孙昊1, 2，谭啸1, 2，王海燕1, 2，任慧平1

（1.内蒙古科技大学省部共建国家重点实验室，内蒙古，包头，014010

2.内蒙古科技大学材料与冶金学院，内蒙古，包头，014010）

关键词： X80管线钢；终冷温度；显微组织；落锤撕裂性能

中图分类号：TF046.6 文献标识码：A

摘要：控轧控冷工艺对X80 管线钢的力学性能有重要影响。本文通过断口形貌和显微组织观察，对比分析不同终冷温度条件下显微组织与X80 管线钢落锤撕裂性能的关系。结果表明：随着终冷温度的降低，珠光体含量减少，多边形铁素体含量逐渐增加，有利于管线钢的落锤撕裂性能的提高。当终冷温度为600℃时，多边形铁素体作为主要基体组织存在，晶粒细小均匀，出现多边形铁素体晶粒聚集区域，落锤撕裂面积均匀，落锤撕裂性能最好。

Relationship between Microstructure and DWTT Property of X80 Pipeline Steel of different Final Cooling Temperature

Hao Sun1, 2,Xiao Tan1, 2, Haiyan Wang1, 2, Huiping Ren1

（1.Key Laboratory of Bayan Obo Multi-metal Resources, Inner Mongolia University of Science and Technology,Baotou, Inner Mongolia, 014010, China；2.School of Material and Metallurgy, Inner Mongolia University of Science and Technology, Baotou, Inner Mongolia, 014010, China）

Key words：X80 pipeline steel；Final cooling temperature ；Microstructure； DWTT property

Abstract：Controlled rolling process of controlled cooling has important influence on the mechanical properties of X80 pipeline steel. The relationship between microstructure and DWTT property of X80 pipeline steel under different final cooling temperature was analyzed by means of fracture morphology and microstructure observation. The results show that with the decrease of the final cooling temperature，the pearlite content reduced and the polygonal ferrite content increased gradually，which is beneficial to the improvement of the pipeline steel DWTT property. DWTT property is the best under final cooling temperature of 600 ℃ ，as the polygonal ferrite exists mainly as matrix organization with fine and uniform crystal grains，polygonal ferrite crystal grains gathered area appears ,and DWTT area is even..