| Abstract Scope |
One of the key properties of HSLA steels is their ability to absorb energy during crack propagation, which helps prevent product failure. Given the general principles for improving toughness, the importance of achieving a homogeneous and finely dispersed final microstructure is clear. Even isolated large grains in the final structure - typically inherited from the original austenite - can significantly reduce the steel's resistance to fracture. These coarse grains often originate from abnormal austenite grain growth during slab reheating and are further exacerbated by non-uniform austenite structures after roughing rolling, caused by differences in recrystallization kinetics between grains of different sizes.
Considering this, comprehensive research was conducted to study the effect of different Nb–Ti microalloying concepts, including Nb-only, Ti-only, and combined Nb–Ti additions, on abnormal austenite grain growth during reheating and on structure evolution during roughing rolling. |