Stainless steel is a popular choice for many safety-critical applications that require durability, integrity and strength. However, there are a wide variety of stainless steels, each suitable for different applications. If you're not sure which stainless steel is best for your application, keep reading. We will discuss the most commonly used stainless steels in casting and how to choose the right stainless steel.
Let's start by discussing the overall advantages of stainless steel casting.
The benefits of stainless steel
Investment casting is often used to create complex shapes with tight tolerances. Stainless steel is used in investment casting, especially when high corrosion and wear resistance is required. Its high corrosion resistance makes it ideal for many military, medical and industrial applications.
The benefits of stainless steel vary by alloy. All stainless steels contain at least 10.5% chromium, but some may contain more depending on the application. Higher chromium content results in higher corrosion resistance. Other alloy components include molybdenum, nickel, titanium, aluminum, copper, nitrogen, phosphorus and selenium.
Most commonly used stainless steel
While many different types of alloys can be used in the investment casting process, 304 (CF-8) is the most commonly used grade. 304 stainless steel, sometimes referred to as 18/8 steel, is a low carbon (0.08% or less) alloy steel typically containing 18% chromium and at least 8% nickel. This makes it resistant to scaling and corrosion at high operating temperatures. Low carbon prevents carbide precipitation during welding, allowing welding without annealing even in potentially corrosive environments.
Additionally, all 300-grade stainless steels contain nickel, which helps them maintain their austenitic structure when cooled from high temperatures. Austenitic steels tend to be highly ductile and easy to weld.
304 is commonly used to manufacture high strength components in harsh environments for safety critical industries. Other widely used stainless steel grades include: 316, 304L/316L, 410 and 416 and 17-4.
