加速冷却对X70钢热影响区组织与韧性的影响  

EFFECT OF ACCELERATING COOLING ON MICROSTRUCTURE AND TOUGHNESS OF HAZ OF X70 PIPELINE STEEL

作　　者：于少飞[1] 钱百年[1] 国旭明[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016

出　　处：《金属学报》2005年第4期402-406,共5页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展规划资助项目G1998061511

摘　　要：根据加速冷却对TMCP钢组织与性能的影响,提出在X70管线钢焊接过程中以加速冷却方式改善热影响区韧性的方 法.热模拟及实际焊接接头实验结果表明:适当提高冷速后,热影响区贝氏体基体中高碳高硬度的M-A组元明显减少,并被韧性 的残余奥氏体薄膜所取代;而在喷水冷却的高冷速下得到了粗大贝氏体束组织,韧性反而没有改善.选择适当的冷却速度,使热影 响区获得韧性良好的中温转变组织,是提高管线钢热影响区韧性的简单而有效的途径.Based on the effect of accelerating cooling on the microstructure and properties of thermo-mechanical control process (TMCP) steel, we proposed to adopt this method for improvement of heat affect zone (HAZ) toughness of X70 pipeline steel. The results of simulated experiment and actual weldment indicate that at appropriate accelerating cooling rate the M-A constituent in HAZ is reduced obviously in amount and replaced by tough austenite films. Coarse bainitic sheaves were obtained when jetting water directly to the sample and the toughness is not improved. Accelerating cooling with appropriate cooling rate is a simple and efficient method to improve the HAZ toughness.

关 键 词：管线钢 加速冷却 奥氏体薄膜 贝氏体 热影响区 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG406[金属学及工艺—金属材料]