Solution Annealing

Capabilities

Therm Tech can accomplish the solution annealing heat treatment in open fire, atmosphere and vacuum depending on material and required surface finish.  All furnaces meet AMS 2750 class 5 specifications for temperature uniformity and pyrometry.

Size capabilities depend on atmosphere requirements and temperature.  Maximum open fire capacity is 162” X 96” x 48”, maximum vacuum capacity is 72” x 36” x 36” and maximum atmosphere capacity is 96” x 60” x 48”.

Process

The process of solution annealing is typically applied to stainless steels and high nickel alloys for heat resisting and corrosion resistant applications.  They are generally high temperature processes requiring rapid quenching. 

The most common application of the solution annealing process is used for austenitic stainless steels.  Solution annealing 300 series stainless steels improves the corrosion resistance by putting carbides into solution in the microstructural matrix.  A rapid quench inhibits carbides from reforming during cooling.  Austenitic stainless steels are not solution annealed to appreciably change mechanical properties.

Many other materials are solution annealed for reasons of changing mechanical properties.  Some materials such as 17-4 stainless steel and some Inconels  are solution annealed as a pretreatment for age hardening ultimately providing the required mechanical properties for the part application. 

Recommendations

Selection of the proper atmosphere is a critical factor when choosing proper processing parameters for solution annealing.  If no oxidation is allowable a vacuum process should be selected.

Distortion and prevention of distortion is another important aspect.  Austenitic materials require rapid quenching which can cause considerable distortion.  There is some ability to mitigate this outcome but it is a good idea to discuss these potentials prior to heat treatment.