of the temperature in the cutting zone. (2) the temperature of the cutting zone decreases with the cutting speed and the feed rate. The increase of the initial temperature of the workpiece decreases with the increase of the front angle of the cutting tool. The biggest reason is that the chip deformation decreases and the cutting heat decreases with the increase of the number of the front angles of the cutting tool, so the temperature of the cutting zone decreases. With the increase of cutting speed, the heat produced in cutting process can not be taken away with chip in time, and the cutting heat can not be transferred to the tool, so the cutting temperature increases. (3) the tool wear increases with the cutting tool front angle and cutting speed. The increase of feed rate gradually increases and decreases with the increase of the initial temperature of the workpiece. The biggest reason is that the high temperature causes the loss of cobalt element in the high strength cutting tool material, while the iron and carbon elements in the workpiece material diffuse to the tool material. (4) by analyzing the influence of heating current on the main cutting force, cutting temperature and tool wear, the optimum current range of YT726 cutting GCr15 is determined to be 110-130 A. (5) orthogonal simulation experiment is used. The empirical formula of the main cutting force of YT726 cutting GCr15 is obtained by multivariate nonlinear regression analysis with SPSS statistical software.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG506

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