In the Gamharia plant, different categories of wire rods are rolled which include Plain Carbon/High Carbon/Low carbon/Low carbon CHQ/Free cutting /Ball bearing/Roller Bearing/Boron steel/Spring Steel/Alloy steel, Leaded steel, Electrode quality and MS grades.
The wire rod refers to the hot-rolled round steel with a diameter of 5.5-25.4 mm. As the final product is delivered in coil form, it is also commonly known as the coil. The wire rod outputs in Gamharia are of two size ranges, e.g. 5.5-18.5 mm through block route and 20-25.4 mm through garret route.
Conditioning of Billets: Wire rod billets are mainly made of continuous casting billet, and their cross-section is generally 150X150 mm2. The process followed to inspect the quality of continuously cast billet surface is through visual inspection after removing the scales through shot blasting process. Billet corner grinding as well as the surface grinding facility is available and used for all critical applications before rolling.
Heating: It is generally heated by a walking beam furnace. The walking beam furnace is used to efficiently heat the input material to rolling temperatures with satisfactory temperature uniformity throughout the length and breadth of the as-cast billet for further processing. As per the typical process requirement, it is to be ensured that the decarburization level is small, the billet is not twisted, and no overheating is caused.
Rolling: The temperature, draft and speed of deformation are the key parameters with which the product is rolled and controlled to meet customer requirements. Further measures to ensure the surface quality include the adjustment of roll roughness and gap, detection of any cracks and dimensional correction.
Post rolling treatment/Stelmor cooling: To attain desired microstructure and mechanical properties after rolling, the rolled product is placed on a conveyor through laying head pipe for Stelmor cooling.