Hot cracking investigation during laser welding of high-strength steels with multi-scale modelling approach

Hot cracking investigation during laser welding of high-strength steels with multi-scale modelling approach

Gao, H. (TU Delft (OLD) MSE-5)
Agarwal, G. (TU Delft (OLD) MSE-5)
Amirthalingam, M. (Indian Institute of Technology Madras)
Hermans, M.J.M. (TU Delft (OLD) MSE-5)

2017

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.

advanced high-strength steel
finite element model
Hot cracking
laser welding
phase field model

http://resolver.tudelft.nl/uuid:7269da70-7220-4013-9ccc-c7868d0fa248

https://doi.org/10.1080/13621718.2017.1384884

1362-1718

Science and Technology of Welding and Joining, 23 (2018) (4), 287-294

Institutional Repository

journal article

© 2017 H. Gao, G. Agarwal, M. Amirthalingam, M.J.M. Hermans