铁塔用460 MPa级大型角钢的组织与性能
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摘要
由于总压下量较小,铁塔用大型角钢的强度和韧性往往偏低。以钒和氮微合金化能提高大型角钢的力学性能及其在不同部位的均匀性。检测了35 mm厚的25号角钢边部和角部的力学性能及显微组织。结果表明:角钢不同部位均达到了460 MPa级的屈服强度,-40℃的冲击吸收能量大于40 J;边部晶粒度约为9级,角部晶粒度约为7. 5级,角部析出相数量比边部多,从而减小了由于晶粒度差异造成的边部与角部之间的强度差异。
The heavy angle steel used for tower exhibits frequently insufficient strength and toughness because of its less total reduction. The mechanical properties and their homogeneity in different positions may be improved by microalloying with both vanadium and nitrogen for the heavy angle steel. The mechanical properties and microstructure in edge and corner of 35 mm thick angle steel No. 25 were examined. The results showed that the different positions of the angle steel all reached 460 MPa grade of yield strength and impact absorption energy at-40 ℃ as high as more than 40 J,and that grain sizes were about No. 9 in the edge and No. 7. 5 in the corner,and precipitated phase in the corner was more than that in the edge,thus reducing differnce between the edge and the corner in strength due to their different grain sizes.
The heavy angle steel used for tower exhibits frequently insufficient strength and toughness because of its less total reduction. The mechanical properties and their homogeneity in different positions may be improved by microalloying with both vanadium and nitrogen for the heavy angle steel. The mechanical properties and microstructure in edge and corner of 35 mm thick angle steel No. 25 were examined. The results showed that the different positions of the angle steel all reached 460 MPa grade of yield strength and impact absorption energy at-40 ℃ as high as more than 40 J,and that grain sizes were about No. 9 in the edge and No. 7. 5 in the corner,and precipitated phase in the corner was more than that in the edge,thus reducing differnce between the edge and the corner in strength due to their different grain sizes.
引文
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[2]陈亮,冯运莉,李杰,等.铁塔用Q420B大规格角钢的组织与性能研究[J].热加工工艺,2016,45(20):101-103.
[3]柴锋,苏航,杨才福,等. V-N微合金化高强度铁塔用角钢的研究[J].钢铁研究学报,2010,22(11):39-44.
[4]王元清,廖小伟,张子富,等.输电线铁塔钢材的低温力学和冲击韧性试验[J].哈尔滨工业大学学报,2015,47(12):70-74.
[5]余朝胜.高压输电线路大规格高强角钢铁塔应用研究[J].电力与电工,2012,32(2):18-20.
[6]许鹤君,凌霄,巴发海.风力发电机主轴用34CrNiMo6钢的韧脆转变温度分析[J].理化检验-物理分册,2015,51(5):307-311.
[7]方芳,雍岐龙,杨才福,等. V(C,N)在V-N微合金钢铁素体中的析出动力学[J].金属学报,2009,45(5):625-629.
[8]李麟,许珞萍.钢中铌钒碳氮化合物的析出及其稳定性分析[J].上海金属,2005,27(2):1-3.
[9]顾俭,陈洁.钒氮微合金钢生产热轧Ⅲ级钢筋[J].上海金属,2005,27(2):29-32.