Fracture toughness of the materials in welded joint of X80 pipeline steel

• DOI: 10.1016/j.engfracmech.2015.07.061
• Publication Date: 2015-08-07T00:42:53Z
• Authors: Yonghe Yang; Lei Shi; Zhen Xu; Hongsheng Lu; Xu Chen; Xin Wang
• Keywords: 0205 materials engineering; 02 engineering and technology

Abstract The microstructures, mechanical properties and fracture toughness of the materials in different locations of the welded joint of the X80 pipeline steel were studied at room temperature. Elastic–plastic fracture toughness testing of crack tip opening displacement (CTOD) and J-integral of the welding materials and base material were conducted. A new non-contact double-clip gauge measuring system was developed and used in the fracture toughness tests. It was observed the fusion zone (FZ) was the fracture risk zone of the X80 steel weldment; and the occurrence of hard-brittle martensite–austenite (M–A) constituents was a significant because of welding hardening and embrittlement.