Influences of Two-Stage Cooling Processes on Microstructure of Strain-Based Designed X70 Pipeline Steel

XUN Lei-Lei; BO Meng-Zhuo; ZHENG Lei

doi:10.13228/j.boyuan.issn0449-749x.20130713

Iron and Steel ›› 2014, Vol. 49 ›› Issue (9) : 81-86. DOI: 10.13228/j.boyuan.issn0449-749x.20130713

Influences of Two-Stage Cooling Processes on Microstructure of Strain-Based Designed X70 Pipeline Steel

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Steel with ferrite-bainite dual phase has been extensively researched for the strain-based designed pipeline applications owing to the high deformation resistance through successively yielding of the two phases. In order to explore the relationships of processes and dual-phase microstructure, the influences of two-stage controlled cooling processes on the microstructure transformation of deformed austenite in strain-based designed X70 pipeline steel are investigated through compression experiments conducted by Gleeble-3800. The results indicates that holding temperature for a short time after slow cooling stage could effectively promote ferrite precipitation, thereby refine ferrite grain. In addition, with the accelerated cooling start temperature lowering, the ferrite fraction increased. During the accelerated cooling stage, either increasing the cooling rate or lowering the cooling finish temperature could decrease the lath width and the sizes of carbides in the bainite structure and then improve the microhardness.

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XUN Lei-Lei, BO Meng-Zhuo, ZHENG Lei. Influences of Two-Stage Cooling Processes on Microstructure of Strain-Based Designed X70 Pipeline Steel[J]. Iron and Steel, 2014, 49(9): 81-86 https://doi.org/10.13228/j.boyuan.issn0449-749x.20130713

References

[1]李鹤林，李霄，吉玲康，陈宏达.油气管道基于应变的设计及抗大变形管线钢的开发与应用[J].焊管, 2007, 30(5):5-11 [2].Wang Y Y, Liu M, Rudland D, et al．Strain based design of high strength pipelines[C]// Proceedings of the 17th International Offshore and Polar Engineering Conference．Lisbon: 2007: 3186． [3].Ji L K，Chen H Y，Huo C Y，et al．Key issues in the specification of high strain line pipe used in strain-based designed districts of the 2nd west to east pipeline[C]// Proceedings of IPC 2008 7th International Pipeline Conference．Calgary: 2008: 1． [4]Ishikawa N, Parks D M, Socrate S, Kurihara M.Micromechanical modeling of ferrite-pearlite steels using Finite Element Unit Cell Models[J].ISIJ International, 2000, 40:1170-1179 [5].Ishikawa N, Okatsu M, Endo S, et al．Material design concept and production of high strength linepipe for strain-based design applications[C]// Strain-Based Design of Pipelines Seminar Forum: Beijing, 2007: 60． [6]Ishikawa N, Shikanai N, Kondo J.Development of ultra-high strength linepipes with dual-phase microstructure for high strain application[J].JFE Tech Rep, 2008, 12:15-19 [7]崔天成，郑磊，吴海凤.应变时效对不同成分高强度管线钢力学性能的影响[J].机械工程材料, 2010, 34(5):30-32 [8]沈显璞，雷廷权，刘剑壮.双相钢微观变形行为的动态研究[J].金属学报, 1987, 23(2):150-154 [9]郑晓飞，康永林，孟德亮，安守勇，夏佃秀.终轧温度对抗大变形管线钢组织性能的影响[J].北京科技大学学报, 2011, 33(5):557-562 [10].Zheng Lei, Bai Min-zhuo, Zhang Bei, Cui Tian-cheng, Xu Hai-shen．Research and Development of X70 Large Diameter UOE Linepipe With High Deformability for Strain-Based Design Pipeline[C]// Proceedings of the 2012 9th International Pipeline Conference．Calgary, Alberta, Canada: 2012． [11]李振华，张骁勇，高惠临，史维.终冷温度对大变形管线钢力学性能的影响[J].热加工工艺, 2011, 40(16):164-169 [12]孟德亮，康永林，郑晓飞，安守勇，夏佃秀.两阶段控制冷却工艺对含钼抗大变形管线钢组织与性能的影响[J].北京科技大学学报, 2011, 33(7):834-840 [13]焦多田，蔡庆伍，武会宾.轧后冷却制度对级抗大变形管线钢组织和屈强比的影响[J].金属学报, 2009, 45(9):1111-1116 [14].李鹤林，郭生武，冯耀荣，霍春勇，柴惠芬．高强度微合金管线钢显微组织与鉴别图谱[M]．北京：石油工业出版社，2001：3-4． [15]Kong J H, Zhen L, Guo B, et al.Influence of Mo content on microstructure and mechanical properties of high strength pipeline steel[J].Materials Design, 2004, 25(8):723-728