Normalizing

ThermTech is proud to offer normalizing heat treatments for investment castings. The process is one of the simplest that can be employed on cast products to homogenize grain structure, improving machinability and response to subsequent heat treating processes.

Capability

All normalizing processes are run out of batch-type furnaces for optimum process and lot control. Our largest furnace capable of performing normalizing heat treatments has internal working dimensions of 86”W x 182”L x 51”H. All ThermTech furnaces are certified to AMS 2750, ensuring optimal temperature uniformity during the hardening process.

Process

Investment castings are usually cooled in ceramic molds as part of the casting process.  As a result the cooling times can be long and may create undesirable microstructures and decarburization.   

The normalizing process is commonly applied in concert with a carbon-restoration cycle in order to produce a homogeneuous micro-structure and restore lost surface carbon in the castings.  

During normalizing, the castings are typically heated to a temperature slightly above the austenitzing temperature – usually 1600°F – 1750°F to promote atomic mobility that enhances homogenization of the steel. The forgings are then held at the normalizing temperature for several hours and are usually cooled in still air. The cooling rate can be altered depending on the final hardness needed.

ThermTech offers normalizing for investment castings for any steel grade, but the following are the most common:

  • Normalizing 4140 Steel
  • Normalizing 4340 Steel
  • Normalizing 8620 Steel
  • Normalizing 4130 Steel

If a clean finish is required after normalizing, ThermTech offers several different blasting services to remove any oxide present.

Contact a sales representative today to discuss how our normalizing services can benefit your forged products!