Hot cracking investigation during laser welding of high-strength steels with multi-scale modelling approach. (19th May 2018)

• Record Type: Journal Article
• Authors: Gao, H.; Agarwal, G.; Amirthalingam, M.; Hermans, M. J. M.
• Is Part Of: Science and technology of welding & joining. Volume 23:Number 4(2018)
• Page Start: 287
• Page End: 294
• Publication Date: 2018-05-19
• Subjects: Hot cracking -- laser welding -- finite element model -- phase field model -- advanced high-strength steel; Welding -- Periodicals; Joints (Engineering) -- Periodicals; Surfaces (Technology) -- Periodicals; 671.52
• DOI: 10.1080/13621718.2017.1384884
• Languages: English
• ISSNs: 1743-2936

Abstract

ABSTRACT: Hot cracking during laser welding of advanced high-strength steels is reported to be a serious problem by automotive manufacturers. In this work, hot cracking susceptibilities of transformation-induced plasticity (TRIP) and dual-phase (DP) steels are studied based on a multi-scale modelling approach. Transient temperatures measured from welding experiments are used to validate a finite element (FE) model. The temperature, thermal gradient and cooling rate in the weld fusion zone are extracted from the FE model and pre-defined as boundary conditions to a phase field model. The welding-induced microstructural evolution is simulated considering thermodynamic and mobility data. Results show that, compared to the DP steel, the TRIP steel has a broader solidification range, a greater pressure drop at the inter-dendritic regions, and an increased phosphorus segregation at the grain boundaries; all these make this steel more susceptible for hot cracking.