Influnce Of Technological Parameter On Corrosion For 2205DSS And TA2 In Brine And Establishment Of Mathematical Model

Some salt making indurstry group carried on refined brine technology by two-alkali method, however, the brine components and technology parameters all changed, and it made the main equipments serious localized corrosion. The pilot study was analysed against the actual serious corrosion in this paper.The influence on the resistance to corrosion behavior was studied for 2205DSS and TA2 in brine under the different CO32- concentration and pH value and the different temperature and flow velocity of brine by electrochemical method and the weight loss in coupon tests in this paper. Under this experience condition, the results showed that the influence of two-alkali method on the resistance to corrosion was very largely for 2205DSS and TA2 in brine solution. The ability of resistance to corrosion enhanced slightly first, but then descended obviously with increasing the CO32- concentration and pH value in brine solution largely for 2205DSS. The ability of resistance to corrosion enhanced obviously for the metal system decreased gradually with increasing the CO32- concentration and pH value in brine solution for TA2. The ability of resistance to corrosion enhanced first, but then descended obviously with increasing the flow velocity of brine largely, and descended with rising up temperature rapidly for 2205DSS and TA2 in brine solution.The best technology parameters were constituted when two-alkali method was used according to the actual salt making technology in this paper. The results showed that CO32- concentration was controlled at 1.0g/L in brine and in the range of 8.3 to 8.7 for pH value and in the range of 2.0 to 3.0m/s for brine velocity. The ability of the resistance to corrosion was the strongest in the area relatively. Electrode process was discussed for 2205DSS and TA2 in brine by electrochemical impedance spectra in this paper. The results showed that the electrode reaction was irreversible and controlled by both activation polarization and diffuseness for 2205DSS and TA2 in brine medium. The charge transfer parameter value of TA2 was 0.35 and the diffusion coefficient value of O2 was 5.34×10-7cm2/s in brine solution.The soft-measurement method was applied on the evaluation of the salt brine corrosion first. According to the relationship between the enviremental parameters and the corrosion rates of 2205DSS and TA2, the corrosion mathematical models were simulated for 2205DSS and TA2 in brine by soft-measurement method in this paper. In the range of 20~120℃temperature, the results showed that the corrosion simulation models for 2205 DSS and TA2 in rest brine were: and in the flow brine were:...