焊管2011，Vol.34Issue(6)：14-19,6.
X80钢的热处理组织和性能研究
Study on Heat Treatment Microstructure and Mechanical Properties of X80 Steel
摘要
Abstract
The heat treatment microstmcture and properties of X80 steel were analyzed by means of structure analysis, mechanical properties test and fracture analysis. The results showed fine and well-proportioned austenitic grain is obtained, when X80 steel is heated at 950 ℃, 950 ℃ is applicable quenching temperature for X80 steel.The microstructure of X80 steel is bainite ferrite (BF) + granular bainite (GB) when steel is tempered at 550 ℃and 600 ℃, partial ferrite laths in BF merge and broaden, the interior sub-lath boundary in GB begin to merge and disappear, and the MIA constituent (a mixture of martensite plus retained austenite) in GB is orbicular, at the two tempering temperature the X80 steel shows a certain degree of tempering stability. The microstructure of X80 steel is GB + quasi-polygonal ferrite (QF) after 650 ℃ tempering, the original BF laths merge to form smaller GB crystal grains, it is the reason that the steel shows good combination of strength and toughness. The microstructure of X80 steel is mainly QF after 700 ℃ tempering, which can cause serous reduction of yield strength. The M/A constituent assemble and grow up in the grain boundary of QF, which cause worse low-temperature toughness for X80 steel.关键词
X80钢/微观组织/热处理/回火温度/力学性能Key words
X80 steel/ microstructure/ heat treatment/ tempering temperature/ mechanical property分类
矿业与冶金引用本文复制引用
牛靖,刘迎来,张骁勇,吉玲康,冯耀荣,张建勋..X80钢的热处理组织和性能研究[J].焊管,2011,34(6):14-19,6.基金项目
中国石油天然气集团公司重大科技专项(6990-HT-XEX-03-(2008)-0137) （6990-HT-XEX-03-(2008）
