1. Research Institute of Tubular Goods, CNPC, Xi’an 710065, Shanxi, China;2. School of Material Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, Shanxi, China
Abstract：Impact Charpy toughness and local brittleness of HAZ of X80 linepipes made in China were studied. It was shown that the impact toughness of HAZ is 50% of base metal.From 20 ℃ to -40 ℃, the fracture is changed from part brittleness to total brittleness.At 20 ℃,the radial region is a mixture of cavitation and cleavage fracture and at 20 ℃and 0 ℃ the microcracks could be observed in radial region and fibrous region, respectively.The microstructure of fracture surface of HAZ is of granular bainite,with characteristics of coarse crystal zone.The propagation of microcracks goes along grain boundaries, the size of M/A islands in granular bainite is increased, and the phenomenon of crack traversing through M/A island exists as the result of serious embrittlement of grain boundary in HAZ.
张小立;庄传晶;冯耀荣;赵文轸;霍春勇. X80级管线钢热影响区的局部脆化[J]. 钢铁, 2007, 42(3): 69-0.
ZHANG Xiaoli;ZHUANG Chuanjing;FENG Yaorong;ZHAO Wenzhen;HUO Chunyong. Local Brittleness of HeatAffected Zone of X80 Pipeline Steel. Iron and Steel, 2007, 42(3): 69-0.
2007, Vol. 42 
