Among the various casting processes, stainless steel are mainly cast by investment casting or lost wax casting process, because it has much higher accuracy and that's why the investment casting is also named precision casting.
Stainless steel is the abbreviation of stainless and acid-resistant steel. It is called stainless steel that is resistant to weak corrosive media such as air, steam, and water. Corrosion steel is called acid-resistant steel.
Due to the difference in chemical composition between the ordinary stainless steel and acid-resistant steel, their corrosion resistance is different. Ordinary stainless steel is generally not resistant to chemical media corrosion, while acid-resistant steel is generally non-corrosive. The term "stainless steel" not only refers to a single type of stainless steel, but also refers to more than one hundred industrial stainless steels. Each stainless steel developed has good performance in its specific application field.
Stainless steel is often divided into martensitic stainless steel, ferritic stainless steel, austenitic stainless steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel according to the state of microstructure. In addition, according to the chemical compositions, it can be divided into chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel, etc.
In casting production, most of the stainless steel castings are completed by investment casting. The surface of stainless steel castings produced by investment casting is smoother and the dimensional accuracy is easier to control. Of course, the cost of investment casting stainless steel parts is relatively high compared to other processes and materials.
Investment casting, also called precision casting or lost wax casting, is widely used as it offers asymmetrical casting with very fine details to be manufactured relatively inexpensively. The process involves producing a metal casting using a refractory mould made from a wax replica pattern. The steps involved in the process or the lost wax casting are:
• Create a wax pattern or replica
• Sprue the wax pattern
• Invest the wax pattern
• Eliminate the wax pattern by burning it (inside the furnace or in hot water) to create a mould.
• Force molten metal pour into the mould
• Cooling and Solidification
• Remove sprue from the castings
• Finish and polish the finished investment castings
Post time: Jan-06-2021