氢对Ti-4Al-2V钛合金疲劳寿命的影响  

Effects of Hydrogen on Fatigue Life of Ti-4Al-2V Titanium Alloy

作　　者：何晓[1] 岳俊[2] 沈保罗[1] 曹建玲[1] 邱绍宇[3] 邹红[3] 

机构地区：[1]四川大学金材系,成都610061 [2]成都飞机工业(集团)公司,成都610092 [3]中国核动力研究设计院,成都610041

出　　处：《核动力工程》2003年第4期297-301,共5页Nuclear Power Engineering

摘　　要：采用变截面薄板试样．研究了4种氢含量对Ti-4A1-2V钛合金疲劳寿命的影响。研究结果表明：当拉伸疲劳载荷Δσ大于550MPa时．充氢材料的疲劳寿命高于自然含氢量的材料；在高的Δσ下．含氢量在113-280μg·g^-1范围内变化时．对Ti-4A1-2V的寿命影响较小；Δσ降低后，氢含量越高，疲劳寿命越低，同时，Δσ的大小会影响疲劳裂纹的萌生位置。可以认为：材料中固溶氢和氢化物对驻留滑移带(PSB)的影响降低了充氢试样的疲劳裂纹萌生寿命，而高含氢量的Ti-4A1-2V材料在裂纹尖端，通过应力诱导析出氢化物．使裂纹扩展寿命降低。Four hydrogen contents had been employed to investigate the effects of hydrogen on fatigue life of Ti-4Al-2V titanium alloy by means of section-varied samples. Results revealed that the fatigue life of hydrogen-charged materials is higher than that of natural hydrogen material provided that fatigue load Δσ is over 550 MPa. At higher Δσ, content of hydrogen has small effects on fatigue life within 116~280μg/g, but the fatigue life declines with the rise of hydrogen content in case of lower Δσ. Besides, amount of hydrogen tends to influence the crack initiation site. Explanation for the results is that interstitial hydrogen atoms and hydrides affecting the Persistent Slip Bands(PSB) become the cause of the decreasing in fatigue initiation life, and stress-induced precipitation of hydrides near crack tips for high hydrogen content seems being the reason of decrease in fatigue propagation life.

关 键 词：钛合金 疲劳断裂 氢氢化物 

分 类 号：TG114[金属学及工艺—物理冶金]