Material selection is a crucial part in any casting process. Choosing the right casting material is so important because the material defines the chemical and mechanical properties of the cast component, can significantly influence the working performance of the component, and ensures that part functions properly. The corrosion resistance of the metal is a key characteristic to consider when choosing a right metal to cast a part, especially for those parts working in special environment, such as marine application.
Corrosion resistance is the ability to prevent environmental deterioration by chemical or electro-chemical reaction. The chemical composition of a casting metal will decide the ability of corrosion resistance. Kindly remind that any cast alloy may corrode under certain circumstances, even if cast stainless steel.
What Are the Top 2 Corrosion Resistant Casting Metals?
CFS Foundry is experienced in the casting of different metals, due to our rich experience in casting field, we well know the features of each casting metal. Below are the top casting metals with good corrosion resistance:
Stainless Steel Alloys
Stainless steel is the most common of the corrosion resistant casting metal, which contains a minimum of 10.5% chromium. The chromium oxidizes quickly to form a protective layer of chromium oxide on the metal surface. This oxide layer resists corrosion, while at the same time prevents oxygen from reaching the underlying steel. Other elements in the alloy, such as nickel and molybdenum, add to its rust-resistance.
Since this material has a high melting point and can sustain and support high pressure, stainless steel casting is ideal to creat stainles steel components for marine, food machinery, bathroom fittings, etc.
CFS Foundry can investment cast different types of stainless steel alloys, including martensitic stainless steel, austenitic stainless steel, precipitation hardening stainless steel, and duplex stainless steel. For stainless steel parts for marine application, 316 stainless steel casting is suggested for its good corrosion resistance in marine enviroment. Our passivation process can help to improve the corrosion resistance of stainless steel castings.
Alumimum Alloys
Many cast components are made from aluminum, such as car and bike parts. This is due to its light weight, but also for its resistance to corrosion. Aluminum alloys contain almost no iron and without iron, the metal can’t actually rust, but it does oxidize. When the alloy is exposed to water, a film of aluminum oxide forms quickly on the surface. The hard oxide layer is quite resistant to further corrosion and protects the underlying metal.
Aluminum casting is frequently used to produce lightweight metal parts in aerospace applications, automotive application, marine application, and other situations where a high-performance material is required. Compared to stainless steel casting, aluminum casting is more affordable, while keeping in mind that stainless steel has its own advantages.
CFS’ aluminum casting ability is another bright spot, common aluminum casting alloys are: ASTM A356 and ASTM A380. Our gravity die casting and pressure die casting processes can cast out aluminum parts in any structure. The hard anodization process can further improve the corrosion resistance of aluminum castings.
If you have a casting part requiring good corrosion resistance, contact our foundry for a full solution!