PRODUCTION OF SEAMLESS HOT-ROLLED PIPES SIZED TO 630×28-32×4800-5500 mm FROM '15Х1М1Ф' AND '10Х9МФБ-Ш'-GRADE STEELS AT PRU 8-16' WITH PILGER MILLS FOR PIPELINES OF BOILER UNIT STEAM INTERMEDIATE OVERHEATING WITH HIGHER MECHANICAL PROPERTIES

摘要

FIELD: process engineering.;SUBSTANCE: invention relates to metallurgy, particularly, to pipe production. 630×28-32 mm pipes are produced from hollow ESR ingots-billets sized to 720×ID600×3200±50 mm. Said ingots-billets are heated to 1270-1290 and 1190-1210°C, respectively. Sleeves are roller and PRU 8-16" with Pilger mills to commercial pipes sized to 630×28-32×4800-5500 mm at rolls with body diameter of 1150 mm and groove of 640 mm. Rolling-out makes 1.9-2.13, diameter reduction makes 11.4%, sleeves m=16-18 mm being fed to straining source at rolling of 630x28 mm pipes. At rolling of 620x32 mm pipes at feed of sleeves m=18-20, process wastes are cut off by hot cutting saw, straightened at six-roll straightener, heat treated, etched, clarified, repaired if required, subjected to ultrasound inspection and accepted with diameter allowance of +1.25/-1.0% wall depth allowance of +20/-5.0%.;EFFECT: lower metal input, increased pipe length.;5 cl, 2 tbl