低焊接裂纹敏感性低碳贝氏体高强度钢板Q800CFE的研发  

Research and Development of Low Welding Sensitiveness Low Carbon Bainite High Strength Steel Q800CFE Plate

作　　者：刘丽华 

机构地区：[1]南京钢铁股份有限公司新产品研发推广中心,南京210035

出　　处：《特殊钢》2014年第2期51-53,共3页Special Steel

摘　　要：研发的25 mm Q800CFE钢板（/％：0.04～ 0.08C,0.20 ～0.50Si,1.50～1.80Mn,≤0.015P,≤0.005S,0.015～0.060Nb,≤0.30Mo,≤0.03Ti,0.0008～0.003 0B;裂纹敏感性指数≤0.23）的冶金流程为铁水预处理-120 t转炉-LF-RH-220 mm CC-轧制工艺.成品板终轧≤850℃,水冷至≤400℃,冷却速度20～30℃/s,并进行530 ～635℃回火处理.测试了Q800CFE钢板的动态连续冷却转变（CCT）曲线,研究了回火温度对组织和力学性能的影响,以及试验了该钢的焊接性能.结果表明,随回火温度增加,板条组织尺寸增大;在530℃回火时,Q800CFE钢板具有较优的力学性能,抗拉强度≥900 MPa、伸长率≥15％,-40℃夏比冲击功≥100 J;25 mm板室温下预热75℃焊接接头即可防止产生冷裂纹.The metallurgical flow sheet of developed 25 mm Q80OCFE steel plate （/%： 0. 04 - 0. 08C, O. 20 - 0. 50Si, 1.50 - 1.80Mn, ≤0. 015P, ≤0. 005S, 0. 015 -- 0. 060Nb, ≤0. 30Mo,≤0. 03Ti, 0. 000 8 - O. 003 OB ; crack sensitivity index ≤0. 23 ） is metal pretreatment-120 t BOF-LF-RH-220 mm CC-rolling process. Finishing plate rolling tem- perature is ≤850 ℃ , water cooling to ~〈400 ℃ with cooling rate 20 -30 ℃/s, and tempering treatment is carried out at 530 - 535 ℃. The dynamic continuous cooling transformation （CCT） curves of QS00CFE steel plate is measured and the effect of tempering temperature on structure and mechanical properties and the wielding behavior of steel plate are studied. Results show that with increasing tempering temperature the size of lath structure increases ; with tempering at 530 ℃, the QSOOCFE steel plate has optimum mechanical properties, its tensile strength t〉900 MPa, elongation ≥15% , -40 ℃ Charpy impact energy 1〉100 J; and the cold crack in weld joint shall be avoided as the ambient 25 mm plate is preheated to 75 ℃. Material Index Low Carbon Bainite High Strength Steel QSOOCFE, Quenching in Line, Tempering, Structure, Me- chanical Properties, Wielding Behavior

关 键 词：低碳贝氏体高强度钢Q800CFE 在线淬火 回火 组织 力学性能 焊接性能 

分 类 号：TG142.4[一般工业技术—材料科学与工程]