MANUFACTURING METHOD OF SEAMLESS TUBES WITH DIMENSIONS OF 530×25-30 mm FOR STEAM BOILERS, STEAM LINES AND HEADERS OF PLANTS WITH HIGH AND SUPERCRITICAL STEAM PARAMETERS FROM INGOTS OF ELECTROSLAG REMELTING PROCESS FROM STEEL GRADE "10Х9МФБ-Ш" Russian patent published in 2015 - IPC B21B19/04 

FIELD: metallurgy.

SUBSTANCE: cakes of an electroslag remelting process (ESR) with the dimensions of 620×100×1750±50 mm are heated to the temperature of 1190-1210°C. Cakes are stitched in cross-helical rolling mills into shell workpieces with dimensions of 650×in315×1940-2050 mm on a mandrel with a diameter of 300 mm with drawing μ=1.14 and rise as to diameter of 4.7-4.9%, cooled and again heated from cold charging to the temperature of 1200-1220°C. The shell workpieces are stitched and rolled into shells with dimensions of 680×in490×2830-2980 mm on the mandrel with a diameter of 475 mm with drawing μ=1.43 and rise as to diameter of 4.5-4.7%. Rolling of shells is performed on a 8-16" TPU turning machine with pilger mills into semi-finished tubes with dimensions of 550×45×5000-5400 and 550×48×4600-5000 mm with drawings μ=2.45 and μ=2.31 respectively, by swaging as to diameter of 19.1%, with supply of shells to a deformation zone at rolling of tubes with dimensions of 550×45 mm m=15-16 mm, and at rolling of tubes with dimensions of 550×48 mm m=16-17 mm. Turning and boring of semi-finished tubes with dimensions of 550×45×5000-5300 mm to marketable tubes with dimensions of 530×25-28×5000-5300 mm, and semi-finished tubes with dimensions of 550×48×4600-5000 mm to marketable tubes with dimensions of 530×28-30×4600-5000 mm is performed.

EFFECT: production of seamless tubes with geometrical dimensions exceeding requirements of the existing technical specifications.

2 cl, 1 tbl