数值模拟技术在汽轮机叶片模锻成形中的应用

Application of numeric simulating technology in hot die forging turbine blade

有许多因素影响汽轮机叶片的模锻生产质量,例如,材料性质、毛坯外形及尺寸、模锻方式及工艺、模腔结构与锻压设备等。本文针对某汽轮机叶片的模锻生产,应用数值模拟技术,分析和探讨了改进模锻工艺、提高产品质量、防止模具过早失效的途径。模拟结果与生产实践表明:在保证坯料金属完全充满模腔并压实的前提下,适当减少锤击次数,既能降低模具损坏几率,又可节约锻打能源;尽量采用较大的过渡圆角半径,以便抑制模锻叶片根部折叠等缺陷的产生;界面润滑有利于模锻叶片成形;模具型腔局部高温和高应力的交互作用是造成模具过早失效的重要原因。

There are many factors influencing hot die forging quality of turbine blade, such as material property, billet outline and size, die forging method and plan, die cavity structure and drop forging equipment, etc. Taking an example of a blade＇s hot die forging process, the ways of improving forging plan, enhancing work-piece quality and preventing die premature failure were analyzed and discussed by means of numeric simulating experiment. The experiment resuits and production practices proves that the number of blows is properly reduced may decrease the probability of die failure and save forging energy in the preconditions to ensure the die cavity being completely filled by billet and the high-quality work-piece being produced. Making the full of the larger fillet radii may avoid the transitional region between the root block and the work section from forging defects, such as lap and so on. Lubricating the interface of billet and die is propitious to blade forging process. High-temperature and high-stress acting reciprocally on the local region of die cavity is one of the important reasons causing the die premature failure.