Tham khảo tài liệu 'volume 06 - welding, brazing and soldering part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | FURNACE BRAZING IN DRY HYDROGEN FURNACE CONTINUOUS CONVEYOR A FIXTURES NONE FURNACE TEMPERATURE C F 980 5 1800 10 BRAZING temperature C F 925 5 1700 10 HYDROGEN DEW POINTS C F -75 -100 B -60 -70 C HYDROGEN FLOW RATE M3 H FT3 H 11 400 FILLER METAL D BAG- 13 JOINT POSITION DURING BRAZING HORIZONTAL CONVEYOR TRAVEL SPEED M H FT H 9 30 TIME AT BRAZING TEMPERATURE MIN E 5 PRODUCTION RATE ASSEMBLIES H 120 A ELECTRICITY HEATED 60 KW CONSTRUCTED WITH HEATING CHAMBER HIGHER THAN ENTRANCE AND DISChArGE Ends. B INCOMING. C exhaust. D IN FORM OF 1 MM in. diameter WIRE-RING preforms. FIG. 3 RETAINER ASSEMBLY FURNACE BRAZED WITH BAG-13 FILLER METAL The components were vapor degreased assembled keeping their outside diameters concentric and spot welded to make them self-jigging at four locations 90 apart Fig. 3 . A ring of brazing filler metal wire in a 1 mm in. diameter was preplaced at the joint and assemblies were loaded two-across on the mesh belt of a conveyor-type furnace. The heating chamber of the furnace was elevated from the entrance and discharge level to conserve the lighter-than-air hydrogen and to prevent oxygen in the atmosphere from mixing with the hydrogen which could either raise the dew point or cause an explosion. Quality standards for brazed assemblies which were checked by 100 visual inspection required that the joint exhibit full braze penetration 360 fillets on both sides of the joint and be pressure-tight. Example 4 Use of a Gold Brazing Filler Metal for Brazing in an Aerospace Heat Exchanger. In the fabrication of a high-reliability heat exchanger for manned space flights 2552 fins of mm in. thick type 347 stainless steel were brazed to mm in. thick type 347 stainless steel side panels as shown in Fig. 4. The 5104 fin-to-panel joints had to be strong and corrosion resistant. FURNACE BRAZING IN DRY HYDROGEN FURNACE BELL A FIXTURES SEE ILLUSTRATION BRAZING TEMPERATURE C F 1015 I860 HYDROGEN DEW POINT MAX C F -60 -80 B .
