【摘要】：鋁是生產(chǎn)生活中常用的金屬之一,具有硬度大,機(jī)械強(qiáng)度好,易塑性等優(yōu)良性能,常用于制造罐體、反應(yīng)釜以及其他部件。鋁部件在使用過程中,內(nèi)壁會(huì)因?yàn)椴煌脑虍a(chǎn)生積垢,積垢易導(dǎo)致設(shè)備工作效率降低及安全系數(shù)下降等危害。采用鹽酸、硫酸、氫氟酸等對鋁部件進(jìn)行酸洗可清除積垢。酸洗液除垢的同時(shí)會(huì)使鋁發(fā)生腐蝕,而添加緩蝕劑可有效抑制酸洗中對鋁的腐蝕。土酸兼具鹽酸和氫氟酸的優(yōu)點(diǎn),但土酸中鋁緩蝕劑的研究較少,本文對5%土酸中鋁的緩蝕劑進(jìn)行研究。首先通過失重法,測試出添加不同試劑時(shí)5%土酸中鋁的腐蝕速率,并計(jì)算各試劑的緩蝕率。選出對5%土酸中的鋁具有較好緩蝕效果的三種試劑:三聚磷酸鈉(STP)、溴代十六烷基吡啶(CPB)和糠醛,并求算出對這三種試劑在鋁表面的吸附熱力學(xué)數(shù)據(jù)。三種試劑最佳用量分別為1g·dm-3、1g·dm-3、4g·dm-3;三者在鋁表面均符合Langmuir吸附,吸附是放熱過程,隨溫度升高,熵值減小,自由能減小,分子吸附能力減弱,緩蝕效率降低。動(dòng)電位極化曲線研究結(jié)果表明,添加三種試劑時(shí),鋁的腐蝕電位均小幅負(fù)移,陽極電流密度和陰極電流密度均降低,三者均為混合型緩蝕劑。將緩蝕效果較好的單組份試劑兩兩復(fù)配,得到五組具有協(xié)同作用的試劑:STP與糠醛、STP與CPB、STP與苯甲醛、STP與肉桂醛、苯甲醛與1227。利用失重法研究五組試劑的最佳協(xié)同效果配比,結(jié)果為0.14:0.06、0.12:0.08、0.10:0.10、0.16:0.04、0.16:0.04。動(dòng)電位極化曲線研究表明五組協(xié)同型緩蝕劑均為混合型緩蝕劑。雖然協(xié)同型緩蝕劑效果優(yōu)于單組份緩蝕劑,但是依然沒有達(dá)到最佳的緩蝕效果。將多種試劑進(jìn)行復(fù)配,研制出由一種無機(jī)鹽、一種含釩配合物及一種有機(jī)物組成的低毒的復(fù)合緩蝕劑J-HM。J-HM各成分間最佳配比為:無機(jī)鹽0.8g·dm-3、有機(jī)物1.2 g·dm-3、含釩配合物1.0 g·dm-3。通過失重法和動(dòng)電位極化曲線法考察J-HM對5%土酸中鋁的緩蝕性能。結(jié)果表明:加入J-HM后,鋁的腐蝕速率最低為0.83 g·m-2·h-1;J-HM緩蝕率最高可達(dá)到99.03%;J-HM最佳使用濃度為2 g·dm-3。土酸濃度小于6%,20 h之內(nèi),使用溫度在50℃以內(nèi)時(shí)緩蝕效果優(yōu)良。動(dòng)電位極化曲線測試結(jié)果表明J-HM為混合型緩蝕劑。綜上所述,J-HM是5%土酸中鋁的環(huán)境友好型高效復(fù)合緩蝕劑。
[Abstract]:Aluminum is one of the commonly used metals in production and life. It has many excellent properties, such as high hardness, good mechanical strength, easy plasticity, etc. It is often used in the manufacture of tank, reactor and other parts. In the process of using aluminum components, the inner wall will cause fouling due to different reasons, which will lead to the decrease of working efficiency and safety factor of the equipment. Using hydrochloric acid, sulfuric acid, hydrofluoric acid to pickle aluminum parts can remove dirt. The addition of corrosion inhibitor can effectively inhibit the corrosion of aluminum in pickling. Soil acid has the advantages of hydrochloric acid and hydrofluoric acid, but there are few studies on aluminum corrosion inhibitor in earic acid. In this paper, the corrosion inhibitor of aluminum in 5% earic acid is studied. Firstly, the corrosion rate of aluminum in 5% earic acid with different reagents was measured by weightlessness method, and the corrosion inhibition rate of each reagent was calculated. Three reagents, sodium tripolyphosphate (STP), hexadecylpyridine (CPB) and furfural (furfural), which have better corrosion inhibition effect on aluminum in 5% earic acid, were selected, and the adsorption thermodynamic data of the three reagents on aluminum surface were calculated. The optimum dosage of the three reagents is 1 g dm-3,1g dm-3,4g dm-3;. The adsorption is an exothermic process, and with the increase of temperature, the entropy value decreases, the free energy decreases, the molecular adsorption capacity weakens and the corrosion inhibition efficiency decreases. The results of potentiodynamic polarization curves showed that the corrosion potential of aluminum decreased slightly and the anode current density and cathode current density decreased when the three reagents were added. All of them were mixed corrosion inhibitors. Five synergistic reagents, STP and furfural, STP and CPB,STP and benzaldehyde, STP and cinnamaldehyde, benzaldehyde and benzaldehyde were obtained. The optimum synergistic effect ratio of five groups of reagents was studied by weightlessness method. The results showed that 0.14: 0.06 0. 12: 0. 12: 0. 10: 0. 10: 0. 16: 0. 16: 0.04 and 0. 16: 0.04. The potentiodynamic polarization curves showed that all the five synergistic inhibitors were mixed inhibitors. Although the synergistic corrosion inhibitor is superior to one component corrosion inhibitor, it still has not achieved the best corrosion inhibition effect. An inorganic salt, a vanadium complex and an organic compound inhibitor, J-HM.J-HM, which is composed of a inorganic salt, a vanadium complex and an organic compound, were prepared by blending several kinds of reagents. The optimum ratio of each component is as follows: inorganic salt 0.8g dm-3,. Organic 1. 2 g dm-3, vanadium complex 1. 0 g dm-3. The corrosion inhibition of aluminum in 5% earic acid by J-HM was investigated by weightlessness and potentiodynamic polarization curves. The results showed that the lowest corrosion rate of aluminum was 0.83 g m-2 h-1 + J-HM with the addition of J-HM. The highest corrosion inhibition rate of J-HM was 99.03g / h ~ (-1) J-HM. The optimum concentration of J-HM was 2 g / dm-3.. The corrosion inhibition effect is good when the concentration of earic acid is less than 6 and the temperature is less than 50 鈩，

本文編號：2366857