Alloy steel casting is a steel casting process that alloys a variety of elements with a total amount between 1.0% and 50% to improve its mechanical properties. Alloy steels are divided into two categories: low alloy steels and high alloy steels. Most commonly, the alloy steels used in investment casting are low alloy steels.
Strictly speaking, every steel is an alloy, but not all steels are called “alloy steels”. The simplest steel is an alloy of iron (Fe) and carbon (C) (about 0.1% to 1%, depending on the type). However, the term “alloy steel” is the standard term and refers to steel to which other alloying elements besides carbon have been intentionally added. Common alloying elements include manganese (the most common one), nickel, chromium, molybdenum, vanadium, silicon, and boron. Less common alloying elements include aluminum, cobalt, copper, cerium, niobium, titanium, tungsten, tin, zinc, lead, and zirconium.
With investment castings made of alloy steels, we obtain many properties including (compared to carbon steels): strength, hardness, toughness, wear resistance, corrosion resistance and hardenability. Of course, heat treatment will help improve some of these improved properties if investment casting cannot be met directly.