超快冷对厚规格X80管线钢组织性能的影响  

Effect of Ultra-Fast Cooling on Microstructure and Performance of Thick X80 Pipeline Steel

作　　者：牛涛[1] 吴新朗[2] 安成钢 姜永文[1] 张彩霞[2] 于晨[2] 代晓莉[1] 

机构地区：[1]首钢技术研究院,北京100043 [2]首钢股份公司迁安钢铁公司,迁安064404

出　　处：《材料研究学报》2016年第8期621-626,共6页Chinese Journal of Materials Research

摘　　要：采用Gleeble试验机研究了厚规格(22mm)X80管线钢的动态相变行为,得到了动态CCT曲线,对不同冷却工艺钢的显微组织、力学性能以及析出行为进行了系统的对比分析。结果表明,在40℃/s的高冷速条件下试验用钢的组织为细小的板条贝氏体(LB),相变终止温度达到约400℃;在超快冷工艺条件下钢卷的强度有所提高,韧性没有明显的变化;其显微组织中准多边形铁素体(QF)的比例下降,板条贝氏体(LB)的比例上升,M/A岛的比例有所降低;轧后快冷可抑制奥氏体中的析出,提高Nb在铁素体中的析出比例,使析出粒子尺寸更加细小,提高析出强化效果。Dynamic phase transformation behavior and CCT curves of 22 mm thick X80 pipeline steel were investigated using Gleeble simulator. Comparative analysis of microstructure, mechanical properties and precipitation behavior was carried out for the steel cooled by different ways. Results reveal that even under cooling rate of 40℃/s, the microstructure still consists of mainly the refined lath bainite（LB）, while the end phase of transformation temperature reaches about 400℃. The strength of coil increases without obvious change in toughness due to ultra fast cooling. The proportion of Quasipolygnoal ferrite（QF） reduces as well as M/A island, while that of lath bainite（LB） rises instead. Precipitation of Nb（C, N） has been inhibited by ultra fast cooling after rolling, which increases the proportion of precipitate in α-Fe with more refined particle size and promotes the precipitation strengthening effect.

关 键 词：金属材料 管线钢 超快冷 相变 组织 M/A岛 析出 

分 类 号：TG142.1[一般工业技术—材料科学与工程]