Super-Weathering Steel for Infrastructure Applications
The objective of this project was to develop new, low-cost steels with better weathering characteristics than those of presently used weathering steels. "Weathering" means that due to their chemical compositions, these steels exhibit increased resistance to atmospheric corrosion compared to unalloyed steels; a protective oxide layer forms on the steel surface under the influence of the weather. While the corrosion resistance is an important factor for steels, other factors should also be considered in the design of improved weathering steels. These factors include: mechanical properties such as strength, ductility and fracture resistance at low temperatures; ability of steel companies to produce the steel by existing steel-making processes; ease of steel-structure fabrication such as weldability and machinability; no adverse health effects during steel production and structures fabrication; and reasonable cost. Addition of the phosphorus and other elements to the A710 Grade B steel (developed previously at Northwestern University) and mitigation of the steel embrittlement by addition of specific amount of titanium to keep phosphorous from migration to the grain boundaries was the approach taken in this project. As a result, four steels were designed and tested. The steels were very ductile and fracture-tough to -100°F, thus significantly outperforming the requirements of ASTM A709 bridge steel standard. No brittle heat-affected zone was formed as result of high-power laser welding simulation, thus indicating that the steels could be easily welded without pre- or post-welding heat-treatment. The accelerated studies indicated that developed steels have better weathering characteristics than A588 weathering steels that are currently used for bridge construction. The production of the newly developed steels does not require special processing or thermal treatment; therefore, these steels can be produced by any steel manufacturer in any steel-plate sizes.
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Supplemental Notes:
- This Highway IDEA project was conducted by Northwestern University, Evanston,Illinois. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
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Authors:
- Vaynamn, Semyon
- Fine, Morris E
- Chung, Yip-Wah
- Publication Date: 2014-1
Language
- English
Media Info
- Media Type: Web
- Edition: Final Report
- Features: Figures; Photos; References; Tables;
- Pagination: 21p
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Serial:
- NCHRP-IDEA Program Project Final Report
- Publisher: Transportation Research Board
Subject/Index Terms
- TRT Terms: Corrosion resistance; Phosphorus; Steel bridges; Structural steel; Weathering; Weathering steel
- Identifier Terms: Innovations Deserving Exploratory Analysis (IDEA) (Program)
- Subject Areas: Design; Highways; Materials; I34: Steels and Metals;
Filing Info
- Accession Number: 01530622
- Record Type: Publication
- Report/Paper Numbers: Highway IDEA Project 160
- Files: TRIS, TRB, ATRI
- Created Date: Jul 22 2014 12:49PM