氟蛋白泡沫灭火剂中核心组分对铝合金的腐蚀影响研究

Study on the impact of core components in Fluoroprotein Foam fire extinguishing agents on the corrosion of aluminum alloys

为了探究氟蛋白泡沫(Fluoroprotein Foam,FP)灭火剂中核心组分对铝合金腐蚀行为的影响,利用浸泡失重、动电位极化(Potentiodynamic Polarization,PDP)和电化学阻抗谱(Electrochemical Impedance Spectroscopy,EIS)等方法开展了试验研究。结果表明,FP组分中水解蛋白、稳定剂、助溶剂和抗冻剂起到促进铝合金腐蚀的作用,而两种表面活性剂产生缓蚀作用,其中,作为稳定剂的FeSO_(4)腐蚀作用最强,氟碳表面活性剂的缓蚀效果最明显,通过PDP和EIS得到7%FeSO_(4)的腐蚀率分别为29.19%和32.14%,7%氟碳表面活性剂的缓蚀率分别为25.22%和18.21%。此外,铝合金的Nyquist图均呈现出扁平半圆弧特征,通过拟合后得到的电化学参数进一步证实了浸泡失重试验的结论,FP各组分的腐蚀性由强到弱依次为FeSO_(4)、醋酸钴、水解蛋白、乙二醇、尿素、SDS、OBS。

To investigate the effects of the core components in Fluoroprotein Foam(FP)fire extinguishing agents on the corrosion behavior of aluminum alloys,experiments were conducted using various methods,including weight loss after immersion,Potentiodynamic Polarization(PDP),and Electrochemical Impedance Spectroscopy(EIS).Optical microscopy was also employed to examine the corrosion characteristics of aluminum alloys at different mass fractions of FP components.The results indicate that:(1)In the immersion weight loss test,five components in FP—hydrolyzed protein,FeSO_(4),cobalt acetate,urea,and ethylene glycol—exhibited a promoting effect on the corrosion of aluminum alloys.In contrast,the two surfactants demonstrated a corrosion inhibition effect,with OBS showing superior corrosion resistance compared to the other surfactant.By comparing the corrosion weight loss rates,the corrosiveness of FP components to aluminum alloys can be ranked from strongest to weakest as follows:FeSO_(4),cobalt acetate,hydrolyzed protein,ethylene glycol,urea,SDS,and OBS.(2)Electrochemical results indicate that components in FP,such as hydrolyzed protein,stabilizers,solvents,and antifreeze,promote the corrosion of aluminum alloys by facilitating both the cathodic hydrogen evolution reaction and the anodic metal dissolution reaction.In contrast,the two surfactants inhibit the anodic metal dissolution reaction by obstructing the charge transfer process through adsorption,thereby exerting a corrosion inhibition effect on aluminum alloys.(3)As a stabilizer,FeSO_(4)exhibits the strongest corrosive effect,while the fluorocarbon surfactant demonstrates the most pronounced corrosion inhibition effect.The corrosion rates measured from PDP and EIS for 7%FeSO_(4)are 29.19%and 32.14%,respectively,while the corrosion inhibition rates for 7%fluorocarbon surfactant are 25.12%and 18.21%,respectively.Additionally,the Nyquist plots for aluminum alloys exhibit a flat semi-circular arc characteristic.The corrosion rates for each component obtained through fitting further validate the conclusions drawn from the immersion weight loss test.(4)The corrosive effect of FP on aluminum alloys is primarily attributed to the stabilizer;therefore,it is recommended to either reduce the amount of heavy metal strong acid salts or to develop a set of synergistic corrosion inhibitors that do not compromise the stability of FP,in order to mitigate its corrosive effects on metal materials.