Corrosion Crystallization Mechanism Research Of 316L Stainless Steel Equipments Of Ammonium Sulfate Crystallization Devices

316L stainless steel is wildly used in today industry, which has good mechanical properties and anti-corrosion abilities. But the improper application of corrosion failure is also frequent, for example several kinds of corrosion in 316L stainless steel equipments of certain chemical ammonium sulfate crystallization devices.In the paper, the author mainly had based on the theory of failure diagnosis, analyzed the cause of failure according to the basic steps of failure analysis and TESTING and had researched the corrosion behavior of 316L stainless steel in different temperature, concentration and flow rate environmental conditions by using the methods of weight loss, electrochemical measurements, SEM and other technology research.The main results are as follows:In the Chemical ammonium sulfate crystallization equipments, tube was pitting corrosion, pump was erosion-corrosion and the inner wall of ammonium sulfate crystallizer was uniform corrosion; 316L stainless steel corrosion rate is mainly affected by temperature, corrosive media concentration as well as the velocity; Under certain conditions, the corrosion rate increases with the temperature and concentration increase and decreases as the increasing of flow rate; The simulating temperature range was 20-80℃, the flow range was 0-1.5m/s and the concentration range was 10,000 to 40,000 PPM; In the same conditions, the relations of 316L stainless steel corrosion rate are that chlorine, sulfur ion> chloride> sulfide ions; The SEM showed that there were lots of corrosion pits on the surface of sample in a long time corrosion conditions, and the higher temperature, the more obvious apparent.