【摘要】 以超临界汽轮机叶片用1Cr11MoNiW1VNbN不锈钢为研究对象,测试叶片模拟工作温度下拉压疲劳极限的变化规律,用扫描电镜观察试样宏观及微观断口。结果表明,1Cr11MoNiW1VNbN不锈钢试样的疲劳极限随试验温度的变化有明显变化。当试验温度为538、566、593℃时,试验钢的拉压疲劳极限的最大变化量为81 MPa。其疲劳试样宏观断口包括裂纹萌生、裂纹扩展及最终断裂3个阶段,存在明显的裂纹前沿;微观断口具有典型的准解理断口特征。更多还原

【Abstract】 Fatigue property of 1Cr11NiMoW1VNbN stainless steel vane used in supercritical steam turbine was investigated.The variation law of tension-press fatigue limit of the specimens under different temperatures was discussed.The morphology of the fracture surfaces was examined by scanning electron microscope.The results show that the fatigue limit of the 1Cr11NiMoW1VNbN steel changes evidently with the temperature changing.Maximal varying value of tension-press fatigue limit of the test steel under the temperature of 538,566 and 593 ℃ is 81 MPa.Macro-fracture surface of the fatigue specimens includes the crack initiation,the crack extension and the ultimate fracture,and presents obviously crack front edge.Micro-fracture surface presents typical quasi-cleavage fracture characterization.更多还原