Nucor Orders Two Heat-Treatment Lines for Kentucky Plate Mill
Nucor Corp. awarded SMS group a follow-up order for the supply of reheat and heat-treatment facilities for its plate mill being built in Brandenburg, Ky. Nucor previously ordered a slab-casting machine for the new mill from SMS group in 2019. The follow-up contract is for all of the plate mill’s slab and ingot reheat equipment, a heat-treatment line for heavy plate up to 14 inches (356 mm) thick and a continuous heat-treatment line for plate between 0.19 and 14 inches (4.8 and 102 mm) thick and up to 168 inches (4,267 mm) wide.
SMS group’s scope of supply includes a walking-beam furnace for the transfer of slabs from the casting machine to the rolling mill. The furnace will be designed for slab direct, hot and cold charging. Slabs a maximum length of 600 inches (15,240 mm) will be charged in a single row; shorter ones in two or three rows. The furnace will be fitted with SMS-ZeroFlame burners, which are characterized by extra-low NOx emissions. SMS group will also supply bogie-hearth furnaces that will be able to reheat ingots of various sizes.
The contract includes additional bogie-hearth furnaces and a quenching facility, which Nucor will be using for a wide range of heat treatments – from low-temperature annealing to normalizing.
SMS group will also supply a continuous heat-treatment line incorporating MultiFlex-Quench, which will be arranged downstream of the rolling-mill facilities. For hardening and normalizing, the plates will be heated in a high-temperature roller-hearth furnace. The furnace will feature two chambers of different temperature ranges. The plates will be heated by radiant tubes in a nitrogen-based inert atmosphere. A low-temperature furnace installed in the line will be used for plate tempering, and a specially designed gas-recirculation system will provide optimal convection within the furnace chamber.
Commissioning of the plant is scheduled for 2022.