Development history of seamless steel rail in China

seamless steel rail

China’s seamless rail technology is independently developed. As early as 1957, China had already started researching this technology. At the beginning of this century, China’s railways carried out six major speed increases. At that time, China’s train speed had reached more than 140 kilometers per hour.

At this time, seamless steel rails have already begun to be used on a large scale. The characteristics of seamless steel rails with low noise and vibration and smooth driving were widely praised at that time. But the technology at that time was not enough for high-speed rail track with a speed of more than 300 kilometers per hour, and China soon upgraded the seamless rail technology.

The seamless steel rails laid on the high-speed rail in China are first welded into a 500-meter-long long rail by welding five 100-meter-long steel rails from the factory. During the welding operation, the maximum temperature of the welding head exceeds 1000 degrees Celsius. Operators’ overalls were often wet and wet. Then the operator uses the cutting machine tool independently developed by China to perform high-precision grinding on the welding points, and the precision must be controlled at the level of one-tenth of a millimeter.

After the welding is completed, the surface damage of the rails must be inspected. After more than ten processes such as rust removal, dehumidification, rough grinding, normalizing, precise calibration, and joint flaw detection, they are finally put into the transport vehicle after passing the inspection. This 500-meter-long long rail weighs 30 tons. It requires 36 gantry cranes to work synchronously, and it takes more than ten minutes to put it into a special transport vehicle. The transport vehicle is composed of 36 flatbed vehicles with a length of 12.5 meters.

It is then transported to the laying site and welded into longer rails. After soldering, each solder joint needs to undergo a hammer drop test. That is, a one-ton hammer falls freely from a height of 5.2 meters and hits the solder joints of the rails. This is also essential because the wheels of a high-speed train have a huge impact on the rails when they are in motion.

After the high-speed rail is put into official operation, the rails need to be polished and maintained regularly. At night when the high-speed rail is suspended, rail grinding vehicles are often dispatched. The grinding car travels on the railway at a slow speed of 3 to 24 kilometers per hour to perform grinding operations. To ensure the smoothness of railway rails.

In addition, China has also independently developed seamless line rail replacement equipment, which can recycle old iron fasteners while replacing rails. While replacing manual labor, it has effectively improved operating efficiency and quality and even made this work at night. It can also be carried out without affecting the operation of the high-speed rail daytime event.