Precision cast steelThe secret of casting vacuum heat treatment

(1) Martensitic stainless steel: The cubic (BCC) of this solid stainless steel structure can be magnetized. The field temperature is from Oswald quenching and the corrosion resistance is the best, but the material is hard and brittle, and then tempering can increase the ductility. However, the corrosion resistance will be reduced, especially when tempering between 450 degrees Celsius and 650 degrees Celsius, a network of chromium consumption is formed in the lattice gap where carbon atoms diffuse, and the chromium carbide and chromium precipitation are reduced, and the protective film cannot be formed. , And the loss of corrosion resistance, so special attention is required. The following is the heat treatment of various martensitic stainless steel materials.

(1) At 650-750 C. 403410416se temperature

(b) 650-730 at a temperature of 414°C

The temperature of (C) 431 is in 6 (D) 440-a, 440-b, 440-c, and the temperature is 420 680-750.

(2) Ferritic stainless steel,Lost wax castingStainless steel body-centered cubic structure (BCC) can be used as a commonly used magnet in the automobile industry and chemical industry. The strength will not change due to heat treatment, but it can increase the strength of the cold working method.

(3) Austenitic stainless steel, stainless steel face-centered cubic structure (FCC) has no effect on the magnet. For example, the front of the material is easy to process. The processed material can eliminate residual stress and can be applied to different heat treatments.

(4) Precipitation-hardening stainless steel: low-temperature stainless steel after high-temperature quenching, containing aluminum or copper materials, forming compound precipitates (inter-compounds) along the sliding surface or differential arrangement of the grain boundary, which can improve its strength or hardness. Commonly used precipitation hardening stainless steel 17-4PH, other 17-7PH, PH15-7Mo, am-350, am-355, etc.

(5)Guangdong alloy steel castingHeat treatment after welding of all kinds of stainless steel: chromium-containing stainless steel, welding, has a tendency to spread in the high temperature zone (heat-affected zone), precipitation and chromium carbide carbon synthesis, causing the local chromium composition to decrease, unable to form a protective film, and perforation corrosion often occurs in this area. The influence of heat in the area makes up for the usual post-weld heat treatment in the industry, and the effect can make the areas lacking in areas such as chromium and chromium diffusion to achieve a protective effect.