PRODUCTION OF BILLETS WITH OUTER AND INNER PLATING PLIES FROM CORROSION-RESISTANT STEELS AND ALLOYS FOR PRODUCTION OF SEAMLESS THREE-LAYER HOT- AND COLD-ROLLED COMMERCIAL AND REROLLED LONGER-LIFE PIPES FOR GAS AND GAS CONDENSATE EXTRACTION IN HYDROGEN SULPHIDE-BEARING MEDIA, ITS TRANSPORTATION AND GENERAL PURPOSE PIPES

摘要

FIELD: process engineering.SUBSTANCE: invention relates to production of seamless three-layer pipes with outer and inner plating layers. Ingots are cast by ESR from "10??2???"-grade steel. Central bore is drilled therein and ingots are heated to ductility temperature. First, said ingots are rolled at helical rolling stand to sleeves. The latter are rolled at Pilger mills to thick-wall hot-rolled pipes to be turned and pierced to pipe billets of required size. 08X18H10T-grade steel ply is built up on inner layer while bimetallic billets ate bored to commercial pipes with preset depth of walls of parent metal and plating plies. Note here that outer and inner surfaces of 219-630×1200-3200±50 mm pipe billets are coated by electric welding with plating plies of rustproof steels and alloys, their depth being defined by mathematical relationships.EFFECT: lower metal and alloy input, pipe longer life.3 cl