1. Rolling: The 4-high reversible finishing mill with the maximum load of 7000 tons minimizes internal defects even inly thick plates. Automatic gauge control and shape control systems can reduce not only the thickness deviation of plates but also improve the flatness.
2. Cooling: The cooling system enables the production of high strength steel without heat treatment through rolling and accelerated cooling. Using the mist cooling method with suction type, the system has a high cooling capacity and is able to maintain a uniform temperature gradient in the widthwise direction. This leads to a reduction of plate quality deviation.
3. Hot Leveling: The hot leveler is used to make superior quality flat plates by eliminating residual stress left on rolled plates.
4. Slitting: After passing through the cooler, the plates undergo a dimensional accuracy inspection and then cut into appropriate width and length according to plate grade and thickness using either mechanical shearing machine or flame planner. To obtain a higher degree of dimensional accuracy in products, production conditions are determined by such factors as the air knife gap and the nozzle size of the gas torch.
5. Heat Treatment: To attain the plate structure demanded by customers, plates undergo heat treatment after having the scale removed by shot blasters. The heat treating facilities are of a non-oxidizing radiation tube type, which produces scale-free heat-treated plates.
6. Ultrasonic Tester Checks: The ultrasonic tester checks for blow holes, pipes, and laminations and other internal defects. This test is performed to guarantee the internal quality of plates demanded by customers.