stainless steel natural gas grill Accelerated estimation of corrosion rate in supercritical and ultra-supercritical water

by:Longzhao BBQ     2020-01-02
stainless steel natural gas grill Accelerated estimation of corrosion rate in supercritical and ultra-supercritical water
This study explores a method for determining the accelerated corrosion rate of candidate materials for advanced supercritical and supercritical materialsSupercritical waterHot reactor.Using AC impedance spectroscopy and AC frequency modulation techniques, SAE 316 stainless steel, Nitronic 50, Inconel 718 and Inconel 625 were evaluated in ultra-critical water at °c and ultra-high temperaturesUltra-critical water at 600 °cThese results were compared with the results of the weight study, which was carried out to determine the feasibility of using the electrochemical analysis in the supercritical and supercritical environmentsSupercritical waterFor the conditions of all tests, the results show that the corrosion rate during the electrolytic test has a tendency similar to long-time corrosionWeight results.Therefore, the mixed method described in this manuscript can reduce the test time from> 1000 Thanh ~ 10 h.Nuclear energy and coalThe ability of thermal power plants to use both SCW and SCWUltra-critical water (USCW ).The former is defined as water at operating temperatures and pressures above 37 °c and 22 °c.1 mpa, which is defined as water at operating temperatures and pressures above 590 °c and 25 mpa, respectively.The benefit of power plants designed to operate with SCW and USCW as heat transfer media is the improvement of Cano efficiency.Coal-With USCW, the efficiency of thermal power plants can reach about 50%, while the efficiency of reactors proposed by the nuclear industry using SCW can reach about 45%, which is the efficiency of traditional reactors.The properties of the SCW require additional evaluation of the structural materials before they are incorporated into the reactor design.An example of the complex nature of SCW is that this fluid acts as both a gas and a liquid.Therefore, SCW is described as a dense gas with a different corrosion behavior than liquid water.Due to the complexity of the environment and the system, studies conducted using SCW only include observations before and after exposure.Because there is no on-site measurement under typical operating conditions, for a long timeLong-term exposure test, I.e.It takes several months to several years to estimate the corrosion rate.The electrochemical analysis performed by other authors has demonstrated the feasibility of accelerated corrosion testing, however, to allow such testing, the conditions they use are significantly different from the actual operating conditions of the power plant.Botella et al.It is proved that the dynamic potential polarization scan can be used to evaluate the static 80-ML autoclave containing SCW.Various additives were used to improve the conductivity, including potassium chloride, HCl, HSO and KSO, while the polarization curves were obtained.In addition, this method is limited to a maximum temperature of 400 °c, which does not allow the testing of materials under the conditions of use proposed for a supercritical water reactor.Research conducted by Baker and others.The results show that the results obtained by DC method are inconsistent, and the results obtained by AC method are more reliable.When the electrochemical frequency modulation (EFM) and electrical impedance spectroscopy (EIS) were used, the results were more consistent with the values reported in the literature.Tested with SAE stainless steel 316 (SS316), Nitronic 50 (N50), Inconel 625 (I625) and Inconel 718 (I718,Temperature power plant.The aim of this study was to establish a method to evaluate the corrosion rate of pure SCW and to reduce the test time to less than 24 hours.
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