A binary Fe-Al alloyed layer was synthesized on 45 steel by means of double glow plasma surface alloying technique. The corrosion-resisting layer prepared is composed of a sedimentary layer and a diffusion layer, with...A binary Fe-Al alloyed layer was synthesized on 45 steel by means of double glow plasma surface alloying technique. The corrosion-resisting layer prepared is composed of a sedimentary layer and a diffusion layer, with a total thickness of about 180 μm. The aluminum content of the alloyed layer shows gradual change from surface to the inside of substrate. The ideal profile is beneficial to the metallurgical bonding of the surface alloying layer with substrate materials. The microstructure of both layers consists of the Fe-Al intermetallic compound, which is FeAl with B2 structure in the sedimentary layer and Fe3Al with incompletely ordered DO3 structure in the diffusion layer. The protective film exhibits high micro-hardness. In comparison with the substrate of 45 steel, the corrosion resistance of the aluminized sample is much higher in 2.0% Na2S and 0.05 mol/L Na2SO4 + 0.5 mol/L NaCl mixed solutions.展开更多
The hot corrosion behaviour of a modified Ti3Al-based alloy under thin Na2SO4deposit film was investigated at910and950°C in air.The corrosion product was identified by XRD and its morphologies on the surface and ...The hot corrosion behaviour of a modified Ti3Al-based alloy under thin Na2SO4deposit film was investigated at910and950°C in air.The corrosion product was identified by XRD and its morphologies on the surface and cross-section were observed bySEM.The alloy suffered from considerable hot corrosion attack.The mass gain versus time curves obtained by TGA exhibited tworegions of different kinetics.The whole corroded layer consisted of loose and porous mixture oxides of TiO2,Nb2O5and Al2O3.Numerous small nodules of corrosion product were observed.An illustrative schematic was established to describe the formationprocess of such nodules.It seemed that the refractory oxides played a significantly important role in determining the development ofhot corrosion attack.展开更多
基金Project(BK2005128) supported by the Natural Science Foundation of Jiangsu Province, China
文摘A binary Fe-Al alloyed layer was synthesized on 45 steel by means of double glow plasma surface alloying technique. The corrosion-resisting layer prepared is composed of a sedimentary layer and a diffusion layer, with a total thickness of about 180 μm. The aluminum content of the alloyed layer shows gradual change from surface to the inside of substrate. The ideal profile is beneficial to the metallurgical bonding of the surface alloying layer with substrate materials. The microstructure of both layers consists of the Fe-Al intermetallic compound, which is FeAl with B2 structure in the sedimentary layer and Fe3Al with incompletely ordered DO3 structure in the diffusion layer. The protective film exhibits high micro-hardness. In comparison with the substrate of 45 steel, the corrosion resistance of the aluminized sample is much higher in 2.0% Na2S and 0.05 mol/L Na2SO4 + 0.5 mol/L NaCl mixed solutions.
基金Projects(51271191,51571205)supported by the National Natural Science Foundation of China
文摘The hot corrosion behaviour of a modified Ti3Al-based alloy under thin Na2SO4deposit film was investigated at910and950°C in air.The corrosion product was identified by XRD and its morphologies on the surface and cross-section were observed bySEM.The alloy suffered from considerable hot corrosion attack.The mass gain versus time curves obtained by TGA exhibited tworegions of different kinetics.The whole corroded layer consisted of loose and porous mixture oxides of TiO2,Nb2O5and Al2O3.Numerous small nodules of corrosion product were observed.An illustrative schematic was established to describe the formationprocess of such nodules.It seemed that the refractory oxides played a significantly important role in determining the development ofhot corrosion attack.
