Two high-strength low-alloyed steels alloyed with various Nb contents were prepared using continuous casting (CC) technology. In the round Steel 30Nb CC billet, it was segregation of C and in central equiaxed zone that promoted precipitation primary NbC carbides at grain boundaries. After processing into seamless tubes, micron-sized located middle bands, surrounded by many nano-sized formed dur...

The aim of the paper was to investigate helical rolling parameters (a number passes) for microstructural modification and low-temperature impact toughness improvement 09Mn2Si High Strength Low-Alloyed (HSLA) steel. In order achieve this purpose, work spent crack initiation propagation analyzed compared with patterns fracture surfaces. microstructure values were presented in temperature range fr...