TY - JOUR
T1 - Evaluation of solidification cracking susceptibility during laser welding in advanced high strength automotive steels
AU - Agarwal, G.
AU - Kumar, A.
AU - Richardson, I. M.
AU - Hermans, M. J.M.
PY - 2019
Y1 - 2019
N2 - Solidification cracking susceptibility during laser welding was studied experimentally and numerically in advanced high strength steel sheets, namely transformation-induced plasticity (TRIP) and dual phase (DP) steel. Using the same heat input, laser bead-on-plate welding was carried out on single sided clamped specimens at various starting distances from the free edge. It was observed that TRIP steel with high phosphorus is susceptible to cracking while in DP steel with low phosphorus, solidification cracking was not observed. The metallurgical factors affecting the solidification cracking were studied and it was found that solidification morphology, phosphorus segregation at the prior austenite grain boundaries, inclusions, interface growth rate and interdendritic liquid feeding have a prominent effect on the strength of the mushy zone. These results are discussed pertaining to the cracking mechanism. For the same welding parameters, a difference in the weld pool shape was observed in both the steels, which is attributed to the high temperature thermophysical properties. Weld pool shape affects the strain distribution in the mushy region and thus the cracking behaviour. The cracking phenomenon is further described using hot ductility curves.
AB - Solidification cracking susceptibility during laser welding was studied experimentally and numerically in advanced high strength steel sheets, namely transformation-induced plasticity (TRIP) and dual phase (DP) steel. Using the same heat input, laser bead-on-plate welding was carried out on single sided clamped specimens at various starting distances from the free edge. It was observed that TRIP steel with high phosphorus is susceptible to cracking while in DP steel with low phosphorus, solidification cracking was not observed. The metallurgical factors affecting the solidification cracking were studied and it was found that solidification morphology, phosphorus segregation at the prior austenite grain boundaries, inclusions, interface growth rate and interdendritic liquid feeding have a prominent effect on the strength of the mushy zone. These results are discussed pertaining to the cracking mechanism. For the same welding parameters, a difference in the weld pool shape was observed in both the steels, which is attributed to the high temperature thermophysical properties. Weld pool shape affects the strain distribution in the mushy region and thus the cracking behaviour. The cracking phenomenon is further described using hot ductility curves.
KW - Advanced high strength steels
KW - Automotive
KW - Laser welding
KW - Solidification cracking
KW - Weld pool shape
UR - http://www.scopus.com/inward/record.url?scp=85070560422&partnerID=8YFLogxK
U2 - 10.1016/j.matdes.2019.108104
DO - 10.1016/j.matdes.2019.108104
M3 - Article
AN - SCOPUS:85070560422
SN - 0264-1275
VL - 183
JO - Materials and Design
JF - Materials and Design
M1 - 108104
ER -