不同冷却制度下X100管线钢组织特征及力学性能

来源期刊：钢铁2011年第2期

论文作者：周民 杜林秀 刘相华

文章页码：74 - 80

关键词：显微组织； 力学性能； 弛豫； 超快冷

Key words：microstructure； mechanical property； relaxation； super-fast cooling process

摘    要：采用热模拟试验机和试验轧机研究了X100管线钢连续冷却相变规律及不同冷却制度下显微组织特征及力学性能变化规律。研究结果表明:随冷却速度升高及终冷温度降低,试验钢显微组织由针状铁素体过渡至板条贝氏体及马氏体,非淬火条件试验钢中马氏体岛或M-A岛为微孪晶马氏体;轧制后直接以30℃/s冷却至450℃左右时,试验钢具有良好强韧性,采用弛豫及超快冷工艺时,需控制弛豫时间以及超快冷结束温度并与随后的冷却工艺相结合,方可获得理想的显微组织及良好的强韧性。

Abstract: With a thermal simulator and a laboratory mill,the continuous cooling transformation(CCT) and the microstructure characteristic and mechanical properties of a lab designed pipeline steel in different cooling schedules were studied.It is shown that with cooling rate increasing and finish cooling temperature decreasing,the microstructure evolved from acicular ferrite to lath bainite and martensite,martensite islands or M-A islands are micro-twining martensite in non-quenched steel,the comprehensive mechanical properties is the optimum in the steel that cooled to about 450 ℃ at the rate of about 30 ℃/s without relaxation.When relaxation and super-fast cooling process are used,it is essential to well control the relaxation time and finish cooling temperature of super-fast cooling process and combine with the following cooling process for obtaining the perfect microstructure and strength and toughness.