Thermal Treatments

Quench & Temper 

The process is primarily used for ferrous alloys to harden the material by austenitizing and then cooling at a rate that allows for a substantial amount of austenite to transform to martensite.  Century Sun Metal Treating offers all major hardening processes to provide this service e.g. salt bath hardening, vacuum hardening, atmosphere hardening etc.

Induction Hardening

A surface hardening process in which only the surface layer of a suitable ferrous alloy is heated by electromagnetic induction to above the upper critical temperature and then immediately quenched.


Absorption and diffusion of carbon into solid ferrous alloys by heating to a temperature above the Ac3, and providing contact with a suitable carbonaceous material and atmosphere. A form of case hardening that produces a measurable carbon gradient extending inward from the surface.


A case hardening process in which a ferrous material is heated above the lower transformation temperature in a gaseous atmosphere  that promotes the absorption of carbon and nitrogen by the surface and through diffusion creates a concentration gradient.

Ion Nitriding 

Century Sun offers two  proprietary surface treatments that are classified as Ion Nitriding, one is CaseTuff* and the other is CaseWear*.  This thermal diffusion case hardening process is designed to add significant value by extending tool life on both ferrous and stainless steel grades of material.  CaseWear* is designed for cold work applications and CaseTuff* provides a more ductile layer for hot work steels. Distortion is also minimized with this process due to the relatively low temperature which is held below the Ac1 for ferritic steels.  Finished tooling and components are common to this process.

Marquench & Austempering

A treatment for ferrous alloys in which a part is quenched from the austenitizing temperature at a rate fast enough to avoid the formation of pearlite of ferrite and then held at a temperature just above the Ms until transformation to bainite is complete.

Precipitation Hardening

Hardening of a material caused by the precipitation of a constituent from a supersaturated solid solution.

Stress Relieving

Heating of the work piece to a suitable temperature for the grade of material, then holding the long enough to reduce residual stresses.


A thermal treatment primarily used to soften metallic materials, but also used to  simultaneously produce changes in other properties or microstructure.


Heating a ferrous alloy to a suitable temperature above the transformation range and then cooling in air to a temperature substantially below the transformation range.

Cryogenic Treating

Our state of the art “cold chamber” can accommodate load sizes to 36" x 36" x 50" up to a 4,000 lb. hearth capacity. Thermal processes to -300° Fahrenheit are vertically integrated into the heat treating cycle completely transforming and refining the heat treated microstructure which extends tool life, secures dimensional stability and achieves the optimum mechanical and metallurgical properties obtainable within the industry today.