Changli WANG
,
Zhimin WAN
,
Min ZHAO
,
Jitai NIU
材料科学技术（英文）
The fatigue properties of 2024T3 aluminum alloy welded joint treated by different peening methods were examined. The different effects on fatigue performance of high strength aluminum welded joints were compared with each other by carry out a series tests using two different peening treatment samples. Results show that by applying synchronized hammer peening to the weak part of joint when weld was going on, trailing peening, may refine the grains near weld line, hardening the surface of weld toe and amend the distribution of residual stress. Because of these results the position of fracture of joint was moved from weld toe to weld line. Compared to the joints treated by peening after welding, the fatigue strength of weld joint treated by trailing peening was enhanced by more than 102%.
关键词:
Fatigue strength
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Satoshi HANAK
,
Yahong SUI
,
Masato YAMASHITA
,
Hitoshi UCHIDA
,
Hironobu TSUJII
材料科学技术（英文）
It is reported that laser-processing is effective to repair the heat checks, which are fine shallow cracks on a surface of die-casting dies. In this study, the rotating bending fatigue tests have been carried out to evaluate the fatigue characteristics of laser-processed hot working tool steel. Because test results are scattered, S-N curves are decided based on the evaluation of fatigue strength distribution. As a result, the fatigue strength of the laser-processed specimens decreases remarkably in comparison with that of base metal. However, it can be recovered to almost initial value by heat treatment at secondary hardening temperature. This procedure is also effective to decrease the scatter of fatigue strength. The laser-processing can be carried out at low cost and this method is effective for the extension of the work life of dies.
关键词:
Hot working tool steel
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