Effects of chromium on the corrosion and electrochemical behaviors of ultra high strength steels

Jin-yan Zhong1),Min Sun2),Da-bo Liu3),Xiao-gang Li2),and Tian-qi Liu3) 1) School of Chemistry and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China 2) School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China 3) Beijing Institute of Aeronautical Materials,Beijing 100095,China

摘 要：The effects of chromium on the corrosion and the electrochemical behaviors of ultra high strength steels were studied by the salt spray test and electrochemical methods.The results show that ultra high strength steels remain martensite structures and have anodic dissolution characteristic with an increase of chromium content.There is no typical passive region on the polarization curves of an ultra high strength stainless steel,AerMet 100 steel,and 300M steel.However,chromium improves the corrosion resistance of the stainless steel remarkably.It has the slowest corrosion rate in the salt spray test,one order of magnitude less than that of AerMet 100 and 300M steels.With the increase of chromium content,the polarization resistance becomes larger,the corrosion potential shifts towards the positive direction with a value of 545 mV,and the corrosion current density decreases in electrochemical measures in 3.5wt% NaCl solutions.Because of the higher content of chromium,the ultra high strength stainless steel has a better corrosion resistance than AerMet 100 and 300M steels.

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