Heat Treatment Technology of Stainless Steel in Investment Foundry

Jan 02, 2023

Heat Treatment Technology of Stainless Steel in Investment Foundry

(1) Martian loose iron stainless steel: This type of stainless steel has a body centered cubic structure (BCC) that can attract magnets and make them quenched from the Austen temperature. This type of stainless steel has the best corrosion resistance, but the material is hard and brittle. Tempering can increase the ductility, but the corrosion resistance will decrease, especially when tempering between 450 ℃ and 650 ℃, It will cause carbon atoms in the crystal lattice gap to diffuse and precipitate chromium carbide and form a network of chromium, which will cause the consumption of chromium elements in the adjacent area to reduce the chromium composition, prevent the formation of a protective film, and lose the corrosion resistance, so special attention should be paid. The following is the heat treatment temperature of various stainless steel materials of Matian loose iron.

(a) The temperature of 403410416se is 650-750 ℃.

(b) The temperature of 414 is 650-730 ℃.

(2) Fat grain iron stainless steel: This stainless steel body centered cubic structure (BCC) can attract magnets, which are usually used in the automobile industry or chemical industry. The strength will not change due to heat treatment, but can be increased by cold processing.

(3) Austen iron stainless steel: This stainless steel face centered cubic structure (FCC) has no effect on magnets. As mentioned above, this kind of material is easy to process, so after processing, it can eliminate the residual stress of the material and apply different heat treatment.

(4) Precipitation hardening stainless steel: this type of stainless steel is quenched at high temperature and then heat treated at low temperature. The strength or hardness of this type of stainless steel can be improved due to the precipitation of aluminum or copper elements in the material to form inter metallic compounds along the sliding surface or grain boundary of the differential row. Precipitation hardening stainless steel 17-4PH is commonly used, while others include 17-7PH, PH15-7MO, AM-350, AM-355, etc.

(5) Post welding heat treatment of various stainless steels: After welding, the chromium contained in stainless steel will often diffuse and precipitate in the high temperature area (heat affected zone) and form chromium carbide by carbon bonding, resulting in local reduction of chromium content and failure to form a protective film. Corrosion such as perforation often occurs in these heat affected zones, which can remedy this situation. Operators often heat treat objects after welding, Its function can make the chromium element in other areas diffuse to the chromium deficient area to achieve protection.

Key words: stainless steel casting, precision casting, Shenzhen casting, India casting, Dongguan casting, carbon steel, precision casting, alloy steel, martensitic stainless steel, austenitic stainless steel, silica sol casting