夹杂物几何特征对拉伸过程中X80管线钢中裂纹萌生及扩展的影响

Effect of Geometrical Characteristics of Inclusions on Initiation and Propagation of Cracks in X80 Pipeline Steel during Tensile Test

采用扫描电镜原位观察的方法,研究了在拉伸过程中X80管线钢中夹杂物的尺寸、形态对裂纹萌生与扩展的影响。结果表明:在拉伸过程中,夹杂物尺寸越大,夹杂物内萌生的裂纹数量越多,第1条裂纹萌生时的应力越小;夹杂物的形态和尺寸决定第1条裂纹的萌生位置;夹杂物的尺寸、形态对X80管线钢的拉伸强度无显著影响。

The effect of size and shape of inclusions in X80 pipeline steel on crack initiation and propagation during tensile test was studied by scanning electron microscopy in--situ observation. The results show that the larger the size of an inclusion, the more the number of cracks initiated in the inclusion, and the lower the stress of the first crack initiation. The shape and size of inclusions determined the location of the first crack initiation, and the size and shape of inclusions had not remarkable effect on the tensile strength of X80 pipeline steel.