含Nb钢变形后长时间等温对析出的影响  

Effect of long-time isotherm after deformation on precipitation in Nb-bearing steel

作　　者：苑少强[1] 梁国俐[1] 张晓娟[1] 刘义[2] 

机构地区：[1]唐山学院科研处,河北唐山103000 [2]唐钢集团技术中心,河北唐山063016

出　　处：《辽宁工程技术大学学报（自然科学版）》2009年第3期467-469,共3页Journal of Liaoning Technical University (Natural Science)

基　　金：河北省自然科学基金---钢铁联合研究基金资助(E2008001141)

摘　　要：运用热模拟技术,通过硬度测量及透射电镜(TEM)观察,分析了含Nb微合金钢奥氏体变形后长时间等温对低温(525℃)回火组织及析出行为的影响。结果表明:回火1200min时组织几乎保持不变。硬度值在回火初期一直下降,到120min后,开始缓慢回升,到1200min基本保持不变。应变诱导析出颗粒粗化后即使长时间回火,颗粒并没有明显长大。回火后期的硬度值上升是由于Nb在α相中进一步形核长大造成的。The variations of microstructure and precipitation behavior during tempering at 525℃ for long-time isotherm in deformed Nb-beafing microalloyed steel are investigated by means of thermo-simulation, hardness measurement, and the observation using transmission electron microscopy （TEM）. Experimental results indicate that the microstructure remains nearly unchanged until tempering for 1200min. The hardness decreases gradually until water-quenching tempering for 120min and then the hardness increases continuously until 1200min. When strain-induced precipitates are coarsened in deformed austenite, the grain size is almost no changes even with long-time tempering. With further precipitates, Nb nucleates in α phase and contributes to the increase of hardness.

关 键 词：等温保持 NB微合金钢 回火 析出 

分 类 号：TG113.25[金属学及工艺—物理冶金]