奥氏体不锈钢低温力学性能研究综述

Review on Research of Mechanical Properties of Austenitic Stainless Steel at Low Temperature

综述了奥氏体不锈钢在低温下的力学性能演变规律并阐述了其变化机理。随着温度从室温降低至20 K,奥氏体不锈钢的屈服强度和抗拉强度显著增大,但是塑性和韧性却逐渐下降。然而,其拉伸和冲击断口形貌在20 K温度下断口依然呈现韧性断裂特征,没有发生韧脆转变现象,表明奥氏体不锈钢具有良好的低温塑性。低温下热诱发马氏体的形成是导致奥氏体不锈钢塑性降低的主要原因,添加C和N以及细化晶粒能明显提高奥氏体热稳定性。

The evolution rules of mechanical properties of austenitic stainless steel at low temperature was reviewed and the mechanism was expounded.With the temperature decreasing from room temperature to 20 K,the yield strength and ultimate tensile strength for the austenitic stainless steel significantly increased while the plastic and toughness showed a tendency of gradual decline.However,the tensile and impact fracture morphology was characterized by ductile rupture even at 20 K,without the occurrence of ductile-brittle transition,indicating that austenitic stainless steel had good low temperature plasticity.It was concluded that the thermal-induced martensite transformation was the main reason for the decrease of the plastic at low temperature.The addition of C and N,and grain refinement can improve the thermal stability of austenitic effectively.