Air cooled bainitic steels for strong, seamless pipes Part 2 – properties and microstructure of rolled material

In the first part of the present study, two steels were designed with the aim of achieving properties consistent with the specifications for the manufacture of seamless pipes. The alloys were intended to develop into mixtures of bainitic ferrite and carbon enriched retained austenite during cooling to ambient temperature from the pipe forming operations, thus avoiding the need for subsequent heat treatment. Part 2 of the study deals with the characterisation and understanding of the mechanical properties of the two alloys. Good combinations of strength and toughness have been achieved.