【作者】 苑荣华；

【导师】 孙杰；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2010， 硕士

【摘要】 69111不锈钢(09Crl2Mn5Ni4Mo3Al)是20世纪50年代后期我国自主研发和应用起来的新型不锈钢,是由621所、625所、上钢三厂、上海钢铁研究所等单位协作研制成功的立足国内资源而基本性能优于国外近似钢种的一种不锈钢。69111不锈钢属于典型难加工材料,加之国内应用历史较短,对于其切削加工方面的研究相对较少,本研究在对69111不锈钢研究现状进行分析和总结的基础上,对69111不锈钢切削加工机理和工艺参数优化进行系统研究。(1)设计、完成了应用四种刀具铣削加工69111不锈钢正交切削实验和单因素切削实验,采用正交实验分析法对正交实验数据进行分析处理,获得能够减小铣削力的优化的参数组合,并采用幂指数非线性拟合的方法,进行了铣削力建模,建立了铣削力经验公式,实现了铣削力的理论预测；采用正交优化的参数进行了整体硬质合金刀具铣削69111不锈钢磨损寿命实验,获得整体硬质合金刀具磨损寿命曲线。(2)从表面粗糙度和残余应力两个方面对铣削加工69111不锈钢的已加工表面进行了表面完整性分析。对整体硬质合金刀具铣削加工表面的粗糙度进行正交实验分析法分析,获得铣削参数对于表面粗糙度影响程度的主次顺序,同时采用二次项拟合的方法进行表面粗糙度经验公式的非线性拟合,精度较高；残余应力分析得出铣削加工的表面残余应力大都为拉应力。对于可转位刀具加工69111不锈钢表面粗糙度对比分析得出伊斯卡可转位刀具结构不适合加工69111不锈钢；残余应力分析得出山特维克可转位刀具与其他两种可转位刀具规律不相同。工艺参数对于表面粗糙度影响规律为：随铣削速度、每齿进给量的增大表面粗糙度线性增大,随轴向切深的增加,表面粗糙度线性降低,随径向切深的增加呈现出曲折变化的趋势,先增大后减小而后又呈现出增大的趋势；工艺参数对于表面残余应力的影响主要通过铣削力和铣削温度间接起作用。(3)在理论分析的基础上,通过设计完成69111不锈钢不同应变率、不同温度下的动态压缩实验和准静态拉伸实验,以及不同应力三轴度下的拉伸实验,回归拟合出69111不锈钢本构关系模型和失效模型；并设计球盘摩擦实验,建立摩擦系数与压力、滑动速度之间的关系,从而获得切削加工过程中刀屑摩擦性能。(4)在前面研究的基础上,对69111不锈钢的铣削工艺参数进行优化。采用有限元仿真模拟的方法,对铣削加工69111不锈钢用可转位刀具进行刀具几何结构参数优化,获得优化的前角、后角及钝化半径值,为刀具参数结构设计提供理论支持；后对整体硬质合金刀具进行铣削参数优化,综合考虑铣削力、表面粗糙度、以及金属去除率指标,采用正交分析法,获得综合考虑各指标下的铣削参数组合,提高了生产效率；最后对高速精加工工况进行了铣削速度的优化；通过实验分析,以铣削力和铣削温度为优化指标,获得较优的铣削速度,对于实际加工起到指导性作用。更多还原

【Abstract】 69111-stainless steel (09Cr12Mn5Ni4Mo3Al) was developed by our country in 1950s, which was developed based on the resources of our country by the research center 621, 625 and the third company of Shanghai steel company and Shanghai steel research center and etc. Its performances are better than the same style steel overseas. However, 69111-stainless steel is typically hard-to-cutting material, and its application history is very short, the research about its cutting performances is little. The research status about the 69111-stainless steel is analyzed and summarized; meawhile, the cutting mechanism and process parameters optimization are focused to describe the cutting characters of 69111- stainless steel comprehensively.(1) The orthogonal tests and the single factor experiments were designed and conducted with four different kinds of tools. The experiment data was processed by the orthogonal experiment analysis method, to describe the parameters which have less effect on the cutting forces. The cutting force model was built by nonlinear fitting method, which makes the cutting force prediction become reality in theory. Tool life and tool wear experiment of the cutting 69111- stainless steel was conducted with the optimized parameters, so that the tool life and tool wear curve of the solid carbide cutting tool can be derived.(2) The surface integrity of the milled 69111- stainless steel was analyzed by the surface roughness and the residual stress. For the solid carbide cutting tool:the milled surface roughness was investigated by the orthogonal experiment analysis method to get the sequence of the parameters which influence the surface roughness. The surface roughness empirical formula was built by quadratic term nonlinear fitting method with high precision. The tensile stress was found during most of the residual stress analysis processes. For the indexable tool:the surface roughness of the milled surface using the ISCAR tool is larger than the other two tools, so its micro-structure is not fit for milling 69111- stainless steel. The residual stress of the surface milled by the SANDVIK tool took on different characters compared with the other tools. The rules of the surface roughness influenced by the parameters are shown following:the surface roughness increase larger linearly with the increasing cutting speed and the feed, while decrease linearly with the increasing axial depth-of-cut (DoC). However, there is an inflexion with the increasing radial DoC. The characters of the surface residual stress influenced by the parameters are not obvious, because the parameters have an indirect influence on the stress through affecting the milling force and the milling temperature indirectly.(3) The constitutive model and the failure model of 69111- stainless steel were built through designing the dynamic compression test and the quasi-static tensile test under different strain rates and temperatures, the tensile test under different stress tri-axiality. The friction test was designed to get the relationship between the friction coefficient, the pressureand speed.(4) The optimization of the milling parameters was accomplished based on the former research. Firstly, the geometric structure optimization of the cutting tool was completed by FEM, and the optimized rake angel, flank angel and the radius of the cutting edge give significant support to the micro-structure design of the tool. Then the optimization of the milling parameters based on the solid carbide cutting tool was completed, considering comprehensively on the milling force, the surface roughness, and the removal rate, with the orthogonal experiment analysis method and the optimized parameters increases the production efficiency. On the other hand, the optimization of the cutting speed under the situation of high speed finishing machining was completed considering the milling force and the cutting temperature, which has a guide meaning to the practical manufacturing.更多还原