Improving the fatigue limit and rendering a defect harmless by laser peening for a high strength steel welded joint
Improving the fatigue limit and rendering a defect harmless by laser peening for a high strength steel welded joint
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DOI：
10.1016/j.optlastec.2020.106605
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发表时间：
2021-02
影响因子：
5
通讯作者：
R. Fueki;Koji Takahashi
中科院分区：
文献类型：
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作者：
R. Fueki;Koji Takahashi
研究了激光喷丸对HT 780钢（JIS-SHY 685）焊接接头疲劳极限的提高和可接受缺陷尺寸的影响。疲劳试验进行后，LP条件的优化。无缺陷焊接试件的疲劳极限提高了45%。在焊趾处含有0.2 mm深半圆形缺陷的试样达到与无缺陷的LP处理试样几乎相同的疲劳极限水平。因此，LP可使深度小于0.2 mm的半圆形缺损无害。结果表明，LP处理能显著提高高速钢焊接接头的疲劳强度和可靠性。导致疲劳极限提高的主要因素是LP引入的压缩残余应力。
The effects of laser peening (LP) on fatigue limit improvement and acceptable defect size of a high strength steel HT780 (JIS-SHY685) welded joint were investigated. Fatigue tests were performed, following the optimization of the LP conditions. The fatigue limit of the welded specimen without the defect increased by 45% via LP. The specimen containing 0.2 mm deep semicircular defect at the weld toe reached almost the same level of fatigue limit as that of the defect-free, LP-treated specimen. Therefore, a semicircular defect of less than 0.2 mm deep could be rendered harmless by LP. From the results, the fatigue strength and the reliability of HSS-welded joints can be significantly improved by LP. The dominant factor that contributed to fatigue limit improvement was the introduction of compressive residual stress by LP.