THE RESULTS OF ADJUSTING THE EQUIPMENT AND APPLYING THE DEFORMATION- HEAT TREATMENT TECHNOLOGY TO ROLLED METAL AT THE NEW ROLLING MILL 350

摘要

We present the results of adjusting the equipment and applying the deformation-heat treatment (DHT) technology to rolled metal at the new rolling mm 350 of Joint Stock Company OEMK equipped with 3 devices of rolled stock accelerated cooling: two afterdeformation devices in the fine-range and medium-range lines, and an interdeformation device in the fine-range line. The variation interval of the rolled metal temperature is set to be 750-990 deg C at the entrance of the finishing stands group, 820-1020 deg C at the exit of the last finishing stand, and 650-1020 deg C at reeling. The complex of mechanical properties of rolled low-carbon steel after the DHT is significantly improved. It is established that the toughness and plasticity properties enhance as the deformation temperature lowers mainly in the finishing passages due to the interdeformation cooling. The DHT and tempering of low-carbon manganese-boron steel performed at 680 deg C and at aging of 6.5 hours made it possible to obtain fine-grained pearlite and achieve hardness values of 145 HB.