Nb微合金化对热轧700 MPa超高强耐候钢组织和性能的影响  

Effect of Nb microalloying on Structure and Properties of Hot-Rolled 700 MPa Super-High Strength Weathering Steel

作　　者：赵培林[1,2] 孙新军[1] 汤化胜[2] 雍岐龙[1] 

机构地区：[1]钢铁研究总院结构材料研究所,北京100081 [2]莱芜钢铁集团有限公司技术中心,莱芜271104

出　　处：《特殊钢》2012年第1期46-50,共5页Special Steel

摘　　要：试验超高强耐候钢(/%:0.062～0.065C、0.29～0.30Si、1.23～1.27Mn、0.49～0.52Cr、0.19～0.20Ni、0.29～0.31Cu、0～0.20Mo、0.035～0.060Nb)由50kg真空感应炉熔炼,在实验室锻成60mm×60 mm方坯并热轧成4 mm板材,末道次温度880℃,水冷至600℃炉冷。用光学显微镜、扫描电镜、透射电镜和万能拉伸试验机研究了Nb和Nb-Mo微合金化对该钢组织和力学性能的影响。试验结果表明,0.060%Nb钢较0.035%Nb钢晶粒更细,强度提高～70 MPa,但伸长率相同;与未加Mo的0.035%Nb和0.060%Nb钢相比,0.035%Nb-O.20%Mo钢M/A相明显增加,并出现大量贝氏体组织,抗拉强度增加,但屈强比和伸长率降低。The test super-high strength weathering steel （/% ： 0. 062 - 0. 065C, 0. 29 - 0. 30Si, 1.23 - 1.27Mn, 0. 49 -0. 52Cr, 0. 19 -0. 20Ni, 0. 29 -0. 31Cu, 0 -0. 20Mo, 0. 035 -0. 060Nb） is mehed by a 50 kg vacuum induction furnace, forged to 60 mm × 60 mm billet, then hot rolled to 4 mm plate in laboratory by finishing rolling pass at 880 ℃ , water cooling to 600 ℃ , furnace cooling. The effet of Nb and Nb-Mo microalloying on structure and mechanical properties of steel are studied by optical, scanning electron and transmission electron microscope, and universal tensile testion ma- chine. Test results show that as compared with 0. 035% Nb steel the grain size of 0. 060% Nb steel is more finer, the strength increases by -70 MPa, but the elongation is the same as that of 0. 035Nb steel; as compared with non added Mo steel （0. 035Nb steel and 0. 060% Nb steel） the M/A phases in 0. 035% Nb-0. 20% Mo steel increase obviously and bainite structure occurs in steel led to increase of tensile strength and decrease of yield-strength ratio and elongation of steel.

关 键 词：NB微合金化 超高强耐候钢 组织 力学性能 析出相 

分 类 号：TG335.11[金属学及工艺—金属压力加工]