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  • Analysis and prevention of ...
    Kenda, Miha; Klobčar, Damjan; Nagode, Aleš; Bračun, Drago

    Engineering failure analysis, October 2021, 2021-10-00, Letnik: 128
    Journal Article

    •Autogenous laser welding produces concave end-crater in 17–4 PH that is prone to solidification cracking.•Solidification cracking at weld end-crater causes weld leakage.•The use of novel zigzag laser power ramp-down profile produces significantly shorter, discontinuous, and leakage free cracks. An analysis presents a weld leakage problems of automotive pressure sensor, caused by weld crater cracking. A two-beam laser welding (TBLW) was used to weld a circumferential weld, which undesirably increases the probability of weld leakage by creating two weld end craters on a single weld. Microstructural analysis showed that microsegregation of alloying elements combined with imposed strains causes solidification cracking at the weld end crater. A novel “zigzag” laser power ramp-down was used and the results showed a limited crack propagation by producing significantly shorter discontinuous cracks. In such weld crater endings the leakage is no longer an issue.