Corrosion Mechanism Research And Corrosion Monitoring Management System Development Of Chemical Equipments

Some mediums in the process of chemical production have the characteristics of low pHand highactive anion concentrations.The corrosion environment is severe and some corrosion failuresof equipments occur occasionally.The paper mainly research on the corrosion of chemical production equipment of Q345R,10steel,304L and316L. The main influence effects of material corrosion in the mediumare determined by ion chromatograph; The influence rules of ion concentration, temperature and pH on the corrosion rate of materials are studied by means of immersion test and electrochemical method.The composition of corrosion products and microscopic characteristics are further analysedby spectrometer and scanning electron microscopy. The corrosion types ofmaterialsare analysed and the corrosion mechanisms are discussed. At last, a corrosion monitoring and management system of chemical equipments is developed.The research results show that the corrosion factors of Q345R in an acidic water includ Cl-concentration, temperature, pH, formic acid and acetic acid ions.The corrosion mechanism is related to pH value. The corrosion rate is influenced by temperature, Cl-concentration and pH.The corrosion rate is slow and not easy to produce under-deposit corrosion when pH is at the range of3.5to4.5.The corrosion rate of10steel in an oil phase is related to temperature. The corrosion rate of10steel increases with temperature from30℃to50℃, while it doesn’t occur corrosion at10℃.316Lhas excellent corrosion resistance ability in PTSAand temperature has little effection on the corrosion rate of316L.The corrosion resistance abilityof uniform corrosion resistance, small hole corrosion and stress corrosion cracking of304L in a water phase is excellent. Temperature has a little effects on the corrosion rate. The corrosion rate increases with the increasement of pH value.The corrosion monitoring and management system can monitor the corrosion condition of chemical equipments, and it can analysis and alarm the corrosion stateand predict the residual service life of chemical equipments.