Effect of Ti-enriched Carbonitride on Microstructure and Mechanical Properties of X80 Pipeline Steel  

作　　者：Wei Deng,Xiuhua Gao,Dewen Zhao,Linxiu Du,Di Wu and Guodong Wang State key laboratory of rolling and automation,Northeastern University,Shenyang 110819,China 

出　　处：《Journal of Materials Science & Technology》2010年第9期803-809,共7页材料科学技术（英文版）

基　　金：the financial supports from the Fundamental Research Funds for the Central Universities(No.N090607002);the National Natural Science Foundation of China(No.51074052)

摘　　要：In this study,two API X80 pipeline steels were fabricated by varying Ti additions,and their microstructures and fracture characteristics were analyzed to investigate the effects of Ti-enriched carbonitride on the tensile properties and Charpy impact properties.Lathy bainite,a mass of matensite/austenite（M/A）,coarse cubic Ti-enriched inclusions,chain-typed Ti-enriched precipitations,weak toughness and high tensile strength were found as consequences of higher amount of Ti content.Those large scale and chain-typed Ti-enriched carbonitrides are one kind of crack sources during fracture.The negative effect of higher amount of Ti on the impact properties is increased with decreased temperature.In this study,two API X80 pipeline steels were fabricated by varying Ti additions,and their microstructures and fracture characteristics were analyzed to investigate the effects of Ti-enriched carbonitride on the tensile properties and Charpy impact properties.Lathy bainite,a mass of matensite/austenite（M/A）,coarse cubic Ti-enriched inclusions,chain-typed Ti-enriched precipitations,weak toughness and high tensile strength were found as consequences of higher amount of Ti content.Those large scale and chain-typed Ti-enriched carbonitrides are one kind of crack sources during fracture.The negative effect of higher amount of Ti on the impact properties is increased with decreased temperature.

关 键 词：X80 pipeline steel Ti-enriched carbonitride Matensite/austenite（M/A） constitute Impact toughness 

分 类 号：TG142.7[一般工业技术—材料科学与工程]