Mierostrueture of the Fe-based alloy hardfaeing coating reinforced by TiC-VC particles was investigated by means of SEM, TEM, XRD and EPMA. The thermodynamics and effect of elements on the carbides were discussed. The...Mierostrueture of the Fe-based alloy hardfaeing coating reinforced by TiC-VC particles was investigated by means of SEM, TEM, XRD and EPMA. The thermodynamics and effect of elements on the carbides were discussed. The result shows that TiC-VC carbides can be formed during arc welding. Carbides with particle size of 2 ～4μm are uniformly dispersed in the matrix. Evidently the covering components and their amount affect the microstrueture and hardness of the coatings. An excellent microstructure and hardness of hardfacing coating were obtained, while the amount of graphite, FeTi and FeV was controlled within the range of 8%- 10%, 15%- 18% and 8%- 12%, respectively.展开更多
This paper presents the use of computed tomography for the evaluation of hardfacing. The method used in this research is hardfacing by tungsten inert gas using alloy wires of wear resistant layers. This paper discusse...This paper presents the use of computed tomography for the evaluation of hardfacing. The method used in this research is hardfacing by tungsten inert gas using alloy wires of wear resistant layers. This paper discusses the latest materials used for hardfacing and their application. It characterizes the defects of obtained hardfacing and impact of the type of wire on the concentration of defects. It further, the basic mechanical properties of coatings were determined. The results are subjected to qualitative and quantitative analysis. The smallest average percentage of defects in relation to the overall surface is observed for the hardfacing EL-600 HB, which amounts to 1.5%. The highest average percentage of defects in relation to the overall surface is observed for the hardfacing EL-500 HB, which amounts to 7.2%. The chemical composition of hardfacing has been presented.展开更多
The Fe-Cr-C flux-cored wires with 0 wt.%, 0.63 wt.%, 2.54 wt.% and 5.08 wt.% additions of nano-Y203 were developed in this work. And the different hypereutectic Fe-Cr-C hardfacing coatings were prepared. The phase str...The Fe-Cr-C flux-cored wires with 0 wt.%, 0.63 wt.%, 2.54 wt.% and 5.08 wt.% additions of nano-Y203 were developed in this work. And the different hypereutectic Fe-Cr-C hardfacing coatings were prepared. The phase structures of the coatings were determined by X-ray diffraction. The microstructures were observed by optical microscopy. The morphologies of the hypereutectic Fe-Cr-C hardfacing coatings were observed by a field emission scanning electron microscope equipped with an X-ray energy disper- sive spectrometer. The effectiveness ofY203 as heterogeneous nuclei of primary M7C3 was calculated with the misfit theory. The ex- periment results showed that, the microstructures of the hypereutectic Fe-Cr-C hardfacing coatings consisted of M7C3, ？-Fe and a-Fe phases. With the increase of nano-Y203 additives, primary M7C3 in hypereutectic Fe-Cr-C coatings could be refined gradually. The average size of the primary M7C3 was the minimum, which was 22 pro, when nano-Y203 additive was 2.54 wt.%. The calculated re- sults showed that, the two-dimensional lattice misfit between the face （001） of Y203 and face （100） of orthorhombic M7C3 was 4.911%, which indicated that Y203 as heterogeneous nuclei of M7C3 was middle effective to refine the primary M7C3.展开更多
为了提高镍基堆焊层的耐磨性能,采用改进型等离子堆焊枪,从等离子焰尾部将镍包碳化硅陶瓷粉末注入堆焊熔池,在4Cr5Mo Si V1模具钢表面制备碳化物陶瓷增强复合焊层。X射线衍射分析表明采用枪外熔注制备的堆焊层组织中含有大量原位生成的...为了提高镍基堆焊层的耐磨性能,采用改进型等离子堆焊枪,从等离子焰尾部将镍包碳化硅陶瓷粉末注入堆焊熔池,在4Cr5Mo Si V1模具钢表面制备碳化物陶瓷增强复合焊层。X射线衍射分析表明采用枪外熔注制备的堆焊层组织中含有大量原位生成的碳化物和大量的硅化物与硼化物;金相显微分析表明堆焊层颗粒状碳化物组织分布均匀,碳化物粒度沿焊层表面至堆焊界面依次减小;常温及高温摩擦磨损试验表明制备的堆焊层具有较高的显微硬度与优异的耐高温磨损性能。展开更多
文摘Mierostrueture of the Fe-based alloy hardfaeing coating reinforced by TiC-VC particles was investigated by means of SEM, TEM, XRD and EPMA. The thermodynamics and effect of elements on the carbides were discussed. The result shows that TiC-VC carbides can be formed during arc welding. Carbides with particle size of 2 ～4μm are uniformly dispersed in the matrix. Evidently the covering components and their amount affect the microstrueture and hardness of the coatings. An excellent microstructure and hardness of hardfacing coating were obtained, while the amount of graphite, FeTi and FeV was controlled within the range of 8%- 10%, 15%- 18% and 8%- 12%, respectively.
文摘This paper presents the use of computed tomography for the evaluation of hardfacing. The method used in this research is hardfacing by tungsten inert gas using alloy wires of wear resistant layers. This paper discusses the latest materials used for hardfacing and their application. It characterizes the defects of obtained hardfacing and impact of the type of wire on the concentration of defects. It further, the basic mechanical properties of coatings were determined. The results are subjected to qualitative and quantitative analysis. The smallest average percentage of defects in relation to the overall surface is observed for the hardfacing EL-600 HB, which amounts to 1.5%. The highest average percentage of defects in relation to the overall surface is observed for the hardfacing EL-500 HB, which amounts to 7.2%. The chemical composition of hardfacing has been presented.
基金supported by National Natural Science Foundation of China(51271163,51471148)
文摘The Fe-Cr-C flux-cored wires with 0 wt.%, 0.63 wt.%, 2.54 wt.% and 5.08 wt.% additions of nano-Y203 were developed in this work. And the different hypereutectic Fe-Cr-C hardfacing coatings were prepared. The phase structures of the coatings were determined by X-ray diffraction. The microstructures were observed by optical microscopy. The morphologies of the hypereutectic Fe-Cr-C hardfacing coatings were observed by a field emission scanning electron microscope equipped with an X-ray energy disper- sive spectrometer. The effectiveness ofY203 as heterogeneous nuclei of primary M7C3 was calculated with the misfit theory. The ex- periment results showed that, the microstructures of the hypereutectic Fe-Cr-C hardfacing coatings consisted of M7C3, ？-Fe and a-Fe phases. With the increase of nano-Y203 additives, primary M7C3 in hypereutectic Fe-Cr-C coatings could be refined gradually. The average size of the primary M7C3 was the minimum, which was 22 pro, when nano-Y203 additive was 2.54 wt.%. The calculated re- sults showed that, the two-dimensional lattice misfit between the face （001） of Y203 and face （100） of orthorhombic M7C3 was 4.911%, which indicated that Y203 as heterogeneous nuclei of M7C3 was middle effective to refine the primary M7C3.
文摘为了提高镍基堆焊层的耐磨性能,采用改进型等离子堆焊枪,从等离子焰尾部将镍包碳化硅陶瓷粉末注入堆焊熔池,在4Cr5Mo Si V1模具钢表面制备碳化物陶瓷增强复合焊层。X射线衍射分析表明采用枪外熔注制备的堆焊层组织中含有大量原位生成的碳化物和大量的硅化物与硼化物;金相显微分析表明堆焊层颗粒状碳化物组织分布均匀,碳化物粒度沿焊层表面至堆焊界面依次减小;常温及高温摩擦磨损试验表明制备的堆焊层具有较高的显微硬度与优异的耐高温磨损性能。
