氢对TC21合金高温变形行为的影响

Effects of Hydrogen on Hot Deformation Behavior of TC21 Alloys

采用连续升温金相法研究了氢对TC21合金相变温度的影响,通过热模拟压缩实验,研究了氢对TC21合金高温变形行为的影响。结果表明:置氢可以显著降低TC21合金的相变温度,置氢0.7%(质量分数,下同)的TC21合金相变温度为810℃,与未置氢合金相比,降幅达145℃;同时,置氢还可以有效降低TC21合金的流变应力,并且温度越低,应变速率越高,氢对流动应力的影响就越显著,变形温度为800℃,应变速率1s-1时,置氢0.28%后,稳态应力为202MPa,与未置氢合金相比降低了28%,相同应力水平条件下,置氢能够实现变形温度降低40℃,应变速率提高一个数量级。

The effects of hydrogen on the transformation temperature and hot deformation behavior of TC21 alloys were investigated through microscopic analysis and isothermal compression tests respectively.The results indicate that the transformation temperature of TC21 alloys decreases significantly after hydrogenating,so that the transformation temperature of TC21 alloys containing 0.7%（mass fraction）H is 810℃,which decreases by 145℃ compared with natural hydrogen.Meanwhile,the flow stress of TC21 alloys decreases effectively too after hydrogenating and the effects of hydrogen on flow stress become obvious with deformation temperature decreasing and strain rate increasing.The steady state stress of TC21 alloys containing 0.28%H reaches 202MPa,which decreases by 28% compared with natural hydrogen.Under the same stress level,deformation temperature decreases by 40℃ and strain rate increases one order of magnitude after hydrogenating.