A simulation analysis of crack growth for X80 and X100 pipeline steels

To identify the crack arrest property of high-grade pipeline steel, a crack growth analysis model is established with the finite element software ABAQUS. The model is used to analyze the initial cracks existing in the inner walls of pipeline and simulate the whole process of crack growing from the inner wall to the outer wall and then axially along the pipe. The crack growths of X80 and X100 pipeline steels are compared. The results have proved that the crack of X100 pipeline steel extends rapidly under the influence of gas pressure, although the drop of pipeline pressure caused by leakage reduces the crack growth speed; consequently, external effect is needed to thoroughly arrest the crack. When there is no crack, X100 pipeline steel can effectively resist the generation of crack; when the crack has begun to grow, X80 pipeline steel can effectively resist the crack growth. It is thus clear that X80 pipeline steel has a stronger ability to resist crack growth than X100 pipeline steel. X100 pipeline steel and X80 pipeline steel are preferably combined in engineering application.