压力容器用钢低周疲劳表面裂纹扩展速率试验研究

压力容器的表面裂纹常常会导致低周疲劳破坏.因此,研究压力容器用钢的低周疲劳表面裂纹扩展规律,具有重要意义.本文在带有上下对称圆弧板状试样的上圆弧几何中心,加工预制了半椭圆表面裂纹,以模拟压力容器具有表面裂纹时的特点.同时,在上圆弧一侧设计加工了特定形状和尺寸的刀口,装卡COD位移规,用来控制表面裂纹前缘的应变.以10C...

Test Study on Low Cycle Fatigue Surface Crack Propagation Rate for Pressure Vessel Steel

Since surface crack propagation in pressure vessel often results in low cycle fatigue destruction,it is of significance to figure out low cycle fatigue surface crack propagation law.On the specimen with symmetrical double arcs,a semi-ellipse surface crack in the geometric center of the up-arc was machined and fatigue-prepared to simulate the character of pressure vessel with a surface crack.Simultaneously,in the arc side a knife-edge with a special shape and dimension for installing a COD displacement gage was designed to control the strain of surface crack front.With 10CrNiMo steel as an example,under cantilever bending loading mode,with a total six-grade strain range from small to big as the controlled parameters,the low cycle fatigue surface crack growth characteristics of the test material was investigated,which may provide a reference for assessing the remaining useful life of pressure vessels with surface cracks in it.