Stainless steel heat treatment technology for foundries

Date:05-07-2018

(1) Ma Tian loose iron Stainless Steel Casting Parts : This type of stainless steel body-centered cubic structure (BCC) can attract magnets and cool them from Aostian temperature. This has the best corrosion resistance, but the material is hard and brittle. Then tempering can increase the ductility, but the corrosion resistance will be reduced, especially when tempering between 450 degrees Celsius and 650 degrees Celsius will cause the carbon atoms in the crystal lattice gap to diffuse and form a chromium-like chromium carbide. The consumption of chromium in the adjacent area causes the chromium component to decrease, the protective film cannot be formed, and the corrosion resistance is lost, so special care is required.

(2) Fertilizer iron stainless steel: This stainless steel body-centered cubic structure (BCC) can attract magnets and is usually used in the automotive industry or chemical industry. The strength is not changed by heat treatment, but it can be increased by cold working.

(3) Austin ferrous stainless steel: This stainless steel face-centered cubic structure (FCC) does not work on magnets. As discussed above, such materials are easy to process, so they can be used to eliminate residual stresses after processing. Heat treatment.

(4) Precipitation hardening type stainless steel: This type of stainless steel is heat-treated at a low temperature after high-temperature quenching, and may be caused by aluminum or copper element precipitated in the material along the slip surface or inter-metallic compounds of the difference row. Increase its strength or hardness. Commonly used precipitation hardened stainless steel 17-4 PH, others still have 17-7 PH, PH15-7MO, AM-350, AM-355 and so on.

(5) Post-weld heat treatment of all kinds of stainless steel: After the welding, the chromium element contained in the stainless steel will be diffused and precipitated in the high temperature region (heat-affected zone) to form chromium carbide, which will reduce the local chromium content. A protective film is formed, and corrosion such as perforation often occurs in these heat-affected zones. This situation can be remedied. The manufacturer often heats the object after welding, and the effect is to diffuse the chromium element in other regions to the chromium-deficient region. To achieve protection.