Understanding the factors controlling the interfacial failure strength of advanced high-strength steel resistance spot welds: hardness vs. fracture toughness

作者：Pouranvari Majid^*

来源：Science and Technology of Welding and Joining, 2018, 23(6): 520-526.

DOI：10.1080/13621718.2017.1421303

• Advanced high-strength steel
• resistance spot welding
• hardness
• toughness
• failure

The failure of advanced high-strength steels' spot welds is a critical issue for automotive crash-worthiness. This paper deals with understanding the underlying factors of the tensile-shear strength of automotive steels' resistance spot welds during interfacial failure. It was found that the ratio of the fracture toughness to the hardness of the fusion zone is the critical factor governing the interfacial failure mechanism: ductile shear failure (controlled by the fusion zone hardness) vs. cleavage crack propagation (controlled by the fracture toughness). This clarification could pave the way for more accurate modelling of interfacial failure of advanced steel resistance spot welds and shed light on the design of proper post-weld heat treatment for improving the weld mechanical performance.

• 出版日期2018