Stainless steel is a generic name used for a group of ferric alloys which are rust-resistant. It has a passivation layer that safeguards it from moisture and air. This rust-resistance property makes it suitable to be used for aqueous, food services, and other outdoor applications. This article is regarding the manufacturing of stainless steel in steel casting foundry.
Casting stainless steel is generally made and finished in a foundry or under the supervision of a foundry. If there is a small-scale need to produce casted stainless steel, then the casting is sent to relevant factories for the task of fulfilling. assembly. Stainless steel is produced using raw materials of iron ore, chromium, silicon, molybdenum, and other metals. These materials are melted together to form stainless steel in investment casting company
The collection of these chemical elements produces a strong alloy. The proportion of each element determines the type of steel yielded. Iron to other materials ratio determines the resistivity of metals to corrosive materials and other physical properties like hardness, shear modulus, etc. Each different type of steel has a “grade” e.g., grade 316 stainless, grade 304 stainless, etc. Here are the steps showing the manufacturing of stainless steel in Steel Casting Foundry.
- Raw Steel Melting:
At first, all the raw materials are subjected to the electric furnace for melting. This process takes 8-12 hours.
- Excess Carbon Removal:
Then, the molten metals are pelted into argon oxygen decarburization or vacuum oxygen decarburization system which removes extra carbon from molten metal. Depending on the amount of carbon removed, this step yields a variant of alloy e.g., 304 versus 304L stainless steel. The amount of carbon in steel determines the hardness and tensile strength of steel produced.
To get fine quality of steel, the molten metals are stirred to uniform and remove certain materials from the molten mixture. This process helps in getting a smoothened and desired quality steel.
- Metal Forming:
After the mixture cools, the mixture is then passed through a number of processes which include hot rolling. This helps the steel getting a rough shape and can be used to create blooms or billets of metal. To create billets or blooms of metal with precise dimensions, the steel can be let to cool or rolled.
The stainless steel’s physical properties can be altered and to relieve internal stress, it is heated and then let to cool under specific conditions (this process is known as annealing). After annealing, the steel is descaled so that its oxide layer protection remains.
- Cutting And Transformation Into Different Shapes:
After the annealing phase, the stainless steel is passed through a number of cutting and shape transformation stages to get the desired end product for use. The processes used for cutting depends on the size and shape of bloom/billet and the desired product. For example, for making thick metal plates, the steel can be cut mechanically with huge shears of metal. While for thin metal sheets, laser cutting machines or CNC punches can be used to cut shapes.
- Surface Finishes application:
The steel manufacturer then applies different surface finishes to blooms, billets, wires, or sheets before their delivery to other manufacturers. The type of finish use depends upon the intended use of steel. The most common finish is the simple grinding of the surface to smoothen the layer and to remove impurities.
In this article, the manufacturing of stainless steel in steel casting foundry is discussed in detail. Stainless is rust-resistant but this property depends upon the passivation layer quality. If this layer is disturbed chemically, then the stainless steel is at the risk of rusting. While installing stainless steel, care must be taken as steel tools can alter the steel surface chemistry by making the surface vulnerable by leaving iron deposits. Stainless steel surface maintenance should also be regularly undertaken if it is exposed to salt, iron, or scratches.