基于临界区加速冷却的(B+F)X80大变形管线钢的组织和性能研究  

Study on Microstructure and Properties of(B+F) X80 Large Deformation Pipeline Steel After Critical Zone Accelerated Cooling

作　　者：马晶[1] 张骁勇[1] 程时遐[1] 高惠临[1] 

机构地区：[1]西安石油大学材料科学与工程学院,西安710065

出　　处：《材料导报》2014年第2期118-122,共5页Materials Reports

基　　金：国家自然科学基金(51174165)

摘　　要：采用热模拟、力学性能测试和材料显微分析等试验技术,对X80管线钢在临界区加速冷却工艺下的组织性能变化规律进行了研究。结果表明,通过临界区加速冷却,X80管线钢可获得贝氏体+铁素体(B+F)双相组织。随着始冷温度的上升,试验钢的贝氏体含量增加,铁素体含量降低,导致屈服强度增高,塑性降低。当始冷温度为840℃时,显微组织以细小、多位向分布的贝氏体为主,辅以高密度位错的多边形铁素体。这种(B+F)双相组织使得试验钢的屈强比为0.80、均匀伸长率为10.0%、形变强化指数为0.12,满足了大变形管线钢的技术要求。The relationship between microstructures and properties of X80 pipeline steel after the critical zone accelerated cooling was investigated through thermal simulation,mechanical property test and microscopic analysis method.The results show that （B＋F） dual-phase microstructure can be obtained by critical zone accelerated cooling.With the increasing of starting cooling temperature,content of bainite increases and content of ferrite decreases,which lead to increase of yield strength and reduce of plasticity.When starting cooling temperature is 840 ℃,the microstructure of the experimental steel mainly consists of fine lath bainite and ferrite with high dislocation density.This （B＋F）dual-phase structure makes the yield ratio of 0.80,uniform elongation of 10% and strain hardening index of 0.12 for the experimental steel,which meets the technical requirements for large deformation.

关 键 词：X80大变形管线钢 临界区加速冷却 始冷温度 

分 类 号：TG142.1[一般工业技术—材料科学与工程]