Analysis and prevention of weld crater cracking in circumferential laser microwelding of automotive pressure sensors. (October 2021)

• Record Type: Journal Article
• Authors: Kenda, Miha; Klobčar, Damjan; Nagode, Aleš; Bračun, Drago
• Is Part Of: Engineering failure analysis. Volume 128(2021)
• Publication Date: 2021-10
• Subjects: Two-beam laser welding -- Continuous-wave -- Solidification cracking -- Weld termination regime -- Ramp-down -- Lap joint -- 17–4 PH steel -- Inconel 602; System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2021.105579
• Languages: English
• ISSNs: 1350-6307

Abstract

Highlights: 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. Abstract: 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.