Zairyo-to-Kankyo
Online ISSN : 1881-9664
Print ISSN : 0917-0480
ISSN-L : 0917-0480
Search
Advanced search
OR
Browse
Search
Volume 64, Issue 4
Displaying 1-4 of 4 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Commentary
Review
  • Development of Environmentally Acceptable Technology for Cooling Water Treatment
    Shinichi Takasaki
    2015 Volume 64 Issue 4 Pages 114-120
    Published: April 15, 2015
    Released on J-STAGE: November 10, 2015
    DOIhttps://doi.org/10.3323/jcorr.64.114
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The technology of non-toxic corrosion inhibitors developed as a replacement of chromate in cooling water treatment was reviewed. Polyphosphate and phosphonate react with mother metal ion to form a protective film at anodic sites. On the other hand they form a protective film by precipitation with zinc ions and / or calcium ions at cathodic sites depending on their concentration. Acryl acid based polymer or maleic acid based polymer used as scale inhibitor enhances the effectiveness of cathodic inhibitors for carbon steel, and also made possible to increase the cycle number of concentration in cooling water and to decrease the total amount of phosphate in effluent water. The developments of green inhibitors, scale inhibitors for silica scale, non-chemical water treatment devices, and so on are expected in future.
    View full abstract
    Download PDF (1935K)
Research Paper
  • High-temperature Corrosion Behavior of Heat-resistant Cast Alloys in a Low-grade Fuel Firing Boiler Ash Environment
    Osamu Takahashi, Yuhua Su, Yo Tomota
    2015 Volume 64 Issue 4 Pages 132-138
    Published: April 15, 2015
    Released on J-STAGE: November 10, 2015
    DOIhttps://doi.org/10.3323/jcorr.64.132
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    In industrial boilers that use low-grade fuel, high-temperature sulfidation corrosion and vanadium attack have been major issues. High-temperature corrosion tests using actual boiler ash were performed for six heat-resistant cast alloys as candidate materials for burner chips and swirlers. At 850°C, corrosion was not sever, and SCH2 and 50Cr50Ni exhibited particularly good corrosion resistance. However, at 1050°C, corrosion weight loss of 50Cr50Ni, 30Cr70Ni, SCH13, and SCH22 dramatically increased, whereas that of 60Cr40Ni and Ni-less SCH2 was relatively small. Such corrosion mechanisms are discussed on the basis of microstructure observations and the results of EBSD and EDX analyses.
    View full abstract
    Download PDF (5088K)
  • Comparison of Photo Degradation Behavior of LDPE using Accelerated Weathering Instruments
    Takashi Miwa, Yukitoshi Takeshita, Yuichi Akage, Masamitsu Watanabe, M ...
    2015 Volume 64 Issue 4 Pages 139-144
    Published: April 15, 2015
    Released on J-STAGE: November 10, 2015
    DOIhttps://doi.org/10.3323/jcorr.64.139
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Samples of low-density polyethylene (LDPE) were photodegraded using accelerated weathering instruments and outdoor exposure. The physical properties and chemical structures of the photodegraded samples were studied through a tensile test, gel chromatography, and infrared spectroscopy. The molecular weight distribution of a photodegraded sample by using a fluorescent UV lamp at a high black panel temperature (80°C) was more similar to that of an outdoor-degraded sample than that of other artificially photodegraded samples by using a Xenon lamp at the standard black panel temperature (63°C). It is estimated that accelerated weathering tests at a high sample temperature could accelerate cross-linking than chain scission, consequently recreating molecule-enlargement similar to the outdoor-degraded sample.
    View full abstract
    Download PDF (2630K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top