Method for manufacturing seamless tubes by a bar rolling mill three cylinders

摘要

Method for manufacturing seamless tubes of metal, especially steel, in which a hot bloquehueco previously generated is stretched by a rolling bar three cilindrossobre bar mandrel to form a mother tube and the hollow block I is provided before entry into the Trende bar rolling on an upstream frame having a rolling step homogenizing the diameter, characterized in that the cylinders of the upstream stand are raised and lowered in the same way as losbastidores transformation rolling mill bars, so that the basic radius calibration loscilindros the upstream stand extends over 60 ° and this remains within the flanks transicióntangencial which is dimensioned such that even in the case of maximum adjustment cylinders lazona of the flanks is done almost no reduction of the expected maximum diameter of the hollow block.