The Debate: Cast vs Wrought, Which is Better?

Both castings and wrought alloys have their place in the heat treating world, but learn where and when to use each.

For example, cast materials typically have higher yield, tensile and creep strengths and are often used for these properties. However, in many cases, castings are used in an application where a wrought product should be used simply because the initial cost of a casting is typically less expensive when in actuality, a company would save a significant amount of money by considering the life cycle cost of their materials. The list below only covers a few of the points comparing the two types of material processing.

 

Cast

Wrought

 

Creep Strength

X

 

Similar compositions are inherently stronger at high temperatures in the cast forms over wrought grades. This is because of the microstructure, as well as the higher carbon contents that are typical in a casting.

Thermal Fatigue

 

X

Thinner sections reduce the amount of internal thermal stresses within the material. This allows for inherently greater ductility in wrought materials that promote better resistance to thermal cycling and thermal shock.

Surface Finish

 

X

The smooth surface of a wrought alloy helps avoid focal points for accelerated corrosion by molten salts or carbon deposits.

Repairability

 

X

To repair any stainless steel or nickel alloy, the material must have retained some amount of ductility. While cast parts can fail from corrosion, the most common failure is brittle cracking making them very difficult to weld repair.

 

In all fairness, there are some applications where a casting is needed; most of which require extremely high strengths. Take a look at this document to get an idea of the strengths and weaknesses of both cast and wrought materials.  If you would like to have some questions answered, please email our engineers at metallurgicalhelp@rolledalloys.com.

Both castings and wrought alloys have their place in the heat treating world.