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Dongguan Precision Casting Regarding the Heat Treatment Technology of Stainless Steel
- 2020-02-13-

Stainless steel is often divided into: austenitic steel, ferritic steel, ferritic steel, ferritic-metallographic structure (duplex) stainless steel and settled hard bottomed stainless steel. In addition, it can be divided into chromium stainless steel, chromium nickel stainless steel, chromium manganese nitrogen stainless steel and so on. Special stainless steel for pressure vessels is also used. Dongguan Precision Casting has made the following heat treatment technical precautions for stainless steel:

(1) Matian scattered iron stainless steel: The body-centered cubic structure (BCC) of this type of stainless steel can be attracted by the magnet and obtained by quenching it from the Osten temperature. At this time, the corrosion resistance is the best, but the material Hardness is brittle, followed by various quenching can improve plasticity, but the corrosion resistance will be reduced, especially the intermediate quenching between 450°C and 650°C, will cause the carbon atoms in the crystal lattice voids to diffuse and dissolve and chromium produces a network structure of carbonization. Chromium causes the consumption of chromium in neighboring areas to reduce the chromium composition, and cannot produce protective film, and lacks corrosion resistance, so attention should be paid to it.

(2) Ferrous iron stainless steel: This type of stainless steel body-centered cubic meter structure (BCC) can attract magnets, and is generally used in the automobile industry or chemical industry. The strength is not easy to change due to heat treatment, but it can be cold-worked to increase the strength .

(3) Austian ferrous stainless steel: This type of stainless steel body core structure (FCC) fails to the magnet. For example, as mentioned above, this type of raw material is easy to produce and process, so after it is produced and processed, the residual stress of the raw material can be removed. The same heat treatment.

(4) Dissolving hard-bottomed stainless steel: This type of Dongguan precision cast stainless steel is heat-treated at ultra-low temperature after high-temperature heat treatment. Chemical substances (inter -metalliccompounds) and can improve its compressive strength or strength. Commonly used dissolving hard-bottomed stainless steel 17-4PH, there are also 17-7PH, PH15-7MO, AM-350, AM-355, etc.

(5) Heat treatment after electric welding of various stainless steels: After electric welding, the chromium element contained in stainless steel will diffuse and dissolve and fuse with carbon to form chromium carbide in high temperature areas (heat hazard areas), resulting in part of the chromium content being reduced. , No protective film can be produced, and erosion such as holes are often produced in such thermally hazardous areas, which can save such situations. Practitioners often heat the objects after electric welding is completed, and its effect can make other areas The chromium element diffuses to this chromium-deficient area to achieve the protective effect.