摘要
采用轧后空冷＋超快速冷却的方式，研究了开冷温度对热轧铁素体／贝氏体（F／B）双相钢组织性能的影响。结果表明：开冷温度显著影响F／B双相钢的显微组织和性能。开冷温度由747℃降至700℃时，铁素体体积分数由17．3％增至85．7％，铁素体晶粒尺寸由3．3μm粗化至3．6μm，贝氏体中析出的碳化物含量增加。同时，F／B双相钢的屈服强度从594MPa降至475MPa，抗拉强度从648MPa降至532MPa，伸长率从17．7％升至34．3％，扩孔率从36．4％提高至82．8％。因此，为实现热轧F／B双相钢力学性能和扩孔性能的平衡，开冷温度应控制在730～700℃。
The process of air-cooling follawed by ultra fast cooling after hot-rolled was used to investigate the effects of start cool- ing temperature （SCT） on the microst：mcture and mechanical properties of a hot-rolled ferrite/bainite （F/B） dual-phase steel. The results showed that the microstructure and properties of the F/B dual phase steels were influenced by SET obviously. The volume fraction of ferrite phase was increased from 17.30% to 85.70% , the grain size of ferrite size was increased from 3.3 μm to 3.6 μm and the precipitated carbide in bainite was also increased with the SCT decrease from 747 ℃ to 700 ℃. At the same time, lowering SCT from 747℃ to 700 ℃ , the yield strength of this steel was reduced down to 475 MPa from 594 MPa, the tensile strength down to 532 MPa from 648 MPa , the elongation up to 34.30% from 17.70% and the hole expansion ratio up to 82.8% from 36. 4%, respectively. So, the start cooling temperature should be in 730--700 ℃ to balance the strength and the deformation properties of the hot-rolled F/B dual phase steels.
出处
《轧钢》
2015年第6期5-7,11,共4页
Steel Rolling
基金
教育部重大科技创新项目(N120807001)
国家自然科学基金青年项目(51204049)
关键词
热轧F/B双相钢
NG-TMCP
开冷温度
显微组织
力学性能
扩孔性能
hot-rolled F/B dual phase steels
new-generation thermo-mechanical control process （NG-TMCP）
start cooling tem-perature
microstructure
mechanical Iz,roperties
hole expansion property
