摘要
对一种低碳锰钢进行了终轧温度高于Ar3卷取温度的不同控轧控冷处理．扫描电镜和透射电镜观察表明,终轧变形在奥氏体再结晶区进行时,有利于获得均匀分布的铁素体和一定含量的贝氏体组织．终轧温度降低到800℃,实验钢产生了形变诱导铁素体相变．当冷速增加到60℃／s且卷取温度为400℃左右时,铁素体主要沿原奥氏体晶界分布,晶粒得到细化,贝氏体体积分数增加,强度有较大的提高,但延伸率较低,屈强比较高．通过控制终轧温度为800-850℃、冷速为40℃／s左右以及卷取温度为550℃左右时,低碳锰钢可以获得仿晶界型铁素体／贝氏体的复相组织,其中铁素体晶粒尺寸为8—8．5μm,贝氏体体积分数在30％左右,综合性能较好．
Thermo-mechanical controlled process （TMCP） experiments with finish-rolling temperatures （FRT） higher than Ar3 and different coiling temperatures （CT） have been carried out on a low carbon manganese steel. SEM and TEM observations indicated that the finish-rolling deformation performed in the austenite recrystallization region can obtain a microstructure consisting of uniformly distributed ferrite and a certain amount of bainite. Deformation induced ferrite transformation （DIFT） occurred when the FRT decreased to 800℃. Adoption of an accelerated cooling rate of 60℃/s and a coiling temperature of 400℃ would promote ferrite distribution along prior austenite grain boundaries, thus making the allotriomorphic ferrite grain refined; meanwhile, the resultant increase in volume fraction of bainite would lead to strength increasing and elongation decreasing, but high yield ratio （σs/σb）. The good combination of mechanical properties of the steel with grain boundary allotriomorphic ferrite/bainite duplex microstructures could be gained by controlling FRT （800-850℃）, cooling rate （40℃ /s） and CT （550℃）, in which ferrite grain size was about 8-8.5μm and the volume fraction of bainite about 30%.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第11期1227-1232,共6页
Acta Metallurgica Sinica
基金
国家自然科学基金
宝钢集团公司联合资助项目50271015~~
关键词
低碳锰钢
终轧温度
形变诱导铁素体相变
贝氏体
力学性能
low carbon manganese steel, finish-rolling temperature, deformation induced ferrite transformation, bainite, mechanical property
