Abstract：Abstract： 42CrMo anchor for wind power was suddenly ruptured during the installation process. The chemical composition of fracture sample was analyzed. The cause of fracture was studied by metallographic examination and scanning electron microscopy. The results showed that the fracture belonged to intergranular fracture. The over high content of Mn and the grain-boundary segregation of alloying elements such as P, Si and Cu were main reasons to cause intergranular fracture. In addition, too high quenching temperature in heating treatment caused coarse austenite grains. Meanwhile, the tempering temperature was close to the high-temperature temper brittle zone, which caused the segregation of impurity elements at the austenite grain boundary. The synergistic effect of these factors also caused the brittle fracture of materials.
2020, Vol. 38 
