A Salt Bath is a largely overlooked alternative to many types of furnace. It has many advantages and a few disadvantages over conventional atmosphere furnace.

The heating medium of a salt bath is the salt itself. This is heated to the required temperature by either external heating, over the side submerged elements, or submerged electrodes. When a load is submerged into the salt it is heated rapidly and uniformly to the required temperature. The salt also doubles as a protective atmosphere during the heating cycle. When the load is withdrawn a thin covering film of salt will protect it.

Temperatures available can range from around 150⁰c to 1300⁰c. The low temperature ranges can be heated by external heating to a salt pot, or over the side submerged sheathed wire elements. Above 600⁰c, over the side submerge elements suffer severely from corrosion at the salt-air interface (where the elements/electrode enter the salt). At these temperatures and above we recommend totally submerged electrodes, which enter the bath through the side-wall (below the salt-air interface) and apply heat by using the salt itself as the resistance element. This method has many advantages over any heating method that enters the bath over the side wall. Not only does it eliminate the electrode corrosion at the salt-air interface, but also reduces the top losses (heat escaping from the top of the bath) because the bath can be smaller. It also aids salt circulation and agitation due to electro-dynamic forces. The totally submerged electrode design was developed by UPTON-Industries Inc (of Michigan, U.S.A.), and HIE are exclusive licensees of this system in Britain.

Salt Baths Can Be Used For:-

Carburising

Nitriding Cyanide Hardening

Austempering

Aluminising

Hardening

Annealing

Tempering

Brazing

Etc…