Salt Bath Process

As the name implies, this type of processing is carried out using baths of
different salt mixes with different melting points. The salts are melted in a heat resistant pot and once fluid they are used as a heating medium. As a hot liquid it exhibits a natural convection and has good temperature uniformity and ease of control of temperature by immersion thermocouples.

Having different furnaces at various temperatures gives the versatility associated
with salt bath processing. Individual furnace temperatures can be adjusted to
suit requirements and the items are manually moved from furnace to furnace.

Having achieved the hardening temperature, the jobs are removed and quenched as required. The quenching medium, being separate from the heating furnaces can
be whatever is required for that individual process e.g. air, salt, oil or water.

After processing, the parts remain covered with a layer of salt which needs to
be cleaned (washed & blasted). This does make the process unsuitable for
parts where surface finish is important and little or no further machining is to
take place. If subsequent surface treatments are to take place, vacuum processing may be more suitable.

This process is highly suitable for parts where subsequent grinding is to take place.