Modified 9 Cr-1Mo steel is a material of prime significance in power plants used for components of steam generation units. The phenomenon of ratcheting involves aggregation of plastic strain in each cycle during asymmetric cyclic stressing. In the present study, the role of prior ratcheting has been studied on tensile behavior of this steel at ambient temperature. Cyclic tests were performed under uniaxial stress under the three parameters namely mean stress (σ_m), stress amplitude (σ_a) and stress rate \((\dot{\sigma })\) for 200 cycles. Tensile behavior of the pre-ratcheted samples was evaluated at ambient temperature at a strain rate of 10⁻⁴ s⁻¹. It was found that pre-ratcheting enhanced the yield strength (S_YS) and tensile strength (S_UTS) but reduced the ductility. The results are discussed in terms of cyclic hardening resulting from the pre-ratcheting under different variables, and the internal microstructural changes are revealed by transmission electron microscopy.

改性9 Cr-1Mo钢是用于发电厂中用于蒸汽发电设备组件的重要材料。棘轮现象涉及在非对称循环应力作用下的每个循环中塑性应变的聚集。在本研究中，已经研究了先行棘轮对这种钢在环境温度下的拉伸性能的作用。循环试验的三个参数，即平均应力（下单轴应力下进行σ_米），应力振幅（σ_一个）和应力速率\（（\点{\西格玛}）\）为200次循环。在环境温度下以10 ^-4  s ^-1的应变速率评估预棘轮式样品的拉伸行为。发现预棘轮提高了屈服强度（S _YS）和拉伸强度（S _UTS），但降低了延展性。讨论了在不同变量下预棘轮引起的循环硬化结果，并通过透射电子显微镜揭示了内部微观结构的变化。