| 摘要 |
PURPOSE:To eliminate the possibility of pollution and cast lead free cutting steel in good yields by adding lead (alloy) in the form of a wire rod coated with other pollution free metallic material directly into the molten steel in a mold. CONSTITUTION:Molten steel M is charged through a nozzle 2 into a tundish 3, thence it is charged through a charging port 4 into a mold 5, whereby it is cast continuously. At this time, a wire rod consisting of lead (alloy) coated with other pollution-free metallic material such as Al, iron or the like is supplied continuously through a guide pipe 8 into the molten steel in the upper part of the mold 5, whereby it is melted and added. According to this method, the lead is melted in the relatively narrow upper part in the mold 5 and therefore it can be melted uniformly into the molten steel. The evaporation of the lead prior to addition is obviated, the yield of the addition is improved and the occurrence of pollution is prevented. |
