The conventional mass loss tests and the electrochemical techniques were used to study the inhibition action of LiOH and Na 2MoO 4 either individually or in different combination for copper nickel alloy in boiling 65%...The conventional mass loss tests and the electrochemical techniques were used to study the inhibition action of LiOH and Na 2MoO 4 either individually or in different combination for copper nickel alloy in boiling 65% LiBr solution. It indicates that the corrosion rate of copper nickel is decreased when LiOH or Na 2MoO 4 is added to the solution individually. LiOH concentration has a double effect on the corrosion behavior of copper nickel. Low concentration is benefit to forming oxide film. High concentration results in dissolution of oxide film. The optimal concentration of LiOH is 0.15?mol/L. The dissolution of copper nickel is effectively prevented when adding 200?mg/L Na 2MoO 4 to boiling 65% LiBr solution with 0.15?mol/L LiOH. The inhibition mechanism is considered that the films of Cu, Ni, Mo oxides and deposited nonprotective in soluble CuBr on the surface of metal could prevent Br - ion from absorption, which prevent alloy dissolving.展开更多
The effects of PMA/SbBr3 inhibitor on copper and copper-nickel alloy in 55%LiBr solution were investigated by chemical immersion and electrochemical measurements. The results indicate that in boiling 55%LiBr solution ...The effects of PMA/SbBr3 inhibitor on copper and copper-nickel alloy in 55%LiBr solution were investigated by chemical immersion and electrochemical measurements. The results indicate that in boiling 55%LiBr solution containing PMA/SbBr3 inhibitor, corrosion rates of copper and copper-nickel alloy are 67.48μm/a and 38.14μm/a, respectively. Since both anodic and cathodic electrochemical reactions can be inhibited, PMA/SbBr3 belongs to complex inhibitor. PMA has the effect of inhibiting hydrogen evolution and [PMo<sup>12 O<sup>40 ]3- , the anion of PMA, has a strong oxidizing effect. Sb3+ also shows an oxidizing effect. It may exist in LiBr solutions stably with PMA. Because of the synergistic effect of PMA and Sb3+ , a protective film, comprising CuO, Cu2O and Sb, formed on copper and copper-nickel alloy surface may prevent Br-from diffusing to the surface of metals. As a result, the anticorrosion performance of copper and copper-nickel alloy may be improved.展开更多
The anticorrosion performance of carbon steel in 55 % LiBr solution containing PMA/SbBr3 inhibitor was studied by weight-loss tests, electrochemical measurements and surface analysis. In 55 %LiBr＋PMA/SbBr3 solution, ...The anticorrosion performance of carbon steel in 55 % LiBr solution containing PMA/SbBr3 inhibitor was studied by weight-loss tests, electrochemical measurements and surface analysis. In 55 %LiBr＋PMA/SbBr3 solution, corrosion rates of carbon steel at 145 ℃, 175℃, 190℃ and 240℃ are 18.32μm·a^-1 , 27.68μm·a^-1, 53.58μm·a^-1 and 73. 78μm·a^-1 , respectively. PMA/SbBr3 inhibitor may inhibit the corrosion of carbon steel in 55% LiBr solution effectively. Especially, it shows an excellent corrosion inhibition performance at high temperature. Both anodic and cathodic reactions of carbon steel may be inhibited by PMA/SbBr3 inhibitor, so it may be classified as mixed inhibitor. In 55%LiBr＋PMA/SbBr3 solution, the apparent activation energy of the corrosion reaction of carbon steel is 29. 61 kJ·mol^-1. The corrosion inhibition mechanism of PMA/SbBr3 is suggested as follows： PMA has the effect of inhibiting hydrogen evolution and a strong oxidizing property; Sb^3＋ also exhibits oxidizing properties, and can exist stably with PMA in LiBr solutions; the passive film comprising Fe2O3 and antimony formed on carbon steel surface may prevent Brfrom diffusing into the metal surface due to the synergistic effect of PMA and Sb^3＋ ; As a result, the anticorrosion performance of carbon steel may be improved by PMA/SbBr3 inhibitor in 55% LiBr solution.展开更多
By using electrochemical and weight loss methods, the effect of MoO42-on the corrosion behaviors of low alloy steel was investigated in the 55%LiBr＋0.07 mol/L LiOH solution at high temperature. The results show that ...By using electrochemical and weight loss methods, the effect of MoO42-on the corrosion behaviors of low alloy steel was investigated in the 55%LiBr＋0.07 mol/L LiOH solution at high temperature. The results show that MoO42 , being an anodic inhibitor, would form a passive film rapidly and impede both anodic and cathodic reactions. Moreover, Na2MoO4 effectively prevents corrosion in 55%LiBr＋0.07 mol/L LiOH solution when its concentration is higher than 200 mg/L. Some elements of alloy, such as chromium and nickel, may cause the widening of passive potential region and the decrease of passive density, which indicates that the corrosion resistance increases. AES analysis shows that molybdenum participates in forming a protection film. The synergistic effect between chromium and molybdenum induces Cr-steel to be in passive state in lower Na2MoO4 concentration.展开更多
文摘The conventional mass loss tests and the electrochemical techniques were used to study the inhibition action of LiOH and Na 2MoO 4 either individually or in different combination for copper nickel alloy in boiling 65% LiBr solution. It indicates that the corrosion rate of copper nickel is decreased when LiOH or Na 2MoO 4 is added to the solution individually. LiOH concentration has a double effect on the corrosion behavior of copper nickel. Low concentration is benefit to forming oxide film. High concentration results in dissolution of oxide film. The optimal concentration of LiOH is 0.15?mol/L. The dissolution of copper nickel is effectively prevented when adding 200?mg/L Na 2MoO 4 to boiling 65% LiBr solution with 0.15?mol/L LiOH. The inhibition mechanism is considered that the films of Cu, Ni, Mo oxides and deposited nonprotective in soluble CuBr on the surface of metal could prevent Br - ion from absorption, which prevent alloy dissolving.
文摘The effects of PMA/SbBr3 inhibitor on copper and copper-nickel alloy in 55%LiBr solution were investigated by chemical immersion and electrochemical measurements. The results indicate that in boiling 55%LiBr solution containing PMA/SbBr3 inhibitor, corrosion rates of copper and copper-nickel alloy are 67.48μm/a and 38.14μm/a, respectively. Since both anodic and cathodic electrochemical reactions can be inhibited, PMA/SbBr3 belongs to complex inhibitor. PMA has the effect of inhibiting hydrogen evolution and [PMo<sup>12 O<sup>40 ]3- , the anion of PMA, has a strong oxidizing effect. Sb3+ also shows an oxidizing effect. It may exist in LiBr solutions stably with PMA. Because of the synergistic effect of PMA and Sb3+ , a protective film, comprising CuO, Cu2O and Sb, formed on copper and copper-nickel alloy surface may prevent Br-from diffusing to the surface of metals. As a result, the anticorrosion performance of copper and copper-nickel alloy may be improved.
文摘The anticorrosion performance of carbon steel in 55 % LiBr solution containing PMA/SbBr3 inhibitor was studied by weight-loss tests, electrochemical measurements and surface analysis. In 55 %LiBr＋PMA/SbBr3 solution, corrosion rates of carbon steel at 145 ℃, 175℃, 190℃ and 240℃ are 18.32μm·a^-1 , 27.68μm·a^-1, 53.58μm·a^-1 and 73. 78μm·a^-1 , respectively. PMA/SbBr3 inhibitor may inhibit the corrosion of carbon steel in 55% LiBr solution effectively. Especially, it shows an excellent corrosion inhibition performance at high temperature. Both anodic and cathodic reactions of carbon steel may be inhibited by PMA/SbBr3 inhibitor, so it may be classified as mixed inhibitor. In 55%LiBr＋PMA/SbBr3 solution, the apparent activation energy of the corrosion reaction of carbon steel is 29. 61 kJ·mol^-1. The corrosion inhibition mechanism of PMA/SbBr3 is suggested as follows： PMA has the effect of inhibiting hydrogen evolution and a strong oxidizing property; Sb^3＋ also exhibits oxidizing properties, and can exist stably with PMA in LiBr solutions; the passive film comprising Fe2O3 and antimony formed on carbon steel surface may prevent Brfrom diffusing into the metal surface due to the synergistic effect of PMA and Sb^3＋ ; As a result, the anticorrosion performance of carbon steel may be improved by PMA/SbBr3 inhibitor in 55% LiBr solution.
文摘By using electrochemical and weight loss methods, the effect of MoO42-on the corrosion behaviors of low alloy steel was investigated in the 55%LiBr＋0.07 mol/L LiOH solution at high temperature. The results show that MoO42 , being an anodic inhibitor, would form a passive film rapidly and impede both anodic and cathodic reactions. Moreover, Na2MoO4 effectively prevents corrosion in 55%LiBr＋0.07 mol/L LiOH solution when its concentration is higher than 200 mg/L. Some elements of alloy, such as chromium and nickel, may cause the widening of passive potential region and the decrease of passive density, which indicates that the corrosion resistance increases. AES analysis shows that molybdenum participates in forming a protection film. The synergistic effect between chromium and molybdenum induces Cr-steel to be in passive state in lower Na2MoO4 concentration.
