Study on the Fracture Toughness of X80 Pipeline Steel

X80 pipeline steel is employed to study the thickness effect on fracture toughness.Three point bending method is taken to perform the experiment for X80 steel with different thickness.GB 2038—91 standard is employed to conduct the fracture toughness test.The results show that there is a complex relationship between JC and the thickness,as well as the correlation between fracture toughness resistant curve and the thickness is complex as well.The corresponding achievement is beneficial to fracture toughness assessment and safety evaluation for high strength pipeline.