| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Advances in Metallic Coated Advanced Steels
|
| Presentation Title |
Insight into the Mechanism of Liquid Metal Embrittlement in Resistance Spot Welding of Zn-coated Dual Phase Steel: The Role of Boron and Silicon |
| Author(s) |
Elahe Akbari, Philipp Kürnsteiner, Peter Oberhumer, Günter Hesser, Heiko Groiss, Martin Arndt, Martin Gruber, Robert Sierlinger |
| On-Site Speaker (Planned) |
Elahe Akbari |
| Abstract Scope |
Despite numerous studies on liquid metal embrittlement (LME) during welding of Zn-coated 3rd generation advanced high strength steels (AHSS), a conclusive mechanism demonstrating how different alloying elements such as boron and silicon influence LME behavior, is still missing.
In the present study, hot tensile tests were conducted to study LME susceptibility in high ductility dual phase (DP-HD) steel. Results indicated that the presence of boron, as well as decreasing silicon-content from 1.5% to 0.9%, mitigate LME sensitivity at elevated temperatures. Electron backscatter diffraction in conjunction with transmission electron microscopy verified the intergranular penetration of Zn along prior austenite grain boundaries, where Zn as a ferrite stabilizer promotes the formation of α-Fe(Zn). Those Zn- wetted grain boundaries present a promising path for LME crack propagation. LME cracks in resistance spot welded DP-HD steels were investigated and the grain boundaries that are prone to LME crack propagation were analyzed in detail. |