褚武扬
,
肖纪美
,
A.W.THOMPSON
金属学报
对解理开裂,对氢致解理,氢能促进位错的增殖和运动,从而σ_0(H)<σ_0,k>1,即σ_F(H)<σ_F,K_(IH)
关键词:
Ti_3Al
,
intermetallic compound
,
hydrogen induced crack
王荣
机械工程材料
doi:10.11973/jxgccl201512025
42CrMoA 钢制内齿圈在加工结束后产生了裂纹，采用光学显微镜、扫描电子显微镜和显微硬度计等对裂纹产生的原因进行了分析。结果表明：裂纹的形成是因感应淬火工艺不当造成的，同时钢中还产生了较大的热处理残余内应力，钢中的氢和环境氢会向应力集中严重的淬火裂纹尖端富集，形成局部氢浓度升高，使初始淬火裂纹在残余应力作用下又以氢致延迟性裂纹继续扩展；通过采用正确的热处理工艺，在淬火后及时进行回火以改善淬硬层组织可预防开裂。
关键词:
淬火裂纹
,
42CrMoA 钢
,
内齿圈
,
氢致延迟开裂
CHU Wuyang XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
ChinaTHOMPSON AW Carnegie Mellon University
,
U.S.A
金属学报(英文版)
Both hydrogen induced cracking and overload crack initiated at same characteristic distance, r~*,within the plastic zone along the slip line when the plastic zone developed to a critical ex- tent.For the overload crack. K_(IC)=αr~*~(1/2)[σ_F~((n+1)/2n)/σ_(ys)~((1-n)/2n)],σ_F=σ_0+g[2μbσ_(th)/π~2L(1-v)]~(1/2) For the hydrogen induced cracking: K_(IH)=αr~*~(1/2)[σ_F(H)~((n+1)/2n)/σ_(ys)(H)~((1-n)/2n)], σ_F(H)={σ_0(H)+g[2μbσ_(th)(H)/π~2L(1-v)]~(1/2)}/k Hydrogen pomoting the dislocation multiplication and motion would result in σ_0(H)<σ_0, k>1,Therefore,hydrogen promoting the cleavage fracture in titanum aluminide can be due to that hydrogen facilitates the local plastic deformation,which results in σ_F(H)<σ_F and then K_(IH)
关键词:
Ti_3Al
,
null
,
null
