Understanding the Heat Treatment Involved in the Process of Manufacturing TMT Bars - Maan Shakti (2024)

Someone involved in the construction industry, be it an engineer, contractor, or architect, may already know the role of TMT bars in construction. But do you know why these bars are so popular in today’s construction? Well, unlike manufacturing steel bars, TMT bars undergo a special treatment called thermo-mechanical treatment. In this special method, the bars go through a set of treatments that make them ductile, strong, and corrosion-resistant.

So, are you planning to buy TMT bars in bulk from the best TMT bar manufacturers? Wait before you make a choice. This post describes the thermo-mchanical treatment of TMT bars in detail.

An Overview of TMT Bars – What Are They and How Are They Beneficial?

Also referred to as thermo-mechanically treated bars, they are used in construction projects like buildings, flyovers, bridges, and other constructional structures that bear massive loads. Due to their thermo-mechanical treatment, these bars are strong and ductile.

Compared to the conventional methods of manufacturing steel bars, heat treatment acts as a game changer. It is a metallurgical process that combines mechanical deformation methods like forging or compression, rolling, quenching, heating, cooling and more.

These processes build the strength and ductility of these bars with a hard outer layering and a soft inner core. The following are the steps involved in the thermo-mechanical procedure:

Step 1 – Passing into the Furnace

In the beginning, the billets are passed into the furnace with the help of the rolling mill stand. After this, steel billets are heated between 1200°C and 1250°C in the reheat furnace. Next, they are rolled to reduce billets and form the final shape and size.

Step 2 – Quenching and More

In the second step, the rolled steel is then passed through the cooling system, also referred to as quenching. When this process happens, the water pressure gets optimised accordingly. Quenching turns the surface layer of the billet to martensile, thereby making it shrink. This process helps form the right crystal structure. At this point, the core is still hot and austenitic.

The water flow is controlled by a processor that helps manage the temperature differences via the bars’ cross-section. Quenching converts the bar and makes it stronger. In addition, it also tempers the quenched layers with the help of the heat acquired from the core. The drastic temperature change makes the outer layer firm and durable.

Step 3 – The Ultimate Cooling

Now coming to the final step! As soon as the process is complete, TMT bars undergo atmospheric cooling. It equalises the temperature difference between the hard outer layering and the soft inner core. Soon after the TMT bar cools down, it attains austenitic and martensite conditions. As a result, the inner core is soft and gives the bars great tensile strength. The prime USP of TMT bars lie in this design, which offers excellent ductility. This is the reason why TMT bars are corrosion-resistant.

Top Benefits of the Thermo-Mechanical Treatment in TMT Bars

Thermo-mechanical treatment is the reason why the TMT bars are strong. In fact, TMT bars have become a crucial material in the construction industry due to their specific thermo-mechanical treatment. You can learn further about the benefits from the following points.

Ensures Ductility

Now, what makes TMT bars ductile, and how is it beneficial for the construction industry? Well, ductility is the bar’s ability to deform before fracturing. In the mechanical treatment, the process improves the bars’ ductility. This ensures that they do not become brittle. In addition, it also ensures that the bars absorb more energy before failing. Such a trait is beneficial for construction projects occurring in seismic regions where the occurrence of earthquakes is common.

Improved Strength

Did you know the mechanical treatment of bars can improve the yield strength? This is the reason why the ultimate tensile strength is achieved. That means the structures built with the bars can bear high loads without sacrificing the safety of the people and surroundings.

Makes the Bars Corrosion-Resistant

Corrosion was a common issue in most construction structures previously. However, after the advent of TMT bars in the Indian construction industry, this issue has been reduced. Considering these bars, the microstructural changes because of the heat treatment may improve corrosion resistance.

Note that corrosion occurs when the metal slowly deteriorates due to moisture and other environmental aspects. For construction projects, corrosion or rust is usually common in coastal regions. However with the use of TMT bars, this issue can be mitigated effectively – thanks to the unique structure of these bars. Notably, TMT bars have a hard layer and soft inner core that prevents corrosion.

A Greater Bond Strength is Achieved

The thermo-mechanical treatment may also improve the bond strength between TMT bars and their surrounding concrete. Better grip and improved surface deformation make these bars achieve a greater bond strength.

Considering the benefits of TMT bars, the construction world is gradually implementing their use in infrastructure, industrial construction, and even real estate. Even small-scale regional manufacturers have been using these bars to improve their construction procedures.

However, if you plan to buy TMT bars for your next construction project, you must consider their certifications. Look for bars manufactured with BIS and ISI certifications that ensure quality. The demand for durable, safe, and strong construction materials is high. With that, heat-treated TMT bars have become a quintessential material in India’s construction and infrastructure sectors. The future holds better days for construction as manufacturers have started investing in upgrading their facilities and improving their mechanical treatment processes.

Finally

So, whether you are a contractor or engineer, you can rest assured that the thermo-mechanically treated bars are here to stay. So, get in touch with a reliable and leading TMT Bar producer to buy these bars in bulk.