电子束滴熔工艺对DZ125返回料主元素挥发影响OA

Electron beam(EB)melting has the characteristics of high temperature,extreme overheating,and high vacuum,which have unique advantages in removing refractory inclusions in the revert of hafnium containing superalloys.But during purification,it also brings about the problems of key active element burnings.In this project,the electron beam melting process experiments had been carried out by using of a 300 kW EB drip melting equipment,and the influences of different electron beam process parameters such as melting power,melting rate,and vacuum degree on the volatilization of active elements in the revert alloy were investigated.It was observed through the experiments that the condensation phenomena of evaporated main elements existed during the melting processes,and besides the matrix element Ni,Cr was the main burned element during the EB drip melting processes.Through quantitatively characterizings of the actual ingot compositions before and after the EB drip melting,the affecting laws of the process parameters on the burning loss conditions of main elements were established.The results show that the process parameters of having the greatest impact on the burning loss of main elements are melting power and melting rate.As the melting rate is decreased to 5.0 mm/min and the melting power is increased to 55 kW,the burning loss rate of Cr element is significantly increased from 0.91％to 40.41％,and at this time,the temperature of the molten pool is reached to 2 410 ℃.