Dissertation > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > Metal corrosion protection,metal surface treatment > Corrosion control and protection > Metal surface protection technology > Metal preservatives,corrosion inhibitors

Development of Biologic Corrosion Inhibitor and Its Mechanism Research

Author YangShangJun
Tutor TanShiYu
School Chongqing University
Course Physical and chemical
Keywords Hair Hydrolysate Biologic Corrosion Inhibitor Electrochemical Performance Inhibition Mechanism
CLC TG174.42
Type Master's thesis
Year 2006
Downloads 215
Quotes 3
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An important method of protection of metals against corrosion is by using inhibitors. To study the cost cheap, high efficiency, environmental benign corrosion inhibitor, have important practical value doubtless.According to the inhibition principle, with the hydrolyte of the life-form materials, such as the pineapple peels, orange husk, bamboo leaf and hair etc, contrasted to study these hydrolytes as acid picking inhibitors and their inhibiting properties to A3 steel in acid solution. When temperature under 60℃, adding 15%(v) in the 10% hydrochloric acid and 20% vitriol acid solution, the corrosion rate of the pineapple peels, orange husk, bamboo leaf and hair, respectively is: 35.42%,78.14%、65.81%,55.20% and 62.37%,79.52,76.15%,85.57%。The results showed that these hydrolytes all had some inhibition effect, but abundant usage, low inhibition effect, unless to append other inhibitors to improve inhibition effect.For the sake of declining cost and recycling waste resource, the research chose the liquid from hydrolyzing hair and the waste condensed liquid from the cystine workshop as corrosion inhibitors in acid picking. Through the initial experiment, the formulation was determined as: the cooperate inhibition of urotropine, potassium iodide and quaternary ammonium salt, restraining acid mist with quaternary ammonium salt, OP and surface active agent. The orthogonal experiments have been adopted to develop a WF inhibitor. The optimum formulation is as follows: the waste condensed liquid from the cystine workshop or the liquid from hydrolyzing hair 50ml, quaternary ammonium salt 15ml, urotropine 15g, potassium iodide 0.5g, surface active agent 2.0ml. The optimum concentration is 1.0%.When temperature downward 60℃,WF inhibitor has excellent corrosion mitigation for carbon steel in 20% H2SO4 solution.The corrosion rate, corrosion potential (Ecorr) and corrosion resistance (Rp) of the inhibitor, were investigated by weight-loss measurements and electrochemical experiments. Physical measuring and testing techniques had investigated the corrosion mitigation mechanism. Potentiodynamic polarization curves show that, WF can inhibit the reaction of anode when added into 20% H2SO4 solution. The anodic polarization curve in H2SO4 solution in the presence of WF is far different from it in the solution without WF, All the mention results proves that WF as the adsorption inhibitor can inhibit the anode reaction primarily. Impedance measurements indicate that within the experimental temperature the inhibitor ability of WF decreases, with the rise of the temperature. The corrosion inhibition efficiency of WF for carbon steel increases with concentration rising when its concentration is lower than 1.0%, and becomes almost constant when higher than 1.0%. Physical measuring and testing techniques indicate that, the inhibitor takes effect by means of forming physical absorption by electrostatic attraction.Through the usage of the enterprise continued half a year, the WF inhibitor used for 20% H2SO4 acid picking steel pipesφ25 50 about 0.5 kg/t, the acid mist is restrained commendably.

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