RU2007127578A - PIPE PROCESSING OF ELECTRIC SLAG RESTINATION FROM LOW-PLASTIC STEEL WITH A BORN CONTENT OF 1.3-1.8% FOR ROLLING TRANSITION PIPES TO TUBE-ROLLING PLANTS WITH PILGRIM MILLS AND METHOD OF ITS PRODUCTION - Google Patents

Claims (7)

1. Pipe billet of electroslag remelting of low-ductility steel with a boron content of 1.3-1.8% for rolling conversion pipes in tube-rolling plants with pilgrim mills and a method for its manufacture, consisting of an ingot of steel grade 04X14TZR1F, characterized in that the billet is hollow, and the end sections corresponding to the bottom and shrink ends are made of ductile carbon steel grades. 2. The tube stock according to claim 1, characterized in that the dimensions of the workpiece, shrink and bottom ends are determined from the expressions L _Y = (0.05-0.06) L _Z , L _D = (0.12-0.15) L _Z , D _{N.D.K ..} = (1,02-1,04) D _{Z.N ..} , D _V.D.K. = (0.96-0.97) D _Z.V. , D _N.U.K. = D _Z.N , D _V.U.K. = D _Z.V. , where L _З = 2100 ± 50 is the length of the hollow billet of their steel grade 04X14TZR1F, mm; D _Z.N. = 465 ± 5.0 - the outer diameter of the billet from steel 04X14TZR1F, mm; D _Z.V. = 295 ± 5.0 - the inner diameter of the billet from steel 04X14TZR1F, mm; L _U - the length of the plastic carbon extension from the shrink end of the workpiece, mm; L _D - the length of the plastic carbon extension from the bottom end of the workpiece, mm; D _N.U.K. - the outer diameter of the carbon extension from the shrink end of the workpiece, mm; D _V.U.K. - the inner diameter of the carbon extension from the shrink end of the workpiece, mm; D _N.D.K. - the outer diameter of the carbon extension from the bottom end of the workpiece, mm; D _{V.D.K ..} - the inner diameter of the carbon extension from the bottom end of the workpiece, mm 3. The tube stock according to claim 1, characterized in that the carbon extension from the shrink end of the blank is made in the form of a cone, the dimensions of which are determined from the expressions L _W.K. = (0.6-0.75) L _Y , D _{U. cone} = (0.8-0.85) D _Z.N. . 4. A method of manufacturing tube billets by electroslag remelting from low-ductility steel with a boron content of 1.3-1.8% for rolling steel tubes at tube-rolling plants with pilgrim mills, including casting ingots of 460-480 × 1700 ± 50 mm in size, drilling a central hole with a diameter 100 ± 5.0 mm, heating them to the temperature of ductility, piercing in the oblique rolling mill on a mandrel with a diameter of 275 mm into sleeves of 470-480 × 290 in. × 2450-2550 mm in size and rolling the sleeves on a pilgrim mill into 290 × 12 pig tubes × 22000-23000 mm, with pipe fittings weaves are cast with hollow sizes of 475 ± 5.0 × 285 in. ± 5.0 × 2500 ± 50 mm, and the bottom and shrinkage parts of hollow ingots forming piligrim heads and seed ends during rolling of pig tubes are cast from plastic carbon steel grades. 5. The method according to claim 4, characterized in that the hollow tube ingots are bored and turned into tube billets with a surface finish of Rz ≤40 μm from the shrink side to a size of 465 ± 5.0 × 295 in. ± 5.0 × 2500 ± 50 mm with a shift towards the bottom of the plastic carbon steel by 50-80 mm. 6. The method according to claim 5, characterized in that when turning, the transition at the bottom end of the workpieces from the base metal to ductile carbon steel is performed smoothly in the form of a truncated cone over a length of 50-80 mm. 7. The method according to claim 5, characterized in that the ends of the pipe blanks corresponding to the shrink ends are tapered.