Shaoqing GUO
,
Xiaohong LI
,
Wenli XU
,
Xuesong LIU
,
Xin WAN
,
Xitang TIAN
材料科学技术（英）
The mechanism and effectiveness of welding distortion mitigation by static thermal tensioning were investigated by both finite element analysis and experiments. It shows that preset thermal tensioning can reduce longitudinal plastic compression remained in the weld and its adjacent zone significantly, so decrease the longitudinal residual stress and the susceptibility to welding distortion.
关键词:
Liang ZHANG
,
Xuesong LIU
,
Linsen WANG
,
Ping WANG
,
Hongyuan FANG
金属学报(英文版)
To investigate fatigue crack initiation characteristics of Al-Zn-Mg alloy welded joint, notched specimens were used in fatigue test for the base metal, welding bead and heat affected zone (HAZ). The fatigue fracture surface near the fatigue crack initiation site was observed by scanning electron microscope (SEM). The results show that the differences of fatigue crack initiation life among base metal, welding bead and HAZ are not obvious. Inhomogeneity in microstructure and mechanical performance of HAZ influences the fatigue crack initiation life. The ratio of fatigue crack initiation life (Ni) to fatigue failure life (N f)Al-Zn-Mg alloy|Welded joint|Fatigue crack initiation|Life prediction for the base metal, welding bead and HAZ of A7N01 aluminium alloy welded joint are 26.32%, 40.21% and 60.67%, respectively. Fatigue crack initiation life can be predicted using a uniform model. Observation of fatigue fracture surfaces shows that for the welding bead a fatigue crack initiates from the smooth surface due to the welding process, the blowhole in HAZ causes fatigue crack and the crushed second phase particles play an important role in fatigue crack initiation for the base metal.
关键词:
Al-Zn-Mg alloy
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