Solution Annealing Heat Treatment Process

Solution annealing is a high temperature heat treating process performed on steels, particularly austenitic stainless steels in the 300 series.  The castings are held at a temperature and time sufficient to bring the carbon in the steel into a solid solution.  The material is then quickly cooled to lock the carbon in the solid solution. The solution anneal process results in a casting in the most corrosion resistant and ductile condition.


ThermTech has multiple solution annealing furnaces to meet your heat treating needs.  All solution annealing equipment is certified to AMS 2750 Rev E class 5 with temperature uniformity of +/-25F.  With furnace dimension up to 60”W X 42”H X 92”L, ThermTech has the capability to meet you solution annealing needs.


Solution annealing is a high temperature heat treating process.  The material is heated to temperatures ranging from 1900F to 2200F for a period of time sufficient to reach temperature uniformity throughout the largest cross section bringing the carbon in the material into a solid solution.  The ultimate solution annealing temperature is dependent on the material.  After soaking for the appropriate time, the material is quickly cooled to prevent the carbon from coming out of solution.  Systems for cooling the castings include fan cooling, oil equivalent polymer quenching, polymer quenching and water quenching. The quench method is a function of material, section sixe and distortion sensitivity.  
ThermTech employs two staff metallurgists and a process development team to custom design a solution annealing process to meet the product and specification requirements.  ThermTech has the capability to perform the solution annealing process in vacuum for work that has stringent cleanliness requirements.


Solution annealing results in a casting in its most ductile state.  Surface hardness is used as a proxy measure for material ductility.  Where surface hardness values are required, the hardness requirement must be documented on the purchase order.  Hardness values are typically stated as maximum hardness value.  Meeting hardness ranges, both upper and lower hardness requirements, is a function of the material chemistry and the solution annealing process.  Please contact our sales group at if you have any questions about post solution anneal material hardness values.
If the material has straightness requirement, insure the tolerances are included on the purchase order and our process development team will create a process to minimize potential distortion during the solution annealing process.