Abstract: A method of melting an iron-containing cold material and simultaneously obtaining a low phosphorous and high carbon molten iron while maintaining a high post combustion rate, comprising the steps of: preparing a converter having a lance for top-blowing oxygen, and a bottom-blowing triple pipe nozzle disposed at a bottom of the converter which nozzle is provided with an inner pipe, an intermediate pipe and an outer pipe; supplying the iron-containing cold material into the converter in which a hot heel exists; introducing into the converter all of a carbonaceous material together with a non-oxidizing gas through the inner pipe of the triple pipe nozzle, oxygen through a space defined between the inner pipe and the intermediate pipe, and a non-oxidizing cooling gas through another space defined between the intermediate pipe and the outer pipe, and additional oxygen through the oxygen top-blowing lance so that the cold material is melted into a molten iron under an existence of slag; maintaining both the content

Abstract: In a press-rolling process for producing a metal tubular product, which comprises a pipe-forming procedure in which a square metal billet is fed into a rolling mill which consists of a pair of pressing rolls which have semi-circular grooves forming circular shape and which is provided with a plug held in the center line of the circular shape, according to the present invention, the press-rolling process is characterized in that a cavity is formed in the center portion of the forward surface of the billet before the pipe-forming procedure, the diameter of the cavity corresponding to 70% or more but less than 100% of the diameter of the plug and the volume of the cavity being equal to or more than the volume of a portion of the plug located in the inserting side of the billet from the axial center of the rolling mill.