关键词: TBM刀盘, 单轴抗压强度, 动力稳定性, 数值仿真, 推进速度, 奥氏体不锈钢, 变形, 低温, 马氏体转变

Abstract: The low cycle fatigue test of austenitic stainless steel 1Cr18Ni9Ti has been conducted at room and low temperature in this paper. Cyclic hardening mechanism and microstructure changes during strain cycling have been studied. Cyclic hardening was observed at room and low temperature. Ε and α′ marten site can be formed by strain cycling in the austenitic stainless steel 1Cr18Ni9Ti at room and low temperature. The content of ε marten site is less than 1.5% and the α′marten site is plate-like and blocky. The mechanism of cyclic hardening of 1Cr18Ni9Ti steel is the following. Cyclic hardening results mainly from the formation of marten site during strain cycling. When the balance between the hardening resulting from newly formed marten site and the softening of marten site formed early is established, the cyclic hardening saturation is reached.

Key words: driving speed, dynamic stability, numerical simulation, TBM cutterhead, uniaxial compressive strength, 奥氏体不锈钢, 变形, 低温, 马氏体转变