Metallurgical processes

In a method for the manufacture of a member selected from the class consisting of very low carbon steels, alloy steels and ferrous alloys, having low phosphorous, sulphur and nitrogen contents, in a steel converter or electric furnace which includes generating heat and a controlled atmosphere by means of an oxy-fuel or air-fuel burner, in which fuel consumption is reduced and efficiency is improved, the improvement which comprises use of a fuel which has a heat of decomposition ranging from exothermic to an endothermic heat of decomposition of not more than 1.0 K cals per carbon atom of said fuel expressed as a hypothetical hydrocarbon C.sub.1 H.sub.x, said fuel being selected from the group consisting substantially of hydrocarbons and mixtures of hydrocarbons having 1 or more double bonds, including those having a ring structure or fused ring structure, hydrogen and carbon and in which a steel melt is subjected to a number of alternate short periods of, respectively, high and low oxygen potential, in the first of said periods the carbon and other impurities being oxidised and removed from the system, mainly as carbon monoxide, while simultaneously part of the metal in the melt forms its oxide and is absorbed in the slag;

• and in the second of said periods the carbon continues to be purged from the melt by the blowgas as carbon monoxide, while the metallic oxide is reduced to metal again, the said low oxygen potential periods being achieved by lowering the H ratio of the blowgas without metal oxide addition.