IN690高温合金管材热挤压工艺及组织演变规律研究

发布时间：2018-01-08 06:22

本文关键词：IN690高温合金管材热挤压工艺及组织演变规律研究　出处：《沈阳理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：高温合金Inconel690(IN690)具有优异的抗腐蚀开裂能力、高强度、良好的冶金稳定性和优良的加工特性等优点,广泛应用于蒸汽发动机、压水反应堆中。本文采用DEFORM-3D模拟软件、元胞自动机法(CA法)以及先进实验测试方法等对高温合金IN690管材挤压变形过程进行研究。主要研究成果与结论如下:(1)通过有限元分析软件DEFORM-3D中的模具应力分析模块,研究了不同挤压工艺参数下挤压模具的温度场和应力场。降低坯料温度,增大速度,减小摩擦系数,模具最终温度降低;升高坯料温度,增大挤压速度,减小摩擦系数和挤压比,模具最大主应力值减小;(2)利用DEFORM-3D对高温合金IN690管材进行多场耦合模拟,分析了不同参数下管材的温度场、应力场、应变场和挤压力的分布规律。得到了不同挤压工艺参数对挤压变形过程的影响规律;(3)对高温合金IN690管材挤压时的动态再结晶进行了模拟研究,获得了不同挤压工艺条件下动态再结晶与平均晶粒尺寸的变化规律,即:升高管坯温度,完全动态再结晶区域变大,平均晶粒尺寸变大;升高挤压速度,完全动态再结晶区域变大,但相差不大,平均晶粒尺寸减小;增大挤压比,完全动态再结晶区域变大,平均晶粒尺寸减小;管材壁厚方向上由内壁向外平均晶粒尺寸呈现先增大后减小的规律;(4)采用元胞自动机(CA)方法对高温合金IN690管材挤压变形过程中动态再结晶组织演变规律进行了数值模拟研究。确定了位错密度模型、回复模型、形核模型、晶粒长大模型等。分析了挤压变形过程中动态再结晶的过程,得到了变形过程中的晶粒形态、分布、取向和尺寸;(5)完成了高温合金IN690管材挤压实验,分析了管材组织性能。模拟结果与实验结果相吻合,平均晶粒尺寸的数值模拟结果与实验结果的相对误差小于15.97%。
[Abstract]:High temperature alloy Inconel690 (IN690) has excellent anti cracking ability, high strength, good metallurgical stability and excellent processing characteristics, widely used in steam engines, in a pressurized water reactor. This paper uses the DEFORM-3D simulation software, cellular automaton method (CA method) and the advanced experimental testing method of extrusion deformation the process of high temperature alloy IN690 tubing. The main research results and conclusions are as follows: (1) through the die in the finite element analysis software DEFORM-3D stress analysis module of extrusion die with temperature field and stress field of different extrusion parameters. To reduce the billet temperature, increase speed, reduce the friction coefficient, the final mold temperature decrease increased; the billet temperature, increase of extrusion speed, friction coefficient and extrusion ratio, the maximum principal stress value of mold decreases; (2) using DEFORM-3D high temperature alloy IN690 pipe coupling Simulation analysis of temperature field under different parameters of material, stress field, strain field distribution of extrusion pressure and the different extrusion. Influences of process parameters on the extrusion process; (3) on the dynamic IN690 alloy tube extrusion during recrystallization were simulated research, obtained recrystallization change the law, and the average grain size of the different dynamic extrusion process conditions: the increase of billet temperature, fully dynamic recrystallization zone becomes larger, the average grain size increases; extrusion speed, fully dynamic recrystallization zone becomes larger, but the difference is not large, the average grain size decreases; the increase of extrusion ratio, completely dynamic recrystallization area becomes larger, the average grain size decreases; tube wall thickness direction from the inner wall to the outside the average grain size increases first and then decreases; (4) using cellular automaton (CA) method for IN690 alloy tube extrusion deformation The dynamic recrystallization evolution process was simulated. The dislocation density model, response model, nucleation model, grain growth model. The deformation dynamic recrystallization in the process of analysis, the grain shape, the deformation process of the distribution, size and orientation; (5) completed IN690 high temperature alloy tube extrusion experiment, microstructure properties were analyzed. The simulation results agree well with the experimental results, the relative error of numerical simulation results with experimental results the average grain size of less than 15.97%.

【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG376.2;TG132.3

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