Influence of Mn content on rolling performance of lean duplex stainless steel

Abstract

Cold rolling test as well as room temperature compression was carried out to investigated the influence of Mn content on the cold deformation properties of lean duplex stainless steel. The cold deformation mechanism was also discussed by observation of cold-rolled samples with cracks and analysis of the work hardening curve. The results demonstrated that the morphology and size of grains were both influenced by the Mn content. The quenched martensite content varied with Mn content, indicating that Mn plays critical role in both the difficulty of stress-induced martensite transformation of austenite grains in LDSS and the transformation process from austenite to martensite during solution treatment. LDSS with a lower Mn content exhibits lower austenite stability. After quenching, plenty of the austenite was transformed into martensite which performs much higher hardness than ferrite. With the increase in hardness difference between phases, the plasticity of the alloys decreased caused by each phase bore more uneven deformation.