| 摘要 |
1290774 Producing leaded steels NIPPON KOKAN K K 22 Sept 1970 [4 Oct 1969] 45025/70 Heading C7D Free-cutting lead steels are produced by adding lead or lead alloy in rod form to molten steel in a ladle the steel being stirred by passing therethrough a gaseous substance such as argon or nitrogen, the rod of diameter 5-20 mm., being fed into the steel at a velocity of 1-20 m. /sec. the gas may be blown into the melt through a porous brick in the base of the ladle or through a long porous tube extending downwards into the melt. The lead may contain aluminium, silicone, manganese, chromium or nickel. Specification 1, 219, 706 is referred to. |
