高温变形对X100级管线钢相变规律影响  

Effect of high temperature deformation on phase transformation of X100 grade pipeline steel

作　　者：余万华[1] 翟士斌 胡亚伟[1] 席常亮 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《材料热处理学报》2015年第8期155-160,共6页Transactions of Materials and Heat Treatment

摘　　要：采用热模拟技术对X100管线钢在连续冷却转变下的显微组织的变化规律进行了研究。深入讨论了X100管线钢的CCT曲线及其在不同冷却条件下的相变规律。结果表明,X100管线钢的组织为GB（Granular Bainite）、QF（Polygonal Ferrite）、M/A构成的复相组织,且各相比例和形态对性能影响较大。发现随着冷却速度的提高,在连续冷却转变组织中依次出现多边形铁素体（QF）、粒状贝氏体（GB）、贝氏体铁素体（BF）、板条马氏体（LM）。静态CCT在5~20℃/s冷速区间可得到GB、BF、M/A构成的复相组织,动态CCT的冷却速度大于20℃/s才能得到相应的组织。研究结果表明：高温变形能够扩大相变温度区间,细化相变后晶粒尺寸。高温变形对铁素体相变影响较大,而对贝氏体相变影响较小。Microstructure of X100 high strength pipeline steel during continuous cooling was investigated by means of thermal simulation technique on a Gleeble-3800 simulator. The CCT curves and the phase transformation behavior of the steel at different cooling conditions were investigated. Results show that the X100 pipeline steel is a multi-phase steel, for which the microstructure is mainly consists of granular bainite（GB）, polygonal ferrite （QF） and martensite-austensite （M/A）. The morphology and proportion of the phases have significant influence on the performances of the X100 steel. The microstructure of the steel changes from polygonal ferrite, granular bainite （GB） , bainite ferrite（BF） to lath martensite（LM） with cooling rate increasing. The multi-phase microstructure with GB, BF and M/A phases can be obtained under the cooling rate of 5-20 ℃/s for static CCT curves, and under the cooling rate faster than 20 ℃/s for the dynamic CCT curves, respectively. The deformation at high temperature can broaden the range of the phase transformation temperature, refine grain size of the steel. High temperature deformation can significantly influence the ferrite transformation, but slightly to the bainite transformation.

关 键 词：X100管线钢 热模拟技术 显微组织 复相 

分 类 号：TG162.8[金属学及工艺—热处理]