Stainless Steel Solution Heat Treatment

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Carbon has a large effect on the solubility and temperature of austenitic stainless steel. When austenitic stainless steel is exposed to a temperature range of 400 ° C to 850 ° C, high chromium carbides are precipitated. When the chromium content falls below the limit of corrosion resistance, the grain boundary is depleted in chromium and intergranular corrosion occurs. It can become a powder when it is severe. Therefore, the austenitic stainless steel having a tendency to intergranular corrosion should be subjected to solution heat treatment or stabilization treatment.

Solution heat treatment: The austenitic stainless steel is heated to about 1100 ° C, so that the carbide phase is completely or substantially dissolved, the carbon is solid-dissolved in austenite, and then rapidly cooled to room temperature to make the carbon supersaturated. This heat treatment method is a solution heat treatment.

The rapid cooling in solution heat treatment seems to be quenching like ordinary steel, but the ‘quenching’ at this time is different from the quenching of ordinary steel, the former is softening treatment, and the latter is hardening. The latter used different heating temperatures for different hardnesses, but did not reach 1100 °C.

quenching of stainless steel
The quenching of steel is to heat the steel to a temperature above the critical temperature Ac3 or Ac1, hold it for a period of time, make it austenitized in whole or in part, and then rapidly cool to below Ms with a cooling rate greater than the critical cooling rate. The heat treatment process of the transformation.

The solution treatment of materials such as aluminum alloys, copper alloys, titanium alloys, tempered glass, or the heat treatment process with a rapid cooling process is also referred to as quenching.

The purpose of quenching is to transform the supercooled austenite into martensite or bainite, obtain martensite or bainite structure, and then mix with tempering at different temperatures to greatly improve the strength, hardness and wear resistance of the steel. Sex, fatigue strength and toughness to meet the different requirements of various mechanical parts and tools. Special physical and chemical properties such as ferromagnetism and corrosion resistance of certain special steels can also be met by quenching.

The fundamental reason why quenching can strengthen steel is phase transformation, that is, austenite structure becomes martensite structure through phase transformation.

High pressure gas quenching vacuum furnace,It is mainly applied for vacuum quenching,annealing of high-pressure tool steels such as high-alloy tool steels, high-speed steels, and stainless steels, and high-temperature alloy magnetic materials. It can also be used for vacuum sintering of powder metallurgy, stainless steel, and brazing of copper.