| 摘要 |
FIELD: rolled tube production, namely calibration of rolls of pilger mills for rolling thick-wall large- and mean-diameter tubes, possibly in tube rolling aggregates with pilger mills. ^ SUBSTANCE: roll has along circle of its barrel round cross section groove with outlets. Length of said groove is determined by successively arranged: striker formed by radius of growing ridge of roll, polishing portion with constant or smoothly decreasing radius of roll ridge, lengthwise outlet angle and idle portion. Cross section of groove along length of polishing portion smoothly decreases by value ▵ not exceeding half of admissible error of tube diameter. Said value ▵ = (0.10-0.65)D/S where S - thickness of tube wall, mm; D - diameter of tube, mm; 0.10 - coefficient for tubes with relation D/S=15.0 and 0.65 - for tubes with relation D/S = 4.0 or less. If relation D/S is in range 15 - 10 cross section of groove along length of polishing portion decreases by value ▵1 = 0.5 - 1.0 mm; at relation D/S in range 10.0 - 6.0 ▵2 = 1.0 - 1.5 mm; at relation D/S equal to 6.0 or less ▵3 = 1.5 - 2.0 mm. ^ EFFECT: possibility for making boiler and thick-wall tubes with more narrow allowances along wall, elimination of tubes rejected by trimming, lowered metal consumption factor at conversion blank - thick-wall tube, reduced cost of such conversion. ^ 2 cl, 1 tbl |
