Steel Science Portal

Zairyo-to-Kankyo
New Arrival Alert : OFF

You can use this feature after you logged into the site.
Please click the button below.

Log in / Sign up
ONLINE ISSN: 1881-9664
PRINT ISSN: 0917-0480

Zairyo-to-Kankyo Vol. 59 (2010), No. 12

  • The Transmission of Technical Skill

    Shuhei Hayashi

    pp. 447-447

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.3323/jcorr.59.447

  • Life Cycle Management of Port Structures -V

    Kazuaki Zen

    pp. 448-451

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.3323/jcorr.59.448

    Abstract

    Cash flows are important in engineering economy since they form the basis for evaluating alternatives. The Present Worth (PW) method is popular because all future cash flows are converted into present dollars and makes it easy to determine the economic advantage of one alternative over another.
    The PW is determined by using the equation PW = FW(1+r)−N, where PW : present worth, FW : future worth, r : discount rate, N : compounding period. The factor (1+r)−N is known as the present worth factor. If discount rates remain constant at r% for the PW, FW, AW, all three values are equivalent. Hence, the AW and FW values can be easily computed for a project from the equivalent PW value.
    In this report, the relationship between the PW factors and time for different rates, the examples of equivalence calculation of the FW and AW values from the PW value, and the examples of the application of the PW method to port structures are shown.

  • Analysis of High Temperature Corrosion and Wear Damage on Furnace Water Wall in Pulverized Coal Firing Boiler

    Shoji Kyo, Masaharu Nakamori, Kazuya Kurokawa, Toshio Narita

    pp. 456-463

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.3323/jcorr.59.456

    Abstract

    Recently, a pulverized coal firing boiler is getting large capability; therefore, it should take a further effective environmental measure. As a facility aspect, it takes a measure to inhibit the amount of generation of NOx and, in operation aspect; it is operated by low O2 combustion. As a result, in the combustion chamber, it becomes to low O2 atmosphere because of lack of oxygen and also the sulfide corrosion becomes actualized because of H2S. In addition to that, it is recognized that it accelerates damages by multiple influences from erosion damage by steam blast from the wall blower to remove slag. The damage behavior around wall blower in the investigated boiler is as follows. (1) Steam erosion by direct collision of high temperature and high pressure steam. (2) The coal ash that was caught in the current of steam injection and collided on the tube surface causes the ash erosion. (3) The steam that is lower temperature than the tube temperature collides onto the tube surface which is exposed by high temperature combustion gas and that causes the thermal collision. The synergistic result of those 3 physical collisions causes a crack and delamination in the scale. Moreover, because of the above results, when the nascent metal aspect is exposed it is directly contacted with combustion gas. And that prompts the high temperature corrosion response and it is accumulated. For that result, it was concluded that the damage has been accelerated.

  • Increase in Corrosion Resistance of Stainless Steels by Passivation Treatment using (H2O2+O3) Solution

    Toshio Shibata

    pp. 464-467

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.3323/jcorr.59.464

    Abstract

    It is well known that nitric acid and nitric acid+chromate solution have been applied effectively for surface treatment or passivation treatment of stainless steels. However, recent regulation of waste water quality demands that nitrogen from nitric acid and Cr(VI) ion from chromic oxide have to be removed in the waste water. This study aims to develop alternate effective surface treatment method for passivation treatment of stainless steel. H2O2 and O3 might be candidate chemicals, because they decompose to oxygen and water after reaction which are non toxic to the environment. Effect of concentration of H2O2 and O3 and temperature on the treatment potential was examined. After the treatment, pitting potential was measured to evaluate corrosion resistance of passivated stainless steels. Passivation treatment condition using H2O2+O3 solution to increase pitting potential of SUS 304 and SUS 430 stainless steel was found.

  • Corrosion Products near the Shear Cut Edge of 55 mass% Al-Zn Alloy Coated Steel Sheets under Simulated Marine Atmospheric Environment

    Masamitsu Matsumoto, Nobuhiro Okada, Katsuhiro Nishihara, Masanari Kimoto, Takeo Kudo, Shinji Fujimoto

    pp. 468-477

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.3323/jcorr.59.468

    Abstract

    In order to characterize the corrosion products near the shear cut edge of the 55 mass% Al-Zn alloy coated steel sheet, galvanized steel sheets with scratch exposing substrate steel and galvanic couple electrodes composed of steel and Al-Zn alloy were subjected to atmospheric corrosion test using artificial seawater simulating the marine atmospheric environment. The corrosion products formed on Al-Zn coating, exposed steel and the coating near the exposed steel were analyzed by EDS, XRD and FT-IR. NaZn4(SO4)(OH)6Cl·6H2O, CaCO3 and Mg(OH)2 were identified on the exposed steel. Precipitation of these corrosion products was rationalized by thermodynamic analysis considering solubility products. Furthermore, it was concluded that the corrosion products exhibit a high electrical resistance to depress electrochemical reactions and also act as a barrier for oxygen diffusion, resulting in suppressed corrosion rate.

    Recommended Articles: Rate Controlling Process of Intermediate Phase Layers Growth in Hot Dip Galvanizing [ View more ]

    x

    Readers Who Read This Article Also Read

    1. Rate Controlling Process of Intermediate Phase Layers Growth in Hot Dip Galvanizing Tetsu-to-Hagané Vol.69(1983), No.1
    2. Corrosion Products of Hot-dip Zn-6%Al-3%Mg Coated Steel Sheet Subjected to Atmospheric Exposure Tetsu-to-Hagané Vol.89(2003), No.1
    3. Growth of Fe2Al5 Phase on Pure Iron Hot-Dipped in Al–Mg–Si Alloy Melt with Fe in Solution ISIJ International Vol.55(2015), No.7

  • Erratum : Temperature Dependency of External Stress Corrosion Crack Propagation of 304 Stainless Steel [Zairyo-to-Kankyo, Vol.59, No.11 p.430-435]

    Hitoshi Hayashibara, Masami Mayuzumi, Yoshihiro Mizutani, Jun-ichi Tani

    pp. 478-478

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.3323/jcorr.59.478

    Abstract

    [in Japanese]
  • © 2010 Japan Society of Corrosion Engineering

Article Access Ranking

24 Jul. (Last 30 Days)

  1. Perspective toward Long-term Global Goal for Carbon Dioxide Mitigation in Steel Industry Tetsu-to-Hagané Vol.105(2019), No.6
  2. Production and Technology of Iron and Steel in Japan during 2018 ISIJ International Vol.59(2019), No.6
  3. Preface to the Special Issue “Fundamentals and Application Technologies for High-performance Hot-dip Galvanized Coatings” Tetsu-to-Hagané Vol.105(2019), No.7
  4. Insights into Accumulation Behavior of Harmful Elements in Cohesive Zone with Reference to Its Influence on Coke ISIJ International Advance Publication
  5. Microstructure and Phase of Carbon Brick and Protective Layer of a 2800 m3 Industrial Blast Furnace Hearth ISIJ International Advance Publication
  6. Understanding the Structure and Structural Effects on the Properties of Blast Furnace Slag (BFS) ISIJ International Vol.59(2019), No.7
  7. Influence of Annealing Temperature and Dew Point on Kinetics of Mn External Oxidation Tetsu-to-Hagané Vol.105(2019), No.7
  8. Effect of Si/Mn Ratio on Galvannealing Behavior of Si-added Steel Tetsu-to-Hagané Vol.105(2019), No.7
  9. Properties-to-microstructure-to-processing Inverse Analysis for Steels via Machine Learning ISIJ International Advance Publication
  10. Quantitative Analyses of Chemical Structural Change and Gas Generation Profile of Coal upon Heating toward Gaining New Insights for Coal Pyrolysis Chemistry ISIJ International Advance Publication

Search Phrase Ranking

24 Jul. (Last 30 Days)

  1. blast furnace
  2. blast furnace productivity
  3. blast furnace permeability
  4. 龍角散
  5. chinese academy of science
  6. continuous casting
  7. corrosion
  8. ladle furnace
  9. oxygen coordination number of fe ions
  10. two-phase flow mathematical model of iron and slag liquid