高速铁路钢轨焊接技术的发展与应用

Development and application of rail welding technology for high-speed railway

主要介绍高速铁路钢轨及钢轨焊接技术的国内外发展和应用现状。采用合金化和热处理方法提高珠光体钢轨的力学性能已接近极限,而贝氏体钢轨不仅具有优异的力学性能,而且具有优良的耐磨和耐表面伤损性能,是21世纪的钢轨发展方向。无缝线路的钢轨焊接主要有闪光焊、气压焊、铝热焊和电弧焊4种方法。闪光焊主要用于厂焊或基地焊;移动闪光焊和移动气压焊用于单元轨节现场焊;铝热焊和电弧焊常用于现场锁定焊、大修换轨和道岔焊接。闪光焊的焊接接头质量和生产效率是最佳的,相对于闪光焊,气压焊在单元轨节焊接中成本优势明显。铝热焊和电弧焊属于钢轨原位焊接,铝热焊操作简单灵活,但焊接接头综合性能较差;电弧焊在日本应用广泛,中国正在开展全自动钢轨窄间隙电弧焊接设备的研究开发和应用试验。

The development and application of steel rail and its welding technology used in high-speed railway at home and abroad was introduced in this paper.It has approached the topmost level by alloying and heat treatment to improve the mechanical properties of pearlitic steel rail.So that,bainite steel rail is the development tendency in the 21th century,for it not only has excellent mechanical properties,but also has better wear resistance and surface failure properties.There are 4 main methods,that are flash-butt welding,gas-pressure welding,aluminothermic welding and arc welding,which being applied for the welding of continuous welded rail.Flash-butt welding is mainly used in factory or base welding;Moving flash-butt welding and gas-pressure welding are used in construction site welding of rail link;aluminothermic welding and arc welding are usually used in site locking welding,rail replacement of heavy repairing and railway switch welding.The joint quantity and productivity of flash-butt welding are optimal,but gas-pressure welding has obvious advantage in cost with respect to flash-butt welding in the welding of rail link.Aluminothermic welding and arc welding are both in-situ welding methods.Though aluminothermic welding has the benefits of simple operation and flexibility,its welding joint has poor comprehensive mechanical performance.Arc welding has been widely used in Japan,and the automatic narrow gap arc welding equipment has been developing and carrying through verification test in our country now.