| 摘要 |
FIELD: rolled tube production, namely processes for piercing ingots and billets for making seamless hot-deformed large-diameter tubes. ^ SUBSTANCE: method comprises steps of heating ingots and billets until yielding temperature; piercing them to hollow thick-wall sleeves in first skew rolling mill for further expanding to thin-wall sleeves in second skew rolling mill and rolling to large-diameter tubes in plants provided with automatic or pilger mills; piercing ingots and billets to thick-wall sleeves in first piercing mill with working rolls driven to rotation in one side and expanding billets to thin-wall sleeves in second piercing mill with working rolls driven to rotation in opposite side. ^ EFFECT: enhanced geometry of tubes, lowered metal consumption, improved efficiency of tube rolling plants. ^ 1 tbl |
