Research On Corrosion Behaviors Of Typical Materials For High-speed Rail Vehicles In Atmospheric Environment

The corrosion behaviors of stainless steel welding materials,copper tin plating materials and polymer rubber materials exposed in the typical atmospheric environment were studied by using a series of characterization means,such as ultra depth microscope,SEM/EDS,Raman,FTIR,X ray diffractometer,Tafel polarization curve,EIS and so on.The main research results of this paper are as follows:1.Site ranking of maximum pitting depth for stainless steel welding material samples:Wanning,Qingdao,Beijing,Guangzhou,Jiangjin,Wuhan,Shenyang,Mohe.After two years of exposure to the WuHan Railway Station and WanNing Railway Station.The stability of the passivation film on the 301LN surface is the best,and the corrosion resistance is also the best;The passivation film on the surface of the weld zone has the worst stability,pitting corrosion is more likely to occur,and the corrosion resistance is the worst;The surface corrosion products of various regions are mainly composed of?-Fe₂O₃,?-Fe₂O,.?-FeOOH,?-FeOOH,?-FeOOH and Fe₃O₄.Electrochemical analysis show that the surface of the sample after Wanning Station test is seriously corroded and the self-corrosion current density is at the level of 10^-5A?cm^-2.The analysis results of the grey correlation degree show that sunshine hours,average temperature,Cl^-,dust fall dominate te development of the maximum pitting depth of stainless steel welding materials.The correlation between the NH₃ deposition rate and the maximum pitting depth is minimal.the correlation degree of sunshine,average temperature,and Cl^-factor showes an increasing trend.2.Obvious corrosion occurred on the surface of tin plated copper samples.The corrosion rate reached 7.320?m/a after two years of exposure to WanNing Railway Station.Corrosion dynamics show that the corrosion rate corresponds to siteranking:Wanning,Qingdao,Mohe,Guangzhou,Shenyang,Jiangjin,Beijing,Wuhan,The corrosion products of the samples are mainly consisted of SnO and SnO_2.Grey correlation analysis indicate that Cl^-,average temperature,rainfall and sunshine hours as the main factors affect the rate of corrosion for copper tin,SO₂ and NH₃ on the corrosion rate of copper tin have certain effect but not obviously.Electrochemical analysis show that the corrosion resistance corresponds to the site order:Beijing Station,Jiangjin Station,Guangzhou Station,Qingdao Station,Wanning Station;The self-corrosion current density of the rust sample of Wanning Station is the largest,reached 4.012×10^-5A?cm^-2.3.The roughness of the rubber sample after aging increases and it is covered with a large number of network-like cracks.;Tensile strength and elongation at break decreased and hardness increased.Infrared analysis show that there are fattyacids on the surface of the samples after aging.Gray correlation analysis shows that the main meteorological factors affecting the aging performance of rubber parts are sorted,with Annual average Humidity,Sunshine duration,Total annual Irradiation,Annual average Temperature,Annual Rainfall of which annual average humidity has the largest impaction,and annual rainfall has the smallest impaction;In the past two years,the correlation between environmental factors and aging performance has shown a downward trendency.