Study on Microstructure - Properties and Plastic Mechanism of A X80 Large Deformation Pipeline Steel
Gas and oil developments in cold areas and deep seas are steadily progressing.Accordingly,the construction of pipelines has expanded to the environmentally severe regions such as cold region,seismic region,deepwater and sour gas environment.Various material properties in addition to higher strength,such as toughness,deformation and sour resistant property,are required for recent linepipe steels.The present study in a laboratory indicate that a dual phase microstructure with bainite and M/A constituent was effective for simultaneously improving deformability and toughness instead of bainite single microstructure.X80 pipeline steel containing bainite and M/A constituent can be obtained by a novel HOP(heating on-line partitioning technology.Compared with traditional X80 pipeline steel,the(B+M/A)X80 pipeline steel has a similar strength and higher plasticity with the yield ratio of 0.80,uniform elongation of 10%and strain hardening exponent of 0.12,which meets the technical requirements of high deformability linepipe and is suitable for the environmentally severe regions such as permafrost and seismic regions.Microstructural analysis indicated that the synergistic effect of the tempered bainite and fine M/A component endowed experimental steel with higher strength-plasticity.Moreover,the precipitation of carbides and the formation of martensite lead to high strength of experimental steel.The excellent plasticity of experimental steel results from the tempered softening of bainite,the recovery of the dislocation and the formation of thin sheet-like or block-like retained austenite.
(B+M/A) X80 high deformability pipeline steel HOP Micarostructure and properties
MA Jing ZHANG Xiaoyong JIA Zhimin CHENG Shixia GAO Huilin
School of Materials Science and Engineering,Xi”an Shiyou University,Xi”an,Shaan”xi,China Department of quality management,AVIC Xi”an Aircraft Industry(GROUP)Company LTD,Xi”an,Shaan”xi,China School of Materials Science and Engineering,Xi”an Jiaotong University,Xi”an,Shaan”xi,China
国内会议
西安
英文
1-8
2015-04-27（万方平台首次上网日期，不代表论文的发表时间）