Corrosion resistance test of nitriding layer in well type nitriding furnace

Parts after nitriding furnace need to be tested, and corrosion resistance is also an important factor affecting quality testing. The heat treatment multi-purpose furnace has a powerful electrical control system Siemens prc, which should be easy to operate. Generally, it has a front chamber and a back chamber, which are also heating chambers. The sealing requirements are good, such as carburizing and nitriding. Multi purpose furnace is a thermal equipment with continuous production of multi-layer furnace bed, also known as rake furnace or multi chamber furnace. It is used for burning municipal waste, baking nonferrous metal mineral powder, light burning magnesium hydroxide filter cake and natural magnesite mineral powder, etc. The box type multipurpose furnace is mainly used for gas carburizing direct quenching of workpieces, gas carburizing quenching with intermediate cooling, gas carburizing shielding gas cooling, re carburizing, carbonitriding and quenching, nitrocarburizing (soft nitriding), isothermal quenching, bright normalizing, bright annealing, brazing, sintering. Then how to check the corrosion resistance of parts after nitriding furnace? The following points: For nitrided parts with corrosion resistance requirements, the thickness and corrosion resistance of the white light layer (phase) should be tested. As the corrosion resistance is related to the thickness and density of the white bright layer, according to GB/T 11354, the white bright layer on the surface of typical nitriding samples in the same furnace can be observed under the 500x metallographic microscope. The thicker, whiter and denser the white bright layer, the better the corrosion resistance. The corrosion resistance test of nitrided sample can be conducted by immersing it in 6 ー 10% copper sulfate solution for 1 ー 2 minutes to check whether there is copper deposit on the sample surface. If there is no copper deposit, it is qualified. Parts or samples can also be soaked in 10 grams of red blood salt and 50 grams of sodium chloride in 1 liter of distilled water solution for 1 to 2 minutes. The inspected parts must be washed with water immediately. When checking the corrosion resistance of nitriding furnace parts, special attention should be paid to the corrosion resistance of internal parts of grooves and sharp corners, which are often weak parts during nitriding