| 摘要 |
PURPOSE:To efficiently produce high-chromium steel by providing fine-pipe perforated tuyeres of high-pressure pipings to the bottom of a furnace bottom to increase the flow rate of the bottom blowing gas in decarburization refining. CONSTITUTION:A metallic bath 2 is contained in the furnace body 1. Chromium ore, chromium oxide, carboneous material and fluxing agent are introduced into the furnace body through a throat 3. Oxygen is top-blown from a top blowing lance 4 to form slag 5 on the bath 2. The fine pipe perforated tuyeres 6, 6' are provided to the furnace bottom to blow a non-oxidative gas into the furnace. The tuyeres 6, 6' are constituted of the high-pressure pipings of >=10kg/cm<2> pressure. The max. blow rate of the gas to be blown through the tuyeres 6, 6' in the end period of decarburization refining is so adjusted as to be >=3 times the min. flow rate of the gas to be blown in the melt reduction period. The intrusion of the slag in the reduced chromium is prevented by the above-mentioned, by which method the economical production of the high- chromium steel with a short period of the decarburization treatment is made possible. |
