Soil Acid Medium Stainless Steel High-temperature Corrosion Inhibitor Development And Research

This paper studied the corrosion velocity and corrosion inhibition efficiency of 304~# stainless steel in 10% mud acid (7%HCl+3%HF) with a few of compounds by weight-loss method, then two kinds of compounds with good corrosion inhibition effect have been got in mud acid solution, including alkynol and cationic surfactant.In these compounds benzalkonium chloride , propiolic alcohol and butynediol were selected as research object. Their corrosion inhibition action of 304~# stainless steel in 10% mud acid was studied with different temperatures in mud acid solution by adsorption theory and electrochemical polarization-curve method, the mechanism of corrosion inhibition action was analyzed. The result shows that the single molecule layer of benzalkonium chloride, propiolic alcohol adsorbed on the surface of the 304~# stainless steel and followed Langmuir isothermal equation. The nonuniform molecule layer of The butynediol adsorbed on the surface of the 304~# stainless steel and followed Frumkin isothermal equation.The adsorption procedure was endothermic reaction, the adsorption ability and corrosion inhibition efficiency increased when temperature increased. They are all mixed type inhibitor. The corrosion current was decreased by them in different degree.These compounds used respectively have low corrosion inhibition efficiency in high temperature and price costliness, then can't meet practical require. So a composite corrosion inhibitor with excellent corrosion inhibition efficiency and costly was composed, corrosion inhibition action of this composite corrosion inhibitor has been evaluated by using weight-loss method, electrochemical polarization-curve method and scanning electron microscopy techniques.The results shows this composite corrosion inhibitor possess excellent corrosion inhibition of anti-temperature, anti-acidity, anti-time and anti-nonuniform corrosion. When temperature was 90℃, the concentration of mud acid solution (7%HCl+3%HF) was 20%, the reaction time was 20 hours and the velocity of flow was 0.4 m/s, the corrosion velocity of steel...