Inconel 718合金δ相溶解行为及数值模拟研究
发布时间：2019-01-11 13:01
【摘要】：本文研究了经δ相时效处理(DP)后的Inconel 718合金中δ相在不同热处理制度时的溶解行为,利用光学显微镜分析了不同温度和保温时间下δ相含量和晶粒尺寸变化,获得了δ相在静态溶解过程中的演变规律：采取硬度测试方法表征了溶解过程中δ相含量变化与其硬度数值之间的相互规律；使用Deform数值模拟软件预测了静态溶解过程中合金晶粒尺寸的变化规律,进而与实际实验结果相对比,可为Inconel 718 DP工艺的制定提供理论依据。研究结果表明,DP处理的Inconel 718合金在热处理过程中针状δ相在溶解过程中的形貌特征变化可分为两个阶段,初期的变化主要表现为长针状δ相溶解成为短针状乃至球状,后期的溶解过程主要是短针状δ相溶解成球状及部分球状δ相尺寸的减小。不同的热处理温度下,随着保温时间的延长,δ相的溶解量与保温时间的关系由溶解初期的线性关系变为溶解后的近似抛物线关系,溶解速度逐渐降低；在950℃、980℃和1000℃时,δ相的溶解量在保温一段时间后达到稳定值,而在温度为1020℃和1060℃时,δ相可持续溶解,最终完全溶解；溶解初期δ相体积分数的迅速降低是界面反应起主要作用,溶解后期主要是受扩散过程控制。δ相溶解过程中Inconel 718合金硬度测试结果表明,在同一温度下,随着保温时间的延长,合金的硬度值不断的降低；在相同保温时间下,热处理温度越高,合金的硬度越低。在溶解初期,合金硬度值下降的比较快,溶解后期合金硬度慢慢的趋于一个稳定值；DP处理工艺相比固溶处理工艺,通过增加合金中6相的含量来提高合金的硬度。DP处理Inconel 718合金δ相溶解过程中晶粒尺寸变化规律及数值模拟结果表明,当保温时间一定时,随着热处理温度的升高,晶粒尺寸长大越明显；当保温温度一定时,随着保温时间的延长,晶粒快速的长大,晶粒长大成抛物线规律变化,平均晶粒尺寸明显增加,随着保温时间的继续增长,晶粒长大的速度变慢,依据试验统计数据,建立了δ相时效态Inconel 718合金热处理过程晶粒尺寸长大模型；δ相溶解过程中晶粒尺寸预测结果与实验结果最大误差为4.2%,说明所建立的模型能够较好地用于描述Inconel 718合金DP处理后δ相溶解过程中的平均晶粒尺寸变化规律。
[Abstract]:In this paper, the dissolution behavior of 未 phase in Inconel 718 alloy treated with 未 phase aging under different heat treatment conditions was studied. The changes of 未 phase content and grain size at different temperature and holding time were analyzed by optical microscope. The evolution law of 未 phase in the static dissolution process is obtained. The mutual law between the content change of 未 phase and its hardness value during the dissolution process is characterized by hardness test method. Deform numerical simulation software was used to predict the grain size change of the alloy during static dissolution. Compared with the experimental results, it can provide a theoretical basis for the formulation of Inconel 718 DP process. The results show that the morphology of needle-like 未 phase in Inconel 718 alloy treated with DP during heat treatment can be divided into two stages. The main changes in initial stage are that the long needle-like 未 phase dissolves into short acicular phase and even globular phase. The dissolution process in the later stage is mainly due to the reduction of the size of the spherical and partial spherical 未 phases in the short needle-like 未 phase. At different heat treatment temperatures, with the prolongation of the holding time, the relationship between the dissolution amount of 未 phase and the holding time changes from the linear relationship at the initial stage of dissolution to the approximate parabola relationship after dissolution, and the dissolution rate decreases gradually. At 950 鈩，
本文编号：2407166
[Abstract]:In this paper, the dissolution behavior of 未 phase in Inconel 718 alloy treated with 未 phase aging under different heat treatment conditions was studied. The changes of 未 phase content and grain size at different temperature and holding time were analyzed by optical microscope. The evolution law of 未 phase in the static dissolution process is obtained. The mutual law between the content change of 未 phase and its hardness value during the dissolution process is characterized by hardness test method. Deform numerical simulation software was used to predict the grain size change of the alloy during static dissolution. Compared with the experimental results, it can provide a theoretical basis for the formulation of Inconel 718 DP process. The results show that the morphology of needle-like 未 phase in Inconel 718 alloy treated with DP during heat treatment can be divided into two stages. The main changes in initial stage are that the long needle-like 未 phase dissolves into short acicular phase and even globular phase. The dissolution process in the later stage is mainly due to the reduction of the size of the spherical and partial spherical 未 phases in the short needle-like 未 phase. At different heat treatment temperatures, with the prolongation of the holding time, the relationship between the dissolution amount of 未 phase and the holding time changes from the linear relationship at the initial stage of dissolution to the approximate parabola relationship after dissolution, and the dissolution rate decreases gradually. At 950 鈩，
本文编号：2407166
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