含亚稳奥氏体铬锰氮不锈钢的拉伸变形特性研究

Study on tensile deformation characteristic of CrMnN stainless steel with metastable austenite

研究了一种含亚稳奥氏体铬锰氮不锈钢在拉伸变形过程中的力学特性与组织变化,并对其加工硬化机制进行了讨论。结果表明,0Cr13Mn9N钢的-曲线在塑性变形区可分为3个阶段,初期和后期与一般不锈钢的基本相似,中期则具有d2d2>0这种与通常情况不同的走向;应变诱发马氏体转变对外加变形能量的吸收或弛豫,使其在变形的不同阶段具有差异显著的加工硬化特性;该钢的加工硬化机制包括:初始马氏体在变形过程中的加工硬化,变形过程中产生的应变诱发马氏体相变和诱发马氏体本身在后续变形过程中的加工硬化,未转变奥氏体的加工硬化及其内部N(C)原子与运动位错相互作用产生的动态应变时效所引起的加工硬化。

The mechanical characteristics and structural changes ofa CrMnN stainless steel with metastable austenite during tensile deformation are investigated and the work-hardening mechanism is discussed. The results show that the part of plastic deformation of s-e curve for 0Cr13Mn9N steel can be divided into three stages. At the initial and later stages, it is notsimilar to that of the common stainless steels, but at the middle stage, it presents the trend （d^2s/de^2〉0） that is different from the ordinariness. B^ause of absorb and relax of additional energy by the strain-induced martensitic transformation during deformation, the steel has much more different work-hardaning properties at the different stages. The work-hardening mechanism of the steel consists of the strain- induced martensitic transformation, the work-hardaning of the induced and quenched martensite, the work-hardening of austvnite and the dynamic strain aging due to the interaction between motion dislocation and the N （C） atoms.