雾化气体淬火过程应力场的数值模拟及实验研究

发布时间：2018-01-24 20:51

本文关键词： 雾化气体淬火数值模拟热应力场换热系数残余应力　出处：《昆明理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：雾化气体冷却技术早在很多年前就开始应用于工业生产,并取得一系列的突破和创新。雾化气体淬火有足够的淬火能力,保证了工件以大于临界淬火冷却速度冷却,冷却能力较好。同时,雾化气体作为一种新型的淬火介质,具有可控性强、冷却均匀以及无污染等特点,越来越受到人们的关注。但是,由于雾化气体淬火起步较晚,目前还处于实验探索阶段。对于淬火设备的开发和淬火结果的测试都还具有一定的困难。本文通过计算机数值模拟和实验结果相结合的研究方法,主要研究了雾化气体淬火时的热应力场以及淬火冷却后的残余应力。首先,根据热弹塑性理论和相关理论对试件的增量型应力-应变关系进行了分析,并研究了雾化气体淬火热应力场的定解条件,淬火热应力场的非线性问题以及边界条件的分析。然后运用ANSYS有限元分析软件建立了淬火的试件的数学模型和网格模型,将表面综合换热系数和气体压力代入边界条件对淬火的热应力场进行数值模拟计算,并对热应力场和残余应力进行分析。最后,本文设计了钻孔法测量残余应力的实验,对雾化气体淬火冷却后试件的残余应力进行测量并采集实验数据,将数值模拟计算结果和实验数据进行对比分析,对比结果表明本文对雾化气体淬火时热应力场的数值模拟是有效的。
[Abstract]:Atomized gas cooling technology has been used in industrial production for many years, and has made a series of breakthroughs and innovations. Atomized gas quenching has sufficient quenching ability. At the same time, as a new quenching medium, atomization gas has the characteristics of strong controllability, uniform cooling and no pollution. More and more people pay attention to it. However, the atomization gas quenching starts late. At present, it is still in the stage of experimental exploration. There are still some difficulties for the development of quenching equipment and the testing of quenching results. This paper combines the computer numerical simulation with experimental results. The thermal stress field of atomized gas quenching and the residual stress after quenching and cooling are mainly studied. Firstly, the incremental stress-strain relationship is analyzed according to thermoelastic-plastic theory and related theory. The conditions for determining the thermal stress field of atomized gas quenching are also studied. The nonlinear problem of quenching thermal stress field and the analysis of boundary conditions are analyzed. Then the mathematical model and mesh model of quenched specimen are established by using ANSYS finite element analysis software. The surface comprehensive heat transfer coefficient and gas pressure are added to the boundary conditions to simulate the thermal stress field of quenching, and the thermal stress field and residual stress are analyzed. In this paper, the experiment of measuring residual stress by borehole method is designed. The residual stress of the sample after atomization gas quenching is measured and the experimental data are collected. The numerical simulation results are compared with the experimental data. The results show that the numerical simulation of thermal stress field in atomized gas quenching is effective.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG156.3

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