PROCESS OF THERMAL TREATMENT OF WELD AND ZONE OF HEAT EFFECT OF STRAIGHT-WELDED PIPES Russian patent published in 2004 - IPC

FIELD: pipe rolling, hardening of electric welds and zone of heat effect of straight-welded pipes subjected to thermal treatment in production line. SUBSTANCE: in compliance with invention cooling sprayer comes in the form of eight collectors placed in parallel one another and with interval of 40-50 mm. Collector first from inductor carries one row of five nozzles which are positioned at angle of 45 degrees with vertical axis of collector to prevent water from hitting inductor and to raise magnetic field in heating zone of weld and zone of heat effect, they are directed along pipe. Collectors from second to seventh carry three rows of nozzles, each row includes five nozzles. First row of nozzles is positioned in parallel with vertical axis of collector, perpendicular to weld in pipe, second row of nozzles is placed at angle of 25 degrees and third row at angle of 45 degrees with vertical axis of collector and are heated along pipe. Eighth collector carries two rows of nozzles, first row being arranged in parallel to axis of collector, second row being arranged at angle of 25 degrees with vertical axis of collector. Central nozzle of each row of collector is slit- shaped, forms right angle between axis of nozzle and axis of collector and creates right-angled jet of cooler that is directed on to weld of pipe. Middle and extreme nozzles have round shape and are placed along collector with interval of 40-50 mm; they form jets of cooler of conical shape. Axes of middle and extreme nozzles are oriented in opposition and are placed correspondingly at angles of 30 and 60 degrees with axis of central nozzle. Jets of middle nozzles are directed on to weld and zone of heat effect and jets of extreme nozzles are directed on to center of weld, zone of heat effect and zone close to weld. EFFECT: equalization of mechanical properties of wells and zone of heat effect to level of basic metal or to values exceeding those of basic metal, enhanced efficiency of inductor. 1 cl, 3 dwg, 1 tbl