铝合金实验室加速腐蚀及等效加速关系确定方法OA

To deal with the atmospheric corrosion failure of aviation aluminum alloy materials,a"double bridge connection"method for rapid determination of aluminum alloy accelerated corrosion environmental spectrum and its equivalent acceleration relationship with the actual atmosphere was proposed.The method takes the corrosion electricity and corrosion weight loss of materials as equivalent parameters,and mainly includes three steps:preparing the laboratory accelerated environment spectrum based on the method of"weighted concentration of environmental factors",obtaining the long-term cumulative corrosion electricity in the actual atmospheric environment based on the"electricity(current)equivalent bridge",and determining the equivalent acceleration relationship based on the"weight loss equivalent bridge".The equivalent acceleration relationship is obtained through the calculation of atmospheric environment monitoring data,laboratory corrosion weight loss test and short-term atmospheric exposure test results without long-term exposure test pieces.Firstly,according to the proposed method for determining the equivalent acceleration relationship,the atmospheric environment monitoring data of a tropical area for 10 years are collected and sorted out,and the climatic environment spectrum and chemical environment spectrum of the atmospheric environment in this area are compiled.By analyzing the content and products of corrosive media in the atmosphere and the method of weighted concentration,and combined with the test method of periodic infiltration,a laboratory accelerated corrosion environment spectrum is compiled.Secondly,the atmospheric corrosion monitoring technology(ACM)and electrochemical workstation are used to measure and calculate the corrosion current and conversion coefficient of ZL114A aluminum alloy in different temperature and humidity atmospheric environments and different concentrations and types of acid solutions.Combined with the short-term(85 days)measurement results of environmental temperature and humidity,corrosion current and corrosion electricity,the cumulative corrosion electricity of ZL114A aluminum alloy exposed to the island atmosphere for 10 years is 3050339.15c according to the"electricity(current)equivalent bridge".Next,a laboratory corrosion weight loss test is carried out to obtain the average corrosion weight loss rate of ZL114A aluminum alloy per unit area under the action of accelerated corrosion environment spectrum in the laboratory.Then,according to the corrosion weight loss electricity conversion relationship of the aluminum alloy in the field environment,the corrosion weight loss of the aluminum alloy exposed in the field atmospheric environment for 10 years is calculated to be 57.96 g.Afterwards,according to the"weight loss equivalent bridge",the equivalent acceleration relationship between the three types of laboratory accelerated corrosion environment spectrum and the actual atmospheric environment is calculated to be 74 h/a.Finally,in order to verify the feasibility of the proposed method for determining the equivalent acceleration relationship,the surface damage morphology,pitting pit size,fatigue life and fracture morphology of ZL114A aluminum alloy are measured by SEM,CT scanning and other means after 6 months of atmospheric exposure,1 year of atmospheric exposure and 72 hours of laboratory accelerated corrosion environment spectrum.The results show that the corrosion damage modes of atmospheric exposure specimens and accelerated corrosion specimens are the same,and the damage severity is consistent with the equivalent acceleration relationship.