Corrosion Property Group

Aged deterioration due to corrosion of many social and industrial infrastructures constructed during the period of high economic growth are becoming serious problems year by year. In addition, with a diversification of metallic materials and usage environments, a variety of corrosion problems occurs. In corrosion property group, various corrosion deterioration behaviors of metallic materials exposed to different environments have been investigated in order to solve many corrosion problems. Furthermore, we aim to contribute to the improvement of the reliability and durability of metal materials under a wide range of environments through elucidation of their corrosion mechanisms.

Specialized Research Field

1. A new evaluation method of corrosion susceptibility using combined KFM-EBSD analyses

By analyzing the same field of view using a Kelvin Force Microscope (KFM) that detects the surface potential and an Electron Back Scattering Diffraction method (EBSD) that elucidates the crystal structure, it became possible to obtain not only electrochemical information of crack initiation based on potential difference but also crystallographic information of corrosion propagation. By using the combined KFM-EBSD analyses, we set two priority issues:
(1) Evaluation of corrosion resistance of innovative structural materials
(2) Multi-scale model analysis of corrosion initiation and propagation in joint welds
, and will contribute to the development of safe and secure structural materials for social implementation.



2. Development of corrosion protective coatings for magnesium alloys

Magnesium alloys attract attention as a lightweight material for transportation equipment and as a biodegradable material for stent and bone fixation devices. The practical use of Mg alloys does not show a significant progress due to the very low corrosion resistance regardless of the application field. We are therefore developing various corrosion protective coatings which show a suitable corrosion resistance depending on the application: from high corrosion resistant to bioabsorbable coatings. Calcium phosphate and polymer-calcium phosphate composite coatings are mainly examined.


3. Development of electrochemical surface treatments for improvement of corrosion resistance

In order to solve the problem of localized corrosion on stainless steel and zirconium in chloride-containing environments, we are elucidating the corrosion mechanism and developing novel electrochemical surface treatments for corrosion prevention. There are a lot of inclusions exposed on the surface of them, however, only limited inclusions can act as initiation site of corrosion. Selective removal of these inclusions by the electrochemical treatments realizes drastic improvement in corrosion resistance. It is expected to be applied to various products such as metallic biomaterials and structural materials.


4. Establishment of evaluation method for atmospheric corrosion property of steel materials and elucidation of corrosion mechanism

Appropriate repair and reinforcement are required for long-term reliability of steel infrastructures, and the understanding of corrosion property of steel materials in atmospheric environment leads to a selection of appropriate materials. In this study, monitoring technique of corrosion rate by the electrochemical impedance method is considered in order to establish the evaluation method for atmospheric corrosion property of steel materials. In addition, we aim to clarify the relationship between environmental factors and corrosion behavior by corrosion tests of steel materials in the chamber controlled temperature and relative humidity. 


Inquiry about this page

Corrosion Property Group
1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047 JAPAN
E-Mail: KATAYAMA.Hideki=nims.go.jp(Please change "=" to "@")