METHOD OF PRODUCING SEAMLESS HOT-WORKED BOILER AND STEAM PIPES Russian patent published in 2012 - IPC B21B19/04 

FIELD: process engineering.

SUBSTANCE: invention relates to rolling of pipes for steam boilers, steam conduits and manifolds from ingots of electroslag remelting of "10Х9К3В2МФБР-Ш"-grade steels at pipe rolling plants with pilger mills. Proposed method comprises smelting rerolled tubular billets by electroslag remelting to solid ingots, machining, drilling central bore and heating ingots to plasticity temperature. Note here that ingots are placed in continuous furnace and arranged in two rows, heated to preset temperature with turning and held at said temperature with uniform turning from eighth to fourth window. Ingots are turned from fourth window to furnace pit and directed from said furnace to conversion at helical rolling mill into rough tube on mandrels with diameters selected depending upon rough tube geometrical sizes. Rough tubes are rolled at pilger mills into pipes. Note here that ingots are uniformly heated to 1160-1180°C at the rate of 3.2-3.3°C/min with turning and held at said temperature for 60-80 min. Ingots are converted at helical rolling mills into rough tubes at mandrels with diameter charging of Δ=6.7% and rolling-out of 1.43-1.57 µ, while rough tube rolling is performed with diameter reduction of Δ=41.0% and rolling-out of 4.36-7.66 µ.

EFFECT: higher mechanical properties, reduced consumption of metal.

2 cl, 1 tbl