Do You Know The Railroad Thermite Welding of Grooved Rail

Modern trams have advantages of energy saving, environmental protection, low investment, short construction period and good landscape effect, which is a new direction for the development of urban rail transit. The track is laid by the grooved rail to reduce vibration and noise during vehicle operation and increase passenger comfort.

The grooved rail is a specialized steel rail for urban railway, which is the most difficult to roll among all types of steel rail. Compared with ordinary steel rail, the grooved rail has an asymmetrical groove on the rail head, which has a complicated shape and is difficult to roll. It has the reputation of “king of the rail”. How to do the thermite welding of grooved rail? Let’s see the specific step of grooved rail thermite welding with AGICO Rail.

More about railroad thermite welding

Railroad thermite welding, also known as exothermic welding, is a rail welding technology formed by the principle of chemical reaction of aluminum and iron oxide to replace iron. Actually, the railroad thermite welding is a common technology that is widely applied in the modern railway track. How much do you know about railroad thermite welding?

Principal of railroad​ thermite welding

The Al welding agent is first placed in a high temperature resistant crucible, and then the ignited and high-temperature match is inserted into the Al welding agent, and the Al welding agent begins the aluminothermic reaction. During the reaction, iron oxide is reduced at high temperature to form molten iron and melts other added elements to form molten steel of a specific chemical composition, and the aluminum is oxidized and forms slag together with other oxides. The molten steel sinks to the bottom of the crucible due to the large specific gravity, and the slag has a small specific gravity and floats on the upper part of the molten steel. After the reaction is completed, and a short sedation, the slag floats up and is completely layered with the molten steel. The specially designed self-melting plug at the bottom of the crucible is automatically melted, and the high-temperature molten steel is released into the high-temperature sand mold connecting the two rails, thereby welding them together. The high-temperature sand type has the geometrical features of the rails, so that the welded joint is basically same as the rail. After the weld is cooled down, the mechanical properties can be further improved if appropriate heat treatment is applied.

• Preparatory work
• The treatment of rail end

• Rail adjusting

• Fixture installation
• Sand mould installation
• Sealing

• Pre-heating

• Crucible installation

• Ignition

• Reaction

• Form stripping

• Overlap removal

• Polish

• Finished product

The railroad thermite welding of AGICO

AGICO Rail is a trusted railway material supplier with rich project and advanced technology support. We can supply steel rail, rail fasteners and other railway products related to the railway construction. Railroad thermite welding is one of product of AGICO, we are specialize in thermite welding for common steel rail or grooved rail, and etc. What can we offer? The advantages of railroad thermite welding of AGICO Rail as following: 

• Economical: less material consumption and low cost;
• Practicality: less time and high efficiency;
• Conveniences: The auxiliary machine is light and small, also has low labor intensity;
• Versatility: Most of the operation process is similar to ordinary railroad thermite welding;
• Automatic pouring and optimum steel purity to ensure the quality of the welding head;
• Welding between the profiled rails is possible. (Example: grooved rails and common steel rails)
• Green and environment-friendly: do not harm the human body and do not pollute the environment.