06Cr18Ni11Ti本构的建立及其窄深槽缓进磨削的试验研究

发布时间：2018-03-01 09:25

本文关键词： 06Cr18Ni11Ti不锈钢窄深槽缓进磨削本构模型表面粗糙度　出处：《太原理工大学》2016年博士论文　论文类型：学位论文

【摘要】：窄深槽是指槽的深宽比大于2,且槽宽小于4mm的一种特殊结构,常出现在航空、汽车等领域的重要零部件上。变量泵的转子圆周上一般会均布10~12个径向的高精度直槽,这类槽便是典型的窄深槽。高精度的窄深槽的加工是机械领域中的难题。当变量泵输送具有酸腐蚀性的物料时,要求转子本身具有耐腐蚀性。06Cr18Ni11Ti不锈钢不仅强度高而且韧性好,具有较强的抗晶间腐蚀能力及良好的冷热加工性能和焊接性,将其选为转子材料并在其上进行窄深槽的加工研究具有一定的理论意义和实用价值。论文从研究06Cr18Ni11Ti的动态力学性能入手,进行了材料常温下的准静态单轴压缩实验、常温和高温下的分离式霍普金森压杆实验,获得了材料的真应力-真应变曲线,建立了材料的本构模型;利用有限元分析软件ABAQUS对06Cr18Ni11Ti进行了单颗磨粒平面磨削加工仿真;使用单层电镀CBN砂轮,通过大桥MV-40型立式加工中心进行了06Cr18Ni11Ti不锈钢窄深槽的缓进磨削加工试验研究。研究工作得到国家自然科学基金项目(51575375)的资助。论文的主要内容如下:(1)研究了不锈钢及其加工技术现状;进行了窄深槽的加工技术现状分析,详细阐述了窄深槽的缓进磨削加工技术及其应用。(2)进行了准静态单轴压缩实验和常温、高温下的分离式霍普金森压杆实验;研究了06Cr18Ni11Ti的动态力学性能;基于实验数据分析提出了06Cr18Ni11Ti的修正Johnson-Cook本构模型;在0.0056s-1~2500s-1的应变率范围、20oC~300oC的变形温度范围内采用本模型对实验数据进行了拟合,拟合优度较好,R2达到0.97042,实验数据和预测数据间的平均相对误差为2.629%。(3)建立了06Cr18Ni11Ti单颗磨粒平面磨削的有限元模型(ABAQUS模型),对不同砂轮速度、不同未变形磨屑厚度和不同磨粒切刃前角条件下的磨削加工进行了仿真,获得了磨削参数变化对磨削力、等效应力及磨削区温度的影响规律。(4)设计了正交试验研究方案,利用大桥MV-40型立式加工中心进行了06Cr18Ni11Ti窄深槽的缓进磨削加工;采用极差分析和表面形貌显微图像相结合的方法对窄深槽槽壁的表面质量进行了分析,探索了磨削参数对窄深槽槽壁表面粗糙度Ra值的影响规律;确定了使用大桥MV-40型立式加工中心缓进磨削06Cr18Ni11Ti窄深槽的最优工艺参数组合;采用偏最小二乘回归法建立了窄深槽槽壁表面粗糙度Ra值的预测模型,该模型经拟合优度检验得R2为0.94656,拟合度较好;在95%的置信水平下,经方差检验得P=0.038574,回归模型整体显著。
[Abstract]:Narrow deep groove is a special structure with a ratio of depth to width of more than 2 and a slot width of less than 4 mm. It often appears on important parts in aviation, automobile and other fields. The rotor circumference of variable pump is usually distributed with 10 ~ 12 radial straight slots. Such grooves are typical narrow deep grooves. The machining of high precision narrow deep grooves is a difficult problem in the mechanical field. When variable pump conveys acid-corrosive materials, the rotor itself is required to have corrosion resistance. 06Cr18Ni11Ti stainless steel not only has high strength but also good toughness. It has strong resistance to intergranular corrosion, good cold and hot working performance and weldability. It is of certain theoretical significance and practical value to select it as the rotor material and to study the machining of narrow and deep grooves on it. In this paper, the dynamic mechanical properties of 06Cr18Ni11Ti are studied, and the quasi-static uniaxial compression experiments of the material at room temperature are carried out. In the experiment of split Hopkinson pressure bar at room temperature and high temperature, the true stress-strain curve of the material is obtained, the constitutive model of the material is established, and the plane grinding process of 06Cr18Ni11Ti is simulated by the finite element analysis software ABAQUS. Using a monolayer electroplated CBN wheel, Through the vertical machining center of MV-40 model bridge, the experimental research on the slow progressive grinding of 06Cr18Ni11Ti stainless steel with narrow and deep groove was carried out. The research work was supported by the National Natural Science Foundation of China. The main contents of this paper are as follows: 1) the stainless rust has been studied. The present situation of steel and its processing technology; The processing technology of narrow deep groove is analyzed in this paper. The grinding technology of narrow deep groove and its application are described in detail. The quasi-static uniaxial compression experiment and split Hopkinson pressure bar experiment at room temperature and high temperature are carried out. The dynamic mechanical properties of 06Cr18Ni11Ti are studied, the modified Johnson-Cook constitutive model of 06Cr18Ni11Ti is proposed based on the analysis of experimental data, and the experimental data are fitted within the strain rate range of 0.0056s-1102500s-1 and the deformation temperature range of 20oC / 300oC. The relative error between experimental data and prediction data is 2.629. The finite element model of single abrasive grain plane grinding of 06Cr18Ni11Ti has been established, and the Abaqus model has been established for different grinding wheel velocities. The grinding process with different thickness of undeformed debris and different cutting edge angle of abrasive particle is simulated, and the influence of grinding parameters on grinding force, equivalent stress and temperature of grinding zone is obtained. The grinding of 06Cr18Ni11Ti narrow deep groove was carried out by using the bridge MV-40 vertical machining center, and the surface quality of the narrow deep groove wall was analyzed by means of range analysis and surface morphology micrograph. The influence of grinding parameters on the surface roughness Ra value of narrow deep groove wall is explored, and the optimum technological parameters combination of slowly advancing grinding 06Cr18Ni11Ti narrow deep groove with MV-40 vertical machining center of bridge is determined. Using partial least square regression method, the prediction model of surface roughness Ra value of narrow deep groove wall is established. The fitting coefficient of the model is 0.94656, and the regression model is significant under the confidence level of 95%.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG580.6

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