Ti150合金离心叶轮锻件工艺优化

目的 解决Ti150合金离心叶轮锻件低倍组织不均匀和锻件力学性能离散性较大的问题。方法 通过对锻件进行金相组织分析，再利用EBSD、DEFORM等工具分析锻件成形时应变分布及组织特点，探索低倍组织不均匀和锻件力学性能离散性较大的原因及解决方法。通过对棒材进行六方拔长、倒棱、平头和滚圆等处理，实现从圆棒到六方形再到圆棒的变形过程(改锻)，使棒材各部位的变形均匀，达到消除微织构的目的。结果 对棒材进行反复镦拔(改锻)，可有效消除棒材中的微织构并改善低倍组织的不均匀，是控制锻件力学性能离散性的重要措施。结论 中间坯组织的均匀性是影响低倍组织不均匀和锻件力学性能离散性的主要因素，通过对棒材进行改锻，Ti150合金离心叶轮锻件的组织及力学性能优异，满足相应的技术要求。

Process Optimization of the Ti150 Alloy Centrifugal Impeller Forging

The paper aims to resolve the macrostructure nonuniformity under low magnification and high discreteness of the mechanical property for Ti150 alloy centrifugal impeller forging. The metallographic image analysis, electron backscatter diffraction (EBSD) and Numerical simulation software (DEFORM) were used to analyze the strain distribution and the microstructure characteristics of the forging, so that the reasons and solutions of the macrostructure nonuniformity under low magnification and high discreteness of the mechanical property were explored. The deformation process (substituting forging) from round bar, hexagonal bar, to round bar was realized by means of hexagonal drawing, chamfering, flat head and rolling, which were repeated three times to make deformation of each part of the bar uniform and eliminate its microtexture. The results showed that the microtexture was eliminated, macrostructure nonuniformity under low magnification was improved, and the integral microstructure uniformity was increased, which proved that the substituting forging for the bar is an important method to control the high discreteness of the mechanical property of the forging. The microstructure uniformity of the intermediate billet is the main factor on the macrostructure nonuniformity under low magnification and high discreteness of the mechanical property. By adopting the substituting forging for the bar, the Ti150 alloy centrifugal impeller forging can be produced with excellent microstructure and mechanical properties, which can meet corresponding technical requirements.