A 40 Cr steel was formed into a chain-wheel using a warm extrusion technology. The surface roughness and micro-structure, micro-hardness and phases of the extruded samples at different temperatures were analyzed using...A 40 Cr steel was formed into a chain-wheel using a warm extrusion technology. The surface roughness and micro-structure, micro-hardness and phases of the extruded samples at different temperatures were analyzed using a three-dimensional optical microscope(OM), micro-hardness tester, and X-ray diffraction(XRD), respectively. The morphologies, chemical element distributions and phases of worn tracks at the extrusion temperatures of 550, 650 and 750 ℃ were analyzed using a scanning electron microscopy(SEM), energy disperse spectroscopy(EDS), and XRD, respectively. The friction-wear behaviors of extruded samples under oil-lubrication condition were observed using a wear test. And the effects of extrusion temperatures on the wear mechanism were discussed. The results show that residual austenite and pearlite exist on the sample at the extrusion temperature of 550 ℃ with the corresponding grain size and surface micro-hardness of 32.7 nm and 370.33 HV, respectively. The average coefficient of friction(COF) of extruded sample at the temperature of 550 ℃ is 0.196 5, and the wear mechanism is fatigue and abrasive wear. While the acicular martensite exists on the extruded samples at the extrusion temperatures of 650 and 750 ℃, the corresponding grain sizes are 30.0 and 29.1 nm, respectively. The average COF(coefficient of friction) of extruded sample at the temperatures of 650 and 750 ℃ are 0.187 4 and 0.163 6, respectively, and the wear mechanism is abrasive wear. As a result, the friction performance of extruded sample at the temperatures of 650 and 750 ℃ is better than that at the temperature of 550 ℃.展开更多
Cobalt tetra（2,4-dichloro-1,3,5-triazine）aminophthalocyanine （CoPc） was immobilized covalently on activated carbon fiber （ACF） felt to obtain CoPc-modified ACF （CoPc-ACF） catalyst, and an electrocatalytic oxid...Cobalt tetra（2,4-dichloro-1,3,5-triazine）aminophthalocyanine （CoPc） was immobilized covalently on activated carbon fiber （ACF） felt to obtain CoPc-modified ACF （CoPc-ACF） catalyst, and an electrocatalytic oxidation system using CoPc-ACF as the anode was constructed. The electrocatalytic oxidation of Acid Red 1 （ARI） was investigated in aqueous solution by an UV-vis spectrophotometer and UPLC. The results indicated that AR1 could be eliminated efficiently in this electrocatalytic oxidation system. In addition, the results of FTIR, TOC and GC-MS suggested that the electrocatalytic oxidation experienced the decoloration achieved by destroying the azo linkage and the further mineralization due to the cleavages of benzene ring and naphthalene ring. The intermediates were mainly small molecular compounds such as maleic acid and succinic acid, etc. Re- petitive tests showed that CoPc-ACF can maintain high electrocatalytic activity over several cycles. The further EPR spin-trap experiments indicated that the hydroxyl radicals did not dominate the reaction in this electrocatalytic system, which was com- pletely different from the traditional electro-Fenton system. Based on the non-radical reaction mechanism, the CoPc-modified ACF electrocatalyst has potential application in treating actual dyestuffs wastewaters, which are accompanied with high concentration of hydroxyl radical scavengers such as chlorine ions and additives in the textile printing and dyeing industry.展开更多
基金Funded by Jiangsu Province Science and Technology Support Program(Industry)(No.BE2014818)the Research Project of Scientific Research Innovation for Graduate Students of Jiangsu Province(No.KYLX16-0631)
文摘A 40 Cr steel was formed into a chain-wheel using a warm extrusion technology. The surface roughness and micro-structure, micro-hardness and phases of the extruded samples at different temperatures were analyzed using a three-dimensional optical microscope(OM), micro-hardness tester, and X-ray diffraction(XRD), respectively. The morphologies, chemical element distributions and phases of worn tracks at the extrusion temperatures of 550, 650 and 750 ℃ were analyzed using a scanning electron microscopy(SEM), energy disperse spectroscopy(EDS), and XRD, respectively. The friction-wear behaviors of extruded samples under oil-lubrication condition were observed using a wear test. And the effects of extrusion temperatures on the wear mechanism were discussed. The results show that residual austenite and pearlite exist on the sample at the extrusion temperature of 550 ℃ with the corresponding grain size and surface micro-hardness of 32.7 nm and 370.33 HV, respectively. The average coefficient of friction(COF) of extruded sample at the temperature of 550 ℃ is 0.196 5, and the wear mechanism is fatigue and abrasive wear. While the acicular martensite exists on the extruded samples at the extrusion temperatures of 650 and 750 ℃, the corresponding grain sizes are 30.0 and 29.1 nm, respectively. The average COF(coefficient of friction) of extruded sample at the temperatures of 650 and 750 ℃ are 0.187 4 and 0.163 6, respectively, and the wear mechanism is abrasive wear. As a result, the friction performance of extruded sample at the temperatures of 650 and 750 ℃ is better than that at the temperature of 550 ℃.
基金supported by the National Natural Science Foundation of China(51133006,51103133,51003096)Program for Changjiang Scholars and Innovative Research Team in University(0654)Textile Vision Science & Education Fund and Science Foundation of Zhejiang SciTech University(1001803-Y)
文摘Cobalt tetra（2,4-dichloro-1,3,5-triazine）aminophthalocyanine （CoPc） was immobilized covalently on activated carbon fiber （ACF） felt to obtain CoPc-modified ACF （CoPc-ACF） catalyst, and an electrocatalytic oxidation system using CoPc-ACF as the anode was constructed. The electrocatalytic oxidation of Acid Red 1 （ARI） was investigated in aqueous solution by an UV-vis spectrophotometer and UPLC. The results indicated that AR1 could be eliminated efficiently in this electrocatalytic oxidation system. In addition, the results of FTIR, TOC and GC-MS suggested that the electrocatalytic oxidation experienced the decoloration achieved by destroying the azo linkage and the further mineralization due to the cleavages of benzene ring and naphthalene ring. The intermediates were mainly small molecular compounds such as maleic acid and succinic acid, etc. Re- petitive tests showed that CoPc-ACF can maintain high electrocatalytic activity over several cycles. The further EPR spin-trap experiments indicated that the hydroxyl radicals did not dominate the reaction in this electrocatalytic system, which was com- pletely different from the traditional electro-Fenton system. Based on the non-radical reaction mechanism, the CoPc-modified ACF electrocatalyst has potential application in treating actual dyestuffs wastewaters, which are accompanied with high concentration of hydroxyl radical scavengers such as chlorine ions and additives in the textile printing and dyeing industry.
