Application of Aluminothermic Welding of Rails on Crane Rails

Exothermic welding was founded at the end of the 19th century when H. Goldschmidt discovered aluminum powder and metal oxides can be caused by an external heat source to start an exothermic reaction, and once the reaction can continue by itself, the general formula of this reaction is:

metal oxide + aluminum (powder) → alumina + metal + thermal energy

Exothermic welding can mainly weld such as pure copper, brass, bronze, red copper, copper-clad steel, pure iron, stainless steel, wrought iron, galvanized steel, cast iron, etc.

Today, let's discuss the application of aluminothermic welding on crane rails.

Usefully, The crane is a double-girder structure, the crane rails run on the tracks of the main girder bridge. The rails of the main beams designed in China are generally mechanically in segmented and gaped connection, In the other words, they are ground or processed at the interface according to the length of the supply, they are formed by close joints.

The rail welding method, until now, there are mainly adopted gas pressure welding, contact resistance welding, manual arc welding, and aluminothermic welding. 

A few days ago, one of my customers from Malaysia ask us to support technology to upgrade the arc welding machine. Actually, arc welding quality is unstable, the serious defect such as slag and porosity can directly cause a break of welded rail. That’s why the Chinese market directly eliminates the welding method of arc welding.

Aluminothermic welding is applied to mine cranes and gantry tracks in various factories. The crane rails such as QU70, QU80, QU100, QU120, A100, A120, CR73, etc.

This aluminothermic welding process is characterized by simple equipment, convenient operation, high efficiency, good adaptability to working conditions, and stable quality. The fact that the welded railhead does not need to be treated, and the quality control of the entire welding process is performed by the fixed parameters of preheating time, oxygen flow, and liquefied gas pressure, which is easy for operators, will not be affected by other factors. The whole welding process of a single railhead is around 1 hour, which saves time and labor compared with other welding methods.