The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform

W Ke - One of the best experts on this subject based on the ideXlab platform.

  • short time oxidation of alloy 690 in high temperature and high Pressure Steam and water
    Journal of Materials Science & Technology, 2012
    Co-Authors: Fa Huang, J Q Wang, W Ke
    Abstract:

    The oxidation behavior of alloy 690 exposed to high-temperature and high-Pressure Steam and water at 280 degrees C for 1 h was investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). In high-temperature and high-Pressure Steam, the oxide film is composed of an outermost Ni-rich hydroxides layer, an intermediate layer of hydroxides and oxides enriched in Cr, an inner oxide layer. The film formed in high-temperature water is similar to that in Steam, except for missing the Ni-rich hydroxides layer. Samples with different surface finishes (electropolished, mechanically polished, ground, and as-received) were prepared for comparison. A general increase of the oxide thickness with the degree of surface roughness is observed. The equivalent oxide thicknesses lie in the range of 100-200 nm for the as-received samples, 150-250 nm for the samples ground to 400(#) and 10-20 nm for the samples ground to 1500(#), mechanically polished, and electropolished.

Fa Huang - One of the best experts on this subject based on the ideXlab platform.

  • short time oxidation of alloy 690 in high temperature and high Pressure Steam and water
    Journal of Materials Science & Technology, 2012
    Co-Authors: Fa Huang, J Q Wang, W Ke
    Abstract:

    The oxidation behavior of alloy 690 exposed to high-temperature and high-Pressure Steam and water at 280 degrees C for 1 h was investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). In high-temperature and high-Pressure Steam, the oxide film is composed of an outermost Ni-rich hydroxides layer, an intermediate layer of hydroxides and oxides enriched in Cr, an inner oxide layer. The film formed in high-temperature water is similar to that in Steam, except for missing the Ni-rich hydroxides layer. Samples with different surface finishes (electropolished, mechanically polished, ground, and as-received) were prepared for comparison. A general increase of the oxide thickness with the degree of surface roughness is observed. The equivalent oxide thicknesses lie in the range of 100-200 nm for the as-received samples, 150-250 nm for the samples ground to 400(#) and 10-20 nm for the samples ground to 1500(#), mechanically polished, and electropolished.

Manish Agarwal - One of the best experts on this subject based on the ideXlab platform.

  • High Power Diode Laser Surface Treatment to Minimize Droplet Erosion of Low Pressure Steam Turbine Moving Blades
    Journal of Materials Engineering and Performance, 2009
    Co-Authors: B.s. Mann, Vivek Arya, B.k. Pant, Manish Agarwal
    Abstract:

    This article deals with the high power diode laser (HPDL) surface treatment to overcome water droplet erosion of Low Pressure Steam Turbine (LPST) moving blades used in high rating conventional, critical and super critical thermal power plants. The materials generally used in these Steam turbines are titanium alloy (Ti6Al4V), precipitate hardened stainless steel (17Cr-4Ni PH), X20Cr13 and X10CrNiMoV1222 steels. During incubation period as well as under prolonged testing, the HPDL surface treatment of these materials except for 17Cr-4Ni PH steel has enhanced the droplet erosion resistance significantly. This is due to increased hardness and formation of fine-grained martensitic phase due to rapid heating and cooling rates associated with laser treatment. The droplet erosion results of HPDL laser surface treatment of all these materials and their analysis form the main part of the article.

J Q Wang - One of the best experts on this subject based on the ideXlab platform.

  • short time oxidation of alloy 690 in high temperature and high Pressure Steam and water
    Journal of Materials Science & Technology, 2012
    Co-Authors: Fa Huang, J Q Wang, W Ke
    Abstract:

    The oxidation behavior of alloy 690 exposed to high-temperature and high-Pressure Steam and water at 280 degrees C for 1 h was investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). In high-temperature and high-Pressure Steam, the oxide film is composed of an outermost Ni-rich hydroxides layer, an intermediate layer of hydroxides and oxides enriched in Cr, an inner oxide layer. The film formed in high-temperature water is similar to that in Steam, except for missing the Ni-rich hydroxides layer. Samples with different surface finishes (electropolished, mechanically polished, ground, and as-received) were prepared for comparison. A general increase of the oxide thickness with the degree of surface roughness is observed. The equivalent oxide thicknesses lie in the range of 100-200 nm for the as-received samples, 150-250 nm for the samples ground to 400(#) and 10-20 nm for the samples ground to 1500(#), mechanically polished, and electropolished.

Haruo Nishida - One of the best experts on this subject based on the ideXlab platform.

  • Selective component degradation of oil palm empty fruit bunches (OPEFB) using high-Pressure Steam
    Biomass and Bioenergy, 2013
    Co-Authors: Azhari Samsu Baharuddin, Dong-hee Kim, Alawi Sulaiman, Mohd Noriznan Mokhtar, Minato Wakisaka, Mohd Ali Hassan, Yoshihito Shirai, Haruo Nishida
    Abstract:

    In order to accelerate the bioconversion process of press-shredded empty fruit bunches (EFB), the effect of high-Pressure Steam pre-treatment (HPST) in degrading the lignocellulosic structure was investigated. HPST was carried out under various sets of temperature/Pressure conditions such as 170/0.82, 190/1.32, 210/2.03, and 230°C/3.00MPa. It was noted that after HPST, the surface texture, color, and mechanical properties of the treated EFB had obviously altered. Scanning electron micrographs of the treated EFB exhibited effective surface erosion that had occurred along the structure. Moreover, the Fourier transform infrared and thermogravimetric analyses showed the removal of silica bodies and hemicellulose ingredients. X-ray diffraction profiles of the treated EFB indicated significant increases in crystallinity. These results reveal that HPST is an effective pre-treatment method for altering the physicochemical properties of the EFB and enhancing its biodegradability characteristics for the bioconversion process. © 2013 Elsevier Ltd.

  • physicochemical property changes of oil palm mesocarp fibers treated with high Pressure Steam
    Bioresources, 2012
    Co-Authors: Noor Seribainun Hidayah Md Yunos, Azhari Samsu Baharuddin, Khairul Faezah Md Yunos, Nazli M Naim, Haruo Nishida
    Abstract:

    High-Pressure Steam treatment (HPST) is a potential alternative method for the modification of lignocellulosic materials. The effect of HPST on oil palm mesocarp fibers (OPMF) was successfully investigated with treatment conditions of 170 oC/ 0.82 MPa, 190 oC/ 1.32 MPa, 210 oC/ 2.03 MPa, and 230 oC/ 3.00 MPa for 2 min. treatment time. Significant changes in the colour, smell, and mechanical properties of the samples were observed after the treatment. Scanning electron microscope (SEM) images revealed changes in the surface morphology of the OPMF after the pretreatment. The degradation of hemicelluloses and changes in the functional groups of the lignocellulosic components were identified using Fourier Transform Infrared (FTIR) and Thermogravimetric (TG) analysis. These results suggest that HPST is a promising method for the pretreatment of OPMF.