汽轮机叶片材料高温变形行为及模锻参数优化

采用试验与数值模拟相结合的方法对300MW汽轮机某级动叶片材料高温变形行为及模锻参数优化进行了研究。对1Cr12Ni2W1Mo1V合金进行的高温热模拟试验表明,该材料高温压缩下的流变应力符合双曲正弦函数关系。建立了该材料的高温本构方程,充实了不锈钢的高温材料性能库;应用所建立的材料本构方程,对叶片模锻过程进行了数值模拟,正交模拟试验的结果表明,模具飞边槽桥部宽度b对模锻成形质量影响最大,依次为坯料大头过渡圆角半径r1、模具飞边槽桥部高度h和坯料小头过渡圆角半径r2;生产中采用优化的叶片尺寸及模具结构参数,使材料利用率提高了6.43%,锻打次数减少了2次,终锻件的尺寸精度有了大幅度提高。

High temperature deformation behaviors of turbine blade material and forging parameter optimization

For the turbine rotor blades forging process,the method of the combination of physical experiment and numerical simulation is adopted to study high-temperature deformation behavior of the materials and optimize the forging process parameters.The high-temperature thermal simulation experiments of 1Cr12Ni2W1Mo1V alloy show that the high temperature compression flow stress of 1Cr12Ni2W1Mo1V alloy accords with hyperbolic sine function.The high temperature constitutive equation is established and the material behavior database of stainless steel in high temperature is enriched;The constitutive equation is used to simulate the turbine blades forging process,and the orthogonal simulation test results show that the order of effect on forming quality is the bridge width of the flash slot on the die-b,the big head transition radius of blank bulk-r1,the bridge height of the flash slot on the die-h and the small head transition radius of blank bulk-r2.The blank and die optimized are used in production,the results are as follow: material utilization rate is increased 6.43 percent,the forging number is decreased by two times,the dimensional accuracy of blades production is substantially increased.