Abstract: In a method for producing seamless pipes, a hot hollow block created previously in a piercing mill is stretched by means of a continuous rolling mill on a mandrel bar to form a parent pipe and the parent pipe is fed directly to a stretch reducing mill or sizing mill as a finishing mill, while forgoing an extracting mill and a reheating furnace, and is rolled there to the required final pipe diameter. The hollow block is pre-dimensioned in its length in such a manner that only a single length is produced as the required parent pipe length during the stretching in the continuous rolling mill and the parent pipe is pulled off of the mandrel rod by the finishing rolling during the subsequent finishing rolling, wherein the rolling is performed using rolling mill components that are designed in the dimensions thereof for handling single lengths.

Abstract: In a method for producing seamless pipes, a hot hollow block created previously in a piercing mill is stretched by means of a continuous rolling mill on a mandrel bar to form a parent pipe and the parent pipe is fed directly to a stretch reducing mill or sizing mill as a finishing mill, while forgoing an extracting mill and a reheating furnace, and is rolled there to the required final pipe diameter. The hollow block is pre-dimensioned in its length in such a manner that only a single length is produced as the required parent pipe length during the stretching in the continuous rolling mill and the parent pipe is pulled off of the mandrel rod by the finishing rolling during the subsequent finishing rolling, wherein the rolling is performed using rolling mill components that are designed in the dimensions thereof for handling single lengths.

Abstract: The invention relates to a forging mandrel for hot-forging tubular workpieces of metal, said mandrel comprising a mandrel body and a mandrel bar, in which forging mandrel the mandrel body is composed of a heat-resistant material. The forging mandrel according to the invention is embodied here in such a way that the mandrel body is provided, at least in the work zone, with a layer which reduces the dissipation of heat into the mandrel body during the forging process and adheres firmly to the mandrel body, wherein the layer has a lower thermal conductivity than the material of the mandrel body and has a thickness of at least 50 ?m.

Abstract: A method of manufacturing high-strength seamless steel tubes by hot-rolling followed by accelerated cooling in which feed ingots of a steel annealed with aluminum and/or silicon of the following composition in weight per cent:______________________________________ 0.08-0.13% C 1.40-1.90% Mn 0.20-0.50% Cr 0-0.50% Mo 0-0.70% Ni 0-0.40% Cu 0.04-0.13% V max. 0.020% P max. 0.010% S ______________________________________and wherein the balance comprises iron and ordinary impurities, the sum of the contents of Cr and Mo is within the range of about 0.20 to about 0.70% and the Cu/Ni quantity ratio in case of the presence of both elements is limited to at most 1, are heated to a temperature of about 1150.degree. to about 1280.degree. C. and hot-rolled into tubes in multiple stages and, after leaving the last hot-rolling stage, the tubes which have a temperature above A.sub.