卷取温度对热轧F/B双相钢组织性能的影响  

Effects of Coiling Temperature on Microstructure and Mechanical Properties of Hot-Rolled Ferrite /Bainite Dual Phase Steel

作　　者：沈鑫珺 裴新华[1,2] 唐帅[1] 王国栋[1] 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819 [2]上海梅山钢铁公司技术中心,江苏南京210039

出　　处：《东北大学学报（自然科学版）》2014年第8期1120-1123,共4页Journal of Northeastern University(Natural Science)

基　　金：中央高校基本科研业务费专项资金资助目(N120807001);国家自然科学基金资助项目(51204049)

摘　　要：采用轧后空冷＋超快速冷却工艺，研究卷取温度对热轧铁素体／贝氏体（F／B）双相钢组织性能的影响规律．结果表明：卷取温度由504℃降至250℃时，铁素体体积分数变化很小（85．7％-87．8％），铁素体晶粒尺寸变化也很小（3．6-3．7μm），组织中的硬相由以贝氏体为主转变为以马氏体为主；实验钢的抗拉强度由510MPa升至597MPa，屈服强度由475MPa降至389MPa，延伸率变化较小（32．2％～35．0％）．另外，随着卷取温度的降低，铁素体与贝氏体或马氏体间的变形协调能力降低，使扩孔过程中微孔提前形核，同时加快了已有微孔的长大及合并过程，导致试样发生的塑性变形减小，扩孔性能降低，扩孔率由101．4％降至52．4％．The process of air-cooling followed by ultra fast cooling after hot-rolling was used to investigate the effects of coiling temperature on the microstructure and mechanical properties of a ferrite/bainite （F/B） dual phase steel. The results show that the volume fraction and the grain size of ferrite are in the rage of 85.7% - 87.8% and 3.6 - 3.7 μm, respectively, almost independent of the coiling temperature. Lowering coiling temperature from 504 ℃to 250 ℃, the dominant hard phase was transformed from bainite to martensite, resulting in the ultimate strength up to 597 MPa from 510 MPa, the yield strength down to 389 MPa from 475 MPa, but the elongation without significant change （32. 2% -35. 0% ）. Besides, the deformation compatibility between ferrite and bainite or martensite is weakened with the decrease of the coiling temperature, which induces the nucleation in advance, accelerates growth and coalescence of micro-voids, so the hole expansion property is deteriorated and the hole expansion ratio is reduced from 101.4% to 52. 4%.

关 键 词：热轧F B双相钢 新一代控制轧制和控制冷却 超快速冷却 卷取温度 组织演变 力学性能 扩孔性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]