重载铁路用钢轨气压焊工艺研究

发布时间：2018-07-02 10:01

本文选题：重载铁路 + U78CrV　；参考：《西南交通大学》2017年硕士论文

【摘要】：重载铁路承担着运输大宗货物和煤等物质的重任,随着货运量不断增大,对钢轨承载能力要求也越来越高,强度高、耐磨性好的钢轨运用前景广阔。为获得优质焊接接头,最大限度地保障线路安全和长寿命,依赖于钢轨焊接方法、工艺选择和设备控制水平高低。因此使用具有我国完全自主知识产权的YHGQ-1200气压焊轨车,系统开展重载铁路钢轨气压焊接技术研究,对于提高重载铁路焊接水平具有不可估量的实用价值。本文首次采用GPW-1200(75)气压焊机,开展了 75kg/m U78CrV钢轨焊接工艺试验研究。采用YHGQ-1200气压焊轨车和相同焊轨工艺,完成了 60kg/m U78CrV和U75V钢轨焊接质量研究。同时,对PG5、贝氏体新型钢轨焊接工艺进行了初探,为今后PG5和贝氏体钢轨上重载线路的焊接应用提供了参考数据。结果表明:(1)75kg/mU78CrV热轧钢轨+热处理态钢轨的混焊试验成功,获得了接头冲击功15.8J、抗拉强度1005MPa、断后延伸率9.0%、轨顶面硬度HJ/Hp值在[1.06,1.09]区间,接头硬度相当于母材硬度,晶粒度在7级以上的接头质量,完全满足标准TB/T1632-2014《钢轨焊接》对接头质量的要求。(2)60kg/m U78CrV和U75V钢轨气压焊接发现:U78CrV(热处理态)钢轨焊接接头落锤、静弯、疲劳性能稳定,但焊后正火若不采用强制喷风冷却工艺,其接头硬度偏低,不满足标准要求;U75V(热轧态)钢轨接头质量完全符合TB/T1632标准,其接头轨顶面硬度HJ/HP值大于1.0,与母材硬度相当,表明可以从源头上减少重载线路焊接接头马鞍型磨耗病害。获得的气压焊工艺是一套既能够焊接60kg/mU78CrV(热轧态和热处理态)钢轨,又能焊接60kg/m U75V(热轧态)钢轨的相对宽泛、适用性强的成套焊轨工艺。
[Abstract]:Heavy haul railway undertakes the important task of transporting bulk goods and coal and so on. With the increase of freight volume, the rail bearing capacity is more and more high, the strength is high, the wear resistance of rail is good, and the application prospect of rail is broad. In order to obtain the high quality welding joint and ensure the safety and long life of the line to the maximum extent, it depends on the rail welding method, process selection and equipment control level. Therefore, using YHGQ-1200 pneumatic welding rail car, which has completely independent intellectual property rights in our country, to carry out systematic research on pressure welding technology of heavy-haul railway rail is of inestimable practical value to improve the welding level of heavy-haul railway. In this paper, GPW-1200 (75) pneumatic welding machine is used for the first time to study the welding process of 75kg/m U78CrV rail. The welding quality of 60kg/m U78CrV and U75V rail was studied by using YHGQ-1200 pneumatic rail car and the same welding rail process. At the same time, the welding technology of new type PG5 and bainite rail is discussed, which provides reference data for the application of heavy load line on PG5 and bainite rail in the future. The results show that: (1) the mixed welding test of 75kg / mU78CrV hot rolled rail is successful, and the joint impact energy is 15.8J, the tensile strength is 1005MPa, the elongation after break is 9.0. the hardness of the rail top is in the range of [1.061.09], the hardness of the joint is equal to the hardness of the base metal. The quality of joints with grain size above grade 7 fully meets the requirements of the standard TB / T1632-2014 rail welding for joint quality. (2) 60kg/m U78CrV and U75V rail air pressure welding shows that the weight, static bending and fatigue properties of 60kg/m U78CrV rail welded joints are stable. However, if the normalizing after welding does not adopt the forced air cooling process, the joint hardness is low and the quality of the U75V rail joint does not meet the standard of TB- / T1632. The hardness of the top surface of the joint rail is greater than 1.0, which is equivalent to the hardness of the base metal. It is shown that the saddle wear disease of heavy duty line welded joint can be reduced from the source. The gas pressure welding process is a complete set of welding technology, which can not only weld 60kg / mU78CrV (hot rolled and heat treated) rail, but also weld 60kg/m U75V rail.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U213.92

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