Corrosive liquid for detecting corrosion resistance of high-nitrogen stainless steel passive film

The invention relates to a corrosive liquid for detecting the corrosion resistance of a high-nitrogen stainless steel passive film, and belongs to the technical field of metal surface treatment. The corrosion liquid disclosed by the invention is composed of CuSO4, NaCl, CH3COOH and water, and the pH value of the corrosion liquid is 3.0-4.0; the concentration of CuSO4 in the corrosive liquid is 40-60 g/L, and the concentration of NaCl in the corrosive liquid is 45-55 g/L. The sodium chloride in the corrosive liquid provides corrosive chloride ions, and the acetic acid can maintain the pH value at 3.0-4.0 to generate a stable weakly acidic corrosive environment and also can accelerate the corrosion rate of the chloride ions in the sodium chloride; the copper sulfate can chemically react with free iron appearing on the surface of the high-nitrogen stainless steel, so that the color of the solution is changed or black corrosion spots appear, and visual inspection is facilitated; the synergistic effect of the thre