控制冷却下强冷及返温阶段板坯表面热塑性及组织形貌变化规律  

Variation of Hot Ductility and Microstructure Morphology of Slab Surface During Period of Intensive Cooling and Reheating Under Controlled Cooling

作　　者：赵新宇[1] 刘洋[1] 甄新刚[2] 王海宝[1] 王文军[1] 邹扬[1] 

机构地区：[1]首钢技术研究院,北京100043 [2]首秦金属材料有限公司,河北秦皇岛066326

出　　处：《钢铁》2013年第7期32-35,39,共5页Iron and Steel

摘　　要：制作直径10mm试样模拟铸坯表面,使用Gleeble-2000D热模拟试验机研究表面控制冷却下强冷和返温阶段板坯表面热塑性及组织形貌的变化规律,为表面组织控制冷却在立弯式板坯连铸机上的应用提供理论依据。研究结果表明:强冷阶段,魏氏组织和膜状先共析铁素体的形成造成试样塑性恶化。返温阶段,返温处理有效地消除了这种恶化,将试样断面收缩率最小值提高至40%以上。因此表面控制冷却在立弯式连铸机上应用时,强冷阶段应在铸坯进入弯曲段之前完成,铸坯可以在返温阶段进入弯曲段。The samples of diameter 10 mm were made to simulate slab surface.The variation of hot ductility and microstructure morphology of slab surface during the period of intensive cooling and reheating treatment under surface structure controlled cooling was studied with the Gleeble-2000D hot simulation tester.The theoretical basis will be provided to apply on vertical bending caster of surface structure control cooling.The results show that： the hot ductility of the samples is deteriorated because of the form of widmanstatten structure and film-like proeutectoid ferrite along grain boundary during the period of intensive cooling.However,the treatment of reheating can effectively eliminate the deterioration of hot ductility producing during the period of intensive cooling,which makes the reduced area of the samples increasing to over 40%.Therefore,the treatment of intensive cooling should be accomplished before the slab enters the segment of bending.The slab can enter the bending segments during the period of reheating when the controlled cooling is applied on vertical bending caster.

关 键 词：表面组织控制冷却 强冷 返温 高温热塑性 金相组织 

分 类 号：TG245[金属学及工艺—铸造]