TMT (Thermo-Mechanical-Treatment) is a special heat
treatment process, wherein the heat treatment is right from
rolling process.
At the exit of the rolled product, the ribbed bar is
subjected to the TMT process across 3 stages.
Stage 1: This
involves successive steps of rapid quenching in a special water
system converting the surface layer of ribbed bar into a
hardened structure.
Stage 2: This is tempering process, which
involves the flow of the heat from the core of the bar to the
surface.
Stage 3:
Finally, the bars are cooled in atmospheric air on the cooling
bed. This transforms the outer case of the bar into tempered
martenstic state, while internally the bar becomes a fine
pearlier core. The
TMT process eliminates all undesirable qualities of the
normally treated bar.
The TMT, therefore attains higher strength, and this gives
the bar excellent ductility, enhanced bend ability and
superiority.
Merits of TMT
• Saves 14% - 19% steel
• Better safety of structures,
owing to higher elongation
• Suitable
seismic
loading (i.e.,
in earth-quake prone areas) due to enhanced fatigue
resistance
• Suitable for area prone to fire hazards
•
Improved resistance to corrosion than
CTD bars
• Pre-fabrication of meshed possible
•
Ease in working on-site
