Effect of volume fraction of bainite on microstructure and mechanical properties of X80 pipeline steel with excellent deformability

► The dual-phase X80 can be obtained by accelerating cooling in the intercritical zone. ► The strength and the Y/T increase of dual-phase X80 with the increase of VB. ► The n and ductility of dual-phase X80 decrease monotonously with the increase of VB. ► The impact toughness of dual-phase X80 decreases little with the increase of VB. ► The dual-phase X80 has excellent deformability as the VB is about 50%.