作　　者： ; ;

机构地区： 东北大学材料与冶金学院轧制技术及连轧自动化国家重点实验室

出　　处： 《材料研究学报》 2008年第3期279-286,共8页

摘　　要： 在低碳钢和低碳加铌、钒、钛微合金钢中,通过马氏体冷轧-回火的方法获得了尺寸为数百纳米的超细晶粒铁素体组织,研究了超细晶粒组的形成机制和热稳定性.通过马氏体相变在这些钢中引入了大量高密度位错,马氏体冷轧后位错进一步增殖,形成大量位错胞状结构;在500-600℃进行的60 min回火将上述胞状结构转变成具有清晰大角晶界的超细晶粒.在回火过程中形成的微合金元素碳化物对位错运动和晶界移动具有有效的"钉扎"作用,有助于获得超细晶组织并明显提高其热稳定性. Ultrafine ferrite grains with sizes about several hundred nanometers were obtained through tempering the cold rolled martensite in a low carbon and in a microalloyed steel bearing Nb, V and Ti. The mechanism for the formation of the ultrafine grained microstructure was discussed. Lots of highdensity dislocations were introduced through martensite transformation and more dislocations are stored through cold rolling, forming into dislocation cell structures. Dislocation cell structures were developed into ultrafine ferrite grains with sharp and large misoriented boundaries during tempering at temperatures from 500℃ to 600℃ for 60 rain. During the tempering process, microalloying precipitates formed and effectively pinned the dislocation movement and the migration of the grain boundaries. As a result, the thermal stability of the ultrafine grained microstructure is improved.

关 键 词： 金属材料 超细晶 冷轧马氏体 回火 微合金钢

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]