Aluminothermal rail welding process. Rio de Janeiro subway (2)

This welding process, also known as welding a group of processes that uses heat released by a exothermic reaction to enable welding.

The exotherm of the reduction of a metal oxide is used as a source of energy for welding.

The oxides used are those that have a low heat of formation, while the reducing agents are those that have high heat formation.

The ends of the components to be soldered are placed

Inside a mold, specially constructed for the parts to be

welded.

In the case of welding cables or electrical connections, a Carbon-bonded graphite crucible; In the crucible that interconnects with the mold is placed the metal oxide (which will be reduced to pure element) and aluminum which is the reducing agent.

Steel produced in a refractory crucible, the

temperatures above 2000 ° C, is carried to the tops of

Rails, dissolving them and joining them homogeneously.

After 4 to 5 minutes the formers are removed and the surplus material is deburred. after the the weld is ground to reproduce the rail profile.

Done