Magnesium stress corrosion cracking

摘要：

The significant positive green environment influence of magnesium alloy usage in transport could be compromised by catastrophic fast fracture caused by stress corrosion cracking (SCC).Transgranular stress corrosion cracking (TGSCC) of AZ91 was evaluated using the linearly increasing stress test (LIST) and the constant extension rate test (CERT).The TGSCC threshold stress was 55.75 MPa in distilled water and in 5 g/L NaCl.The TGSCC velocity was 7×10.10.5×10.9 m/s.A delayed hydride-cracking (DHC) model for TGSCC was implemented using a finite element script in MATLAB and the model predictions were compared with experiment.A key outcome is that,during steady state TGSCC propagation,a high dynamic hydrogen concentration is expected to build up behind the crack tip.A number of recommendations are given for preventing SCC of Mg alloys in service.One of the most important recommendations might be that the total stress in service (i.e.the stress from the service loading + the fabrication stress + the residual stress) should be below a threshold level,which,in the absence of other data,could be (conservatively) estimated to be about 50％ of the tensile yield strength.

关键词： stress corrosion cracking linearly increasing stress test LIST CERT hydrogen

作者: N.Winzer A.Atrens W.Dietzel G.Song K.U.Kainer

作者单位: Materials Engineering,The University of Queensland,Brisbane,Australia Materials Engineering,The University of Queensland,Brisbane,Australia;Swiss Federal Laboratories for GKSS-Forschungszentrum Geesthacht GmbH,Germany

会议类型: 国际会议

会议名称: 2007年国际有色金属大会(International Conference of Nonfereous Materials 2007)(ICNFM)

会议地点: 长沙

会议语种:英文

在线出版日期: 2007-11-28（万方平台首次上网日期，不代表论文的发表时间）