| 摘要 |
FIELD: tube rolling. ^ SUBSTANCE: proposed method includes making of ingots with subsequent turning and drilling of central hole, heating of ingots to plasticity temperature, piercing in skew rolling mills into shells with fit to diameter of 8-16% and rolling on pilger mills with tolerance to wall of +20/-15%. Thickness of cut metal layer at turning of ingots is increased with increased in diameter whose value is found from expression ▵S=0.0125*D where D is diameter of ingot, mm. Diameter of central drilling of ESR ingots is found from expression ddr=do+▵(Dc-Do) where do=100 mm is value of central drilling of ingots, diameter 500 mm; ▵=0.075 is coefficient taking into account outer diameter of ingots; Dc is current of outer diameter of ingots; Do - is ingot, diameter 500 mm. Reduction of ingots at piercing is decreased with increase in diameter and is found from expression epsilont=epsilono-epsilont(dc-do) where epsilono is reduction of ingots, diameter 400 mm, equal to 16%; epsilont is coefficient = 0.003%/mm; dt is current diameter of ingots, mm; do is diameter of ingot, 400 mm. Rolling of tubes on pilger mill is carried out with tolerance in thickness of wall equal to +15/ - 10%. ^ EFFECT: reduced power consumption at piercing, reduced consumption of metal at making of boiler tube from ESR ingot, improved mechanical properties of tube metal. ^ 4 cl, 2 tbl |
