AT PMC, all processes are integrated to create a streamlined flow of process - from delivery of raw material delivery to dispatch of the finish Thermex TMT Steel Bars. The unique plant layout and best quality equipments offer uncompromising levels of quality, accuracy and productivity to PMC’s customers. The TMT Steel Bar manufacturing process begins with selecting the raw materials and continues with the 2-strand Continuous Caster that produces high quality steel billets as input materials. These are then put through the reheating furnace and made ready for the final stage of production.
Produced under strict quality control, PMC PRESTIGE Thermex TMT Bars thermo-mechanically impart work hardening and heat-treatment of steel into a single process. These are centrally controlled through a processing unit that integrates end-to-end production, executed by a highly skilled team. The quenching process produces a high strength bar from inexpensive low carbon steel. It quenches the surface layer of the bar, which pressurises and deforms the crystal structure of intermediate layers, and simultaneously begins to temper the quenched layers using the heat from the bar’s core. Steel billets 125mm² are heated to approximately 1100°C in a reheating furnace. They are progressively rolled to convert the billets to the final size and shape of reinforcing bars.
After the last rolling stand, the product moves through a quench pipe which converts the bar’s surface layer to martensite and causes it to shrink. The shrinkage pressurises the core, helping to form the requisite micro-structure. The core remains hot and austenitic. A microprocessor controls the water flow to the quench pipe to manage the temperature difference through the cross-section of the bars. The correct temperature difference assures the process requirements for bars to have the necessary mechanical properties. As the bar cools, heat flows from the bar’s centre to its surface so that the heat and pressure correctly temper to form an intermediate ring of martensite and bainite.
Finally, the slow cooling after quenching automatically tempers the austenitic core to ferrite and pearlite on the cooling bed. These bars, therefore, exhibit a variation in microstructure, having strong tempered martensite in the surface layer of the bar, an intermediate layer of martensite and bainite, and a refined, tough and ductile ferrite and pearlite core. PMC’s quality department applies a strict procedure of inspection along the entire process cycle, starting with detailed inspection of raw material to final inspection of finished products and strict supervision of the process all through out.