METHOD FOR PRODUCTION OF SEAMLESS HOT-DEFORMED BOILER THICK-WALLED PIPES WITH SIZE OF 377×50 AND 465×75 mm IN PIPE-ROLLING PLANTS WITH PILGER MILLS FOR PIPELINES OF HEAT COAL BLOCKS WITH SUPERCRITICAL STEAM PARAMETRES

摘要

FIELD: technological processes.;SUBSTANCE: invention relates to method for production of seamless hot-deformed boiler thick-walled pipes with size of 377x50 and 465x75 mm in pipe-rolling plants with Pilger mills for pipelines of heat coal blocks with supercritical steam parametres (T≥600°C and P=300 atm) and for live steam pipelines. Method includes smelting of conversion pipe billets in the form of solid ingots with size 560x1750±50 and 620×1750±50 mm or hollow bars with size of 620×200int.x2000-2100 and 620×320int.×2000-3200 mm with steel of grade 10X9V2MFBR by method of electroslag remelting (ESR), drilling of central hole with diametre of 100±5.0 mm, heating of billets up to plasticity temperature, their broaching into cartridges in slant rolling mills on mandrels, diametre of which is selected depending on geomatric dimensions of cartirdges, rolling of cartridges in Pilger mills into pipes of specified size with draws, depending on diametre and thickness of wall. Dependent claims provide modes of mechanical and thermal treatment of solid and hollow bars.;EFFECT: invention will make it possible to master production of pipes with dimensions of 465x75 mm, to reduce power inputs, consumption ratio of metal, to improve mechanical properties of pipe metal, compared to forged billet of steel grade 10X9MFB-Sh, to considerably increase durable strength of pipe metal at T≥600°C and duration 10⁵ and to reduce cost of boiler pipes.;8 cl, 1 tbl