METHOD OF MAKING WELL CASING SIZED TO 244,5×7,9, 244,5×9 AND 244,5×10 mm AT PIPE ROLLING UNIT WITH PILGER MILLS

摘要

FIELD: process engineering.SUBSTANCE: invention relates to pipe rolling. Continuously-cast 430 mm-dia billets are heated to plasticity temperature. Said billets are pierced at piercing mill on 250 mm-dia mandrel with drawing µ=1.56. Produced sleeves are rolled at Pilger mill to pipe sections at fixed sleeves feed to strain zone at steady-state rolling conditions m. Pipe sections are cut to equal lengths, heated, gaged and straightened. Preliminary acceptance is carried our, thread is cut, couplings are screwed on, hydraulic tests are carried out and pipes are accepted. Continuously-cast biller length is defined by relationshipswhere L=36000 is design length of rolled pipe, mm; µ=µµis total factor of drawing the billet to commercial; Ris billet radius, mm; K=0.965 is factor allowing for waste of metal at heating in continuous furnace; D=244.5 is rated pipe OD, mm; Sis design wall depth at pipe rolling at Pilger mills equal to 8.25, 9.25 and 10.35 mm.EFFECT: higher reliability of screwed pipe joints.3 cl, 1 tbl