The atmospheric corrosion behavior of pure copper exposed for three years in Turpan, China, which is a typical hot and dry atmosphere environment, was investigated using mass-loss tests, morphology observations, com...The atmospheric corrosion behavior of pure copper exposed for three years in Turpan, China, which is a typical hot and dry atmosphere environment, was investigated using mass-loss tests, morphology observations, composition analyses, and electrochemical techniques. The results indicated that the annual corrosion rate of pure copper was approximately 2.90 μm/a. An uneven distribution of corrosion products was observed by scanning electron microscopy; this uneven distribution was attributed to the dehydration process during wet–dry and cold–hot cycles, and the compositions mainly consisted of cuprite （Cu2O） and atacamite （Cu2Cl（OH）3）. Electrochemical measurements showed that deposits on copper improved its resistance to corrosion and the protectiveness decreased with increasing temperature. On the other hand, results obtained using the scanning vibrating electrode technique showed that the porous and uneven structure of the deposit layer generated a spatial separation of cathodic and anodic reaction sites, which accelerated the corrosion process in wet and rainy weather.展开更多
The rate constants of the reaction between hydroxyl radical （OH-） and dimethyl sulfide （DMS） were investigated by using the relative methods in air, N2, and 02. Strong influences of ground state oxygen O（3p） on ...The rate constants of the reaction between hydroxyl radical （OH-） and dimethyl sulfide （DMS） were investigated by using the relative methods in air, N2, and 02. Strong influences of ground state oxygen O（3p） on DMS consumption were found by the photolysis of HONO and CH3ONO as OH. sources, and the rate constants obtained in these systems varied significantly. The rate constants of the reaction between DMS and OH- （generated by photolysis of H2 O2） at room temperature were 8.56 × 10^-12, 11.31× 10^-12, and 4.50× 10^-12 cm3/（molecule.s）, in air, O2, and N2, respectively. The temperature dependence of the rate constants for OH- with DMS over the temperature range of 287-338 K was also investigated in nitrogen and air, and the Arrhenius expression was obtained as follows： kaire=（7.24±0.28）× 10^-13exp[（770.7±E97.2）/T], kN2 =（3.40±0.15） × 10^-11 exp[-- （590.3±165.9）/T].展开更多
基金Project(51222106)supported by the National Natural Science Foundation of ChinaProject(FRF-TP-14-011C1)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2014CB643300)supported by the National Basic Research Program of China
文摘The atmospheric corrosion behavior of pure copper exposed for three years in Turpan, China, which is a typical hot and dry atmosphere environment, was investigated using mass-loss tests, morphology observations, composition analyses, and electrochemical techniques. The results indicated that the annual corrosion rate of pure copper was approximately 2.90 μm/a. An uneven distribution of corrosion products was observed by scanning electron microscopy; this uneven distribution was attributed to the dehydration process during wet–dry and cold–hot cycles, and the compositions mainly consisted of cuprite （Cu2O） and atacamite （Cu2Cl（OH）3）. Electrochemical measurements showed that deposits on copper improved its resistance to corrosion and the protectiveness decreased with increasing temperature. On the other hand, results obtained using the scanning vibrating electrode technique showed that the porous and uneven structure of the deposit layer generated a spatial separation of cathodic and anodic reaction sites, which accelerated the corrosion process in wet and rainy weather.
基金This work was supported by the National Natural Science Foundation of China （No.20677067 and No.20577064） and the National Basic Research Pro- gram of China （No.2005CB422201）.
文摘The rate constants of the reaction between hydroxyl radical （OH-） and dimethyl sulfide （DMS） were investigated by using the relative methods in air, N2, and 02. Strong influences of ground state oxygen O（3p） on DMS consumption were found by the photolysis of HONO and CH3ONO as OH. sources, and the rate constants obtained in these systems varied significantly. The rate constants of the reaction between DMS and OH- （generated by photolysis of H2 O2） at room temperature were 8.56 × 10^-12, 11.31× 10^-12, and 4.50× 10^-12 cm3/（molecule.s）, in air, O2, and N2, respectively. The temperature dependence of the rate constants for OH- with DMS over the temperature range of 287-338 K was also investigated in nitrogen and air, and the Arrhenius expression was obtained as follows： kaire=（7.24±0.28）× 10^-13exp[（770.7±E97.2）/T], kN2 =（3.40±0.15） × 10^-11 exp[-- （590.3±165.9）/T].
