Abstract: Refining method of molten metal which employs a refining apparatus provided with a tiltable refining vessel, a tuyere formed therein for blowing inert gas and/or flux or further sometimes additive alloy component(s), with the aid of inert gas into the molten metal, and a suitable number of electrodes for heating the molten metal and flux, for the purpose of performing a first refining process of carrying out the heating of the molten metal and the flux with the electrodes and a second refining process of tilting the vessel for blowing into the molten metal insert gas and others from the tuyere, whereby harmful or unnecessary metallic and/or non-metallic impure components can be removed for improving the quality of the article.

Abstract: Refining method of molten metal which employs a refining apparatus provided with a tiltable refining vessel, a tuyere formed therein for blowing inert gas and/or flux or further sometimes additive alloy component(s), with the aid of inert gas into the molten metal, and a suitable number of electrodes for heating the molten metal and flux, for the purpose of performing a first refining process of carrying out the heating of the molten metal and the flux with the electrodes and a second refining process of tilting the vessel for blowing into the molten metal inert gas and others from the tuyere, whereby harmful or unnecessary metallic and/or non-metallic impure components can be removed for improving the quality of the article.

Abstract: Low carbon calcium-sulfur containing free-cutting steel exhibiting improved machinability is disclosed. The said steel consists essentially of 0.03 to 0.10% carbon, up to 0.3% silicon, 0.8 to 1.5% manganese, 0.04 to 0.10% phosphorus, 0.20 to 0.45% sulfur, 0.0003 to 0.0050% calcium and the remainder being iron and inherent impurities such as copper, nickel, chromium and nitrogen; and is prepared by regulating the composition of the steel so that the value of theoretical Brinell hardness of the steel matrix, which is determined on the basis of the content of carbon, silicon, manganese, phosphorus, sulfur, copper, nickel, chromium and nitrogen in the steel, to a value between 110 and 130, and by forming and maintaining in the range of from 100 to 500 grams per steel-ton oxide inclusions of type JIS-A2 (ASTM-C) which soften or fuse at a temperature not higher than 1400.degree.C.