What is the reason why 304 stainless steel strip needs sensitization treatment? Sensitization treatment is applied to 304 stainless steel strip. The so-called sensitization treatment generally refers to austenitic stainless steel that has been subject to solid solution treatment. After heating at 500~850 ℃, chromium precipitates from the solid solution to form chromium carbide, which causes the grain boundary corrosion sensitivity of austenitic stainless steel. This is sensitization treatment. It is used to measure the grain boundary corrosion tendency of austenitic stainless steel, which is one of the detection methods. Photosensitive treatment actually does not belong to the heat treatment method that should be adopted in the production and manufacture of 303 stainless steel bar or its products. This method is a test method to test the intergranular corrosion resistance of 304 stainless steel strip. Photosensitive treatment is essentially a method to make austenitic stainless steel more sensitive to intergranular corrosion. The sensitization treatment can precipitate a large number of alloy carbides such as austenitic stainless steel (FeCr) 23c6 along the grain boundary, resulting in intergranular corrosion in the intergranular corrosion medium, so as to achieve rapid detection of the intergranular corrosion resistance of austenitic stainless steel. The domestic test method for intergranular corrosion resistance of 304 stainless steel generally stipulates that the sensitization treatment system for austenitic stainless steel containing C ≤ 0.03% or stable elements is: heating to 650 ℃, heat insulation 2H air cooling for forged and rolled test pieces, and heat insulation 2H air cooling for cast test pieces. In some special applications, in order to evaluate the intergranular corrosion resistance of materials more strictly, the sensitization system of 316 stainless steel bars is more strictly specified in some standards. Different sensitization systems are adopted according to the temperature of the workpiece used in the future, the carbon content of the material and whether it contains aluminum. Others control the rising and falling speed of sensitization treatment. Therefore, when judging the tendency of intergranular corrosion of 304 stainless steel strip, the sensitization system should be used.