Strength, strain capacity and toughness of five dual-phase pipeline steels  

作　　者：Yi Ren Xian-bo Shi Zhen-guo Yang Yi-yin Shan Wei Ye Gui-xi Cai Ke Yang 

机构地区：[1]State Key Laboratory of Metal Material for Marine Equipment and Application,Anshan 114009,Liaoning,China [2]CAS Key Laboratory of Nuclear Materials and Safety Assessment,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China [3]Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China

出　　处：《Journal of Iron and Steel Research International》2021年第6期752-761,共10页

基　　金：financially supported by the National Key Research and Development Program of China(Grant Nos.2017YFB0304901,2018YFC0310302 and 2018YFC0310304);State Key Laboratory of Metal Material for Marine Equipment and Application Funding(Grant No.SKLMEA-K201901);the Doctoral Scientific Research Foundation of Liaoning Province(Grant No.20180540083).

摘　　要：The effect of microstructures on strength,strain capacity and low temperature toughness of a micro-alloyed pipeline steel was elucidated.Five various dual-phase microstructures,namely,acicular ferrite and a small amount of(around 2 vol.%)polygonal ferrite(AF+PF),polygonal ferrite and bainite(PF+B),polygonal ferrite and martensite/austenite islands(PF+M/A),polygonal ferrite and martensite(PF+M)and elongated polygonal ferrite and martensite(ePF+M),have been studied.Experimental results show that AF+PF microstructure has high yield strength and excellent low temperature toughness,whereas its yield ratio is the highest.Polygonal ferrite-based dual-phase steels,PF+B,PF+M/A and PF+M microstructures show better strain capacity and low temperature toughness.The strain capacity and low temperature toughness of ePF+M microstructure are the worst due to its high strength.The relationship between microstructure,strength,strain capacity and toughness has been established.Based on the results,the optimum microstructure for a better combination of strength,strain capacity and toughness is suggested to be the one having appropriate polygonal ferrite as second phase in an acicular ferrite matrix.

关 键 词：Pipeline steel Dual-phase microstructure STRENGTH Strain capacity TOUGHNESS 

分 类 号：TG457.11[金属学及工艺—焊接]