About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Advancements in Steel Structural Refinement
|
| Presentation Title |
Favorable Mechanical Performance by Controlled Characteristics of Local Brittle Zone in Nb Bearing HSLA Steel for Ultra-High Heat Input Welding |
| Author(s) |
Seonghoon Yoo, Namhyun Kang |
| On-Site Speaker (Planned) |
Seonghoon Yoo |
| Abstract Scope |
The formation of local brittle zone renders several beneficial strengthening mechanisms meaningless in heavy plates. The present study reports on the microalloying to achieve favorable mechanical performance. Nb microalloying was applied to control the characteristics of the local brittle zone of as-rolled plates and coarse-grained heat-affected zone (CGHAZ) in low carbon steel used for ultra-high heat input welding. The controlled characteristics of MA constituents such as size, volume fraction, carbon concentration and micro-hardness, the UTS of as-rolled plates was significantly improved by 20% without sacrificing the ductility and impact toughness. More interestingly, the increased Nb content suppressed the formation of grain boundary ferrite in CGHAZ. This controlled microstructure changed the fracture behavior and facilitated the remarkable improvement in impact toughness for CGHAZ. Therefore, the microstructure managed by Nb microalloying resulted in notable mechanical properties and weldability. |