| 摘要 |
FIELD: manufacture of seamless tubes by helical and pilger rolling. SUBSTANCE: method comprises steps of plastic deformation of blank heated up to rolling temperature in piercing press in order to receive hollow blank; reducing walls of hollow tubular blank by thickness in mill for helical rolling with the aid of inner tool; subjecting tubular blank to elongation and then subjecting elongated hollow blank without bottom to plastic deformation in pilger mill in order to make tube by hot pilger rolling; subjecting blank without bottom to deformation at guiding it into mill for helical rolling by its end where bottom previously was (at looking in rolling direction); rotating hollow blank by 180 degrees before guiding it to pilger mill. EFFECT: elimination of inner defects of tubes such as bent up and expanded end portion. 4 cl, 2 dwg
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