Stainless steel (SS) 410 is widely used in many components of nuclear reactors due to its good corrosion resistance and high strength. However, wear is a major issue of these components due to its continuous sliding. ...Stainless steel (SS) 410 is widely used in many components of nuclear reactors due to its good corrosion resistance and high strength. However, wear is a major issue of these components due to its continuous sliding. SS 420 and Colmonoy 5 particles were deposited over SS 410 substrate by laser cladding process. Then, X-ray diffraction was used to find the phases present after cladding process. Further, coating morphologies were analysed by scanning electron microscopy (SEM) twinned with energy-dispersive spectroscopy. The obtained morphology indicates the hard laves phase present in the Colmonoy 5 cladding surface and needle-like structure in SS 420 cladding surface. Then, Vickers microhardness test was carried out in order to study the hardness and load-carrying capacity of the cladding specimen. Among those, Colmonoy 5 cladding specimen provide higher hardness due to the presence of laves phase formation. Then, the dry sliding wear study was conducted to calculate the mass loss after 2500 m of sliding. The combined effect of hardness and laves phase formation were reflected in dry sliding wear study analysis of the specimens. Then, to study the wear mechanism and roughness, worn surface morphologies were captured using SEM and white light interferometer, respectively.展开更多
In the present study, a grade of stainless steel （SS, 410） and copper plates were joined through diffusion bonding by using a nickel interlayer at temperature range of 800-950℃. These were performed through pressin...In the present study, a grade of stainless steel （SS, 410） and copper plates were joined through diffusion bonding by using a nickel interlayer at temperature range of 800-950℃. These were performed through pressing the specimens under a pressure of 12 MPa for 60 min under 1.33×10-2 Pa （10-4 torr） vacuum. The microstructure and phase constitution near the diffusion bonding interface of Cu/Ni and Ni/SS were studied by optical microscopy （OM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD） and an elemental analyses through energy dispersive spectrometry （EDS）. The results indicated that an obvious diffusion zone was formed near both Cu/Ni and Ni/SS interfaces during the vacuum diffusion bonding. The thickness of reaction layer in both interfaces was increased with increasing process temperature. The diffusion transition region near the Cu/Ni and Ni/SS interfaces consist of complete solid solution zone and various phases based on （Fe, Ni）, （Fe, Cr, Ni） and （Fe, Cr）, respectively. From EDS results, three different mixtures of phases were distinguished in SS-Ni interface. The activation energy and rate constant were determined for the growth of these reaction layers and the values become maximum for the （γFe＋Cr＋αFe＋Cr）.phase mixture.展开更多
基金Ministry of Science and Technology(MOST),Taiwan,China,for providing financial support to carry out this research work.
文摘Stainless steel (SS) 410 is widely used in many components of nuclear reactors due to its good corrosion resistance and high strength. However, wear is a major issue of these components due to its continuous sliding. SS 420 and Colmonoy 5 particles were deposited over SS 410 substrate by laser cladding process. Then, X-ray diffraction was used to find the phases present after cladding process. Further, coating morphologies were analysed by scanning electron microscopy (SEM) twinned with energy-dispersive spectroscopy. The obtained morphology indicates the hard laves phase present in the Colmonoy 5 cladding surface and needle-like structure in SS 420 cladding surface. Then, Vickers microhardness test was carried out in order to study the hardness and load-carrying capacity of the cladding specimen. Among those, Colmonoy 5 cladding specimen provide higher hardness due to the presence of laves phase formation. Then, the dry sliding wear study was conducted to calculate the mass loss after 2500 m of sliding. The combined effect of hardness and laves phase formation were reflected in dry sliding wear study analysis of the specimens. Then, to study the wear mechanism and roughness, worn surface morphologies were captured using SEM and white light interferometer, respectively.
文摘In the present study, a grade of stainless steel （SS, 410） and copper plates were joined through diffusion bonding by using a nickel interlayer at temperature range of 800-950℃. These were performed through pressing the specimens under a pressure of 12 MPa for 60 min under 1.33×10-2 Pa （10-4 torr） vacuum. The microstructure and phase constitution near the diffusion bonding interface of Cu/Ni and Ni/SS were studied by optical microscopy （OM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD） and an elemental analyses through energy dispersive spectrometry （EDS）. The results indicated that an obvious diffusion zone was formed near both Cu/Ni and Ni/SS interfaces during the vacuum diffusion bonding. The thickness of reaction layer in both interfaces was increased with increasing process temperature. The diffusion transition region near the Cu/Ni and Ni/SS interfaces consist of complete solid solution zone and various phases based on （Fe, Ni）, （Fe, Cr, Ni） and （Fe, Cr）, respectively. From EDS results, three different mixtures of phases were distinguished in SS-Ni interface. The activation energy and rate constant were determined for the growth of these reaction layers and the values become maximum for the （γFe＋Cr＋αFe＋Cr）.phase mixture.
