X70管线钢连续冷却过程中的相变行为  

Continuous cooling transformation behavior of X70 pipeline steel

作　　者：冯运莉[1] 童辉[1] 尹金枝[1] 陈礼斌[2] 

机构地区：[1]河北理工大学金属材料工程系,河北唐山063009 [2]唐山钢铁有限公司技术中心,河北唐山063016

出　　处：《金属热处理》2010年第2期39-42,共4页Heat Treatment of Metals

基　　金：唐山市科学技术研究与发展计划项目(04204501C-22)

摘　　要：利用Gleeble-3500热模拟机研究了X70管线钢未变形和经双道次变形后连续冷却过程的相变行为,采用热膨胀法结合金相法建立了静态和动态连续冷却转变曲线,分析了冷却速度和变形参数对组织转变的影响规律。结果表明,热变形加速针状铁素体和多边形铁素体相变,使相变的开始温度和结束温度显著提高,CCT曲线明显向左上方移动。实际中为获得针状铁素体组织,需相应增加变形后的冷却速度。与同一冷速下未经变形的连续冷却转变的组织相比,热变形可以显著细化组织,使组织中的岛状物更加细小弥散,通过变形可以在更宽的冷速范围内获得针状铁素体。The continuous cooling transformation behaviors were researched on X70 pipeline steel through two pass deformation and non-deformed austenite using Gleeble-3500 thermal mechanical simulator,and static continuous cooling transformation curve and dynamic continuous cooling transformation curve were measured through thermal dilation method and metallographic method.The influence of cooling rate and deformation parameters on microstructure was analyzed.The results show that the hot deformation accelerates the acicular ferrite and polygonal ferrite phase transformation,increases the starting transformation temperature and the finishing transformation temperature significantly,and shifts the CCT curve moving upward to the left side corner.Acicular ferrite is obtained in practice using accelerated cooling rate after deformation.Acicular ferrite can be obtained in wider range of cooling rates,and microstructure and island structure is finer through hot deformation.

关 键 词：X70管线钢 相变 针状铁素体 控制冷却 

分 类 号：TG142.1[一般工业技术—材料科学与工程]