Steel

Spheroidize annealing produces microstructure of globular carbides in a ferritic matrix. This microstructure is
achieved in a few different ways:

Shot blasting is the process in which a blasting media (shot) is used to clean the surface of steel, eliminating old coatings, rust, scale, etc.

Quench and Temper process provides strength and toughness throughout the part being processed. It is a two-
stage heat treat process that includes hardening and tempering processes.

 

 

 

 

 

 

Stage 1 – Pickling:
The purpose of pickling is to remove contaminates from the surface of the steel such as scale, stains, or rust.
Sulfuric acid is commonly used for its high rate of corrosive properties. The acid will attack the steel surface
creating soot and will leave the surface of the steel texturized for post processing.

Phosphates are available in light and heavy versions with a base of zinc, iron or manganese. In addition, there
are several types of lubrications available like sodium stearate, polymer and molybdenum-disulfide. Depending
on the application, one can choose the appropriate combination of phosphate and lubrication to optimize the
forming operation.

Normalizing is a heat treat process in which steel is austenitized (heated above a critical temperature), held for a
specified time, and then cooled in air.

 

Isothermal anneal is a two-stage process involving austenitizing the material first at preferred temperature and
subsequently cooling to and holding at a specific temperature to complete the transformation.

The annealing process involves heating up the material slightly above its austenitizing temperature and then controlled cooling it from there. In annealing, the material can be cooled in the furnace either isothermally or non-isothermally. By controlling the cooling rate the hardness and the ductility of the material can be controlled.

Annealing brings the material to its initial strain-free state via three stages – recovery, recrystallization and grain growth.