METHOD OF FABRICATION OF COMMERCIAL PIPES WITH SIZE 406,4+0,4/-0×14,38+0,28/-0,72 mm FROM TITANIUM ALLOY Gr 29 FOR FURTHER USE IN GEOTHERMAL WELLS CONSTRUCTION

摘要

FIELD: metallurgy.;SUBSTANCE: ingots are cast with further forging and machining to billets 585×1900±25 mm. In billets a central hole with diameter 90±5 mm is drilled. Al₂O₃ schooping and heating in mufflers to temperature 1150-1180°C are performed. The billets are pierced in helical rolling mill on the mandrel with diameter 375 mm to shells 585xID390×3300-3390 mm with drawing µ=1.76. The shells are rolled on the Pilger mill to the tube stocks with size 426×34×10500±250 mm with drawing µ=3.56-3.58 and fit as per diameter Δ=27.2%. Machining is performed, i.e. turning and boring of pipes with allowance Δ_me=19.3-20.3 mm at ends and allowance Δ_mb=19.6-21.4 mm along pipe body. Process wastes are removed from pipes by hot cutting saw, tube stock is straightened under temperature of roll heating on 6-hi straightening unit by two-three passes to maximum degree of curvature 6 mm per full pipe length. The tube stick is turned and bored to commercial dimensions 406.4+0.4/-0×14.38+0.28/-0.72 mm, at ends through length 520+10 mm, for buttress thread making, and along pipe body to size 406.4+4.0/-2.0×14.3 8+0/-1.8×10000+1007-0 mm.;EFFECT: implementation of new type of tube stock and commercial long pipes out of the titanium alloy Gr 29 to construct the geothermal wells.;1 dwg