The parts after the well nitriding furnace need to be tested, and the corrosion resistance is also an important factor affecting the quality testing. The multi-purpose furnace for heat treatment has a powerful electrical control system Siemens PRC, which should be easy to operate. Generally, there will be a front chamber, a rear chamber, that is, a heating chamber, with good sealing requirements, carburizing and nitriding, etc. Multipurpose furnace is a continuous production thermal equipment with multi-layer hearth, also known as rake furnace or multi chamber furnace. It is used for burning municipal waste, roasting nonferrous metal ore powder, lightly burning magnesium hydroxide filter cake and natural magnesite ore powder. The box type multipurpose furnace is mainly used for gas carburizing direct quenching of workpieces, gas carburizing quenching with intermediate cooling, gas carburizing protective gas cooling, re carburizing, carbonitriding and quenching, nitrocarburizing (soft nitriding), isothermal quenching, bright normalizing, bright annealing, brazing and 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 white light layer (phase) shall be tested
since the corrosion resistance is related to the thickness and density of the white bright layer, the white bright layer on the surface of typical nitrided samples in the same furnace can be observed under a 500X metallographic microscope according to GB / T 11354, The thicker, whiter and denser the white bright layer, the better its corrosion resistance. The corrosion resistance test of nitriding sample can be soaked in 6 ± 10% copper sulfate solution for 1 ± 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 g of red blood salt and 50 g of sodium chloride in 1 l 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 shall be paid to the corrosion resistance of internal parts of grooves and sharp corners, which are often weak parts in the nitriding process
