WHAT IS TMT REBAR (STEEL BAR)?

It is the popular acronym for THERMO-MECHANICAL-TREATMENT

TMT processes?

Thermomechanical processing, also known as thermo-mechanical treated bars’ (TMT), is a metallurgical process that integrates forging, rolling and/or work hardening with heat-treatment into a single process.

TMT is rolled from high quality low carbon (below 0.24%) billets. BOF refined liquid steel is routed through a PLC controlled LRF before being cast into billets on a continuous caster.

This is a special heat-treatment process, wherein the heat treatment is from the rolling process itself.

At the exit of the rolled product, the ribbed bar is subjected to the TMT process, which involves three (3) processes

Process 1: Successive steps of rapid quenching in a special water system converting the surface layer of ribbed bar into hardened structure.

Process 2: The tempering process involving the flow of heat from the core of the bar to the surface

Process 3: Finally, the cooling the bars in atmospheric air on the cooling bed. This transforms the outer case of the bar into tempered martensitic state, while internally the bar will be a fine ferrite pearlite core. The TMT process eliminates all undesirable qualities of the normally treated bar.

The TMT re-bar, therefore, attains higher strength and achieves excellent ductility, enhanced bendability and superior weldability.


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