Investment casting and machining stainless steel exhaust manifold

Stainless steel is an abbreviation for stainless steel and acid resistant steel. Called stainless steel, it is resistant to mild corrosive media such as air, steam, and water. Corrosion resistant steel is called acid resistant steel.

Since ordinary stainless steel and acid-resistant steel have different chemical compositions, they have different corrosion resistance. Traditional stainless steels are generally not resistant to corrosion in chemical environments, while acid-resistant steels are generally non-corrosive. The term “stainless steel” refers not only to one type of stainless steel, but also to more than 100 industrial stainless steels. Each stainless steel developed provides excellent performance in specific applications.

Stainless steels can be classified into martensite-based stainless steels, iron-containing stainless steels, austenitic stainless steels, austenite-based iron-containing (double) stainless steels, and precipitation-hardened stainless steels, depending on the state of the microstructure. . a bunch of. In addition, it can be classified into chrome stainless steel, nickel chrome stainless steel, nitrogen chrome manganese stainless steel, etc. depending on the chemical composition.

In the foundry industry, most stainless steel castings are made by investment casting. Investment Stainless steel castings have a smoother surface and dimensional accuracy is easier to control. Of course, the precision casting cost of stainless steel parts is relatively high compared to other processes and materials.

Investment casting, also known as precision casting or investment casting, is widely used because it allows for asymmetric casting with very small parts at relatively low cost. This process uses a refractory mold made from a wax lance to make a metal casting. The steps involved in the investment casting process are:

• Create a wax model or replica
• Color the wax pattern
• Apply wax model
• Bake the wax model (in orb or hot water) to create the shape and remove the wax model.
• Pour the molten metal into the mold
• Cool and harden
• Remove the sprue from the casting.
• Finish and polish the finished investment casting.