Hydrogen furnace brazing eliminates the need for fluxes to protect braze joint surfaces from oxidation. In a hydrogen atmosphere, oxides on parts being heated to braze temperature tend to dissociate, and are subsequently flushed from the retort with the positive flow of hydrogen, so parts emerge from the retort bright and clean. Hydrogen furnace brazing also allows for precise control of the entire brazing cycle and, with the aid of imbedded or attached thermocouples, ensures an exacting braze joint temperature.
Thermal-Vac's hydrogen furnace has two retorts allowing the unloading and set-up of one while the other is being used to process parts. After parts are loaded, air is vacuumed out of the retort and the retort is then purged with inert gas prior to introduction of hydrogen gas. Oxygen sensors prevent premature introduction of the hydrogen into the retort.
Typically Thermal-Vac uses copper braze filler metal in hydrogen for brazing stainless or carbon steel assemblies.
Industry standards for hydrogen brazing include:
- Mil-B-007883C, Type II
- AWS C3.6: 1999
