Elevated Temperature Properties of A588 Weathering Steel

In recent decades, bridge fires have become a major concern in the United States. Fire hazard in bridges can result in significant economic and public losses. New construction of bridges often use “Weathering Steel” (also known as “Corten Steel”), which has a corrosion-retarding effect since the steel forms a protective rust layer on its surface under the influence of the weather. To date, no information exists on the high temperature mechanical properties of weathering steel. The objective of this work is to develop a database of mechanical properties of A588 weathering steel that has been exposed to high temperatures. These properties include the residual (after heating and cooling) stress-strain, fracture toughness, and surface hardness. The parameters that are investigated include temperature (800°F, 1000°F, 1200°F, and 1500°F), cooling methods (in air (CIA), and in water (CIW), representing fire-fighting effects), and material. Experiments are also done in a steady-state elevated temperature condition. A comparison is made between A588 weathering steel, used widely for bridges, and another material whose chemical composition and mechanical properties allows it to be classified by ASTM as both an older weathering steel (A242), a steel commonly used in building construction (A992), and also a non-weathering steel used for bridges (A709 Grade 50). The studies showed that at temperatures of 1200°F and below, the residual material properties of both materials studied (representing the post-fire condition), were affected no more than on the order of 10% compared to the unheated steel. Examining the residual properties of the CIW specimens, there is a clear trend of decreasing fracture toughness with increasing temperature. There is also a clear trend of increasing hardness with increasing temperature. It is expected that the CIW method produces different microstructure changes than the CIA method, thus resulting in the trends observed. Specimens tested to 1500°F showed a significant change in response, especially for the CIW method of cooling. At this temperature, it is likely that the steel has gone through a phase change. Practically speaking, a bridge that reaches 1500°F will experience significant permanent deformations if this temperature is widespread and in that case it will likely need to be demolished. Based on the results obtained thus far, it is likely that if significant permanent deformations are not observed, a bridge of A588 weathering steel has the potential to be put back into service following a fire.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 35p

Subject/Index Terms

Filing Info

  • Accession Number: 01523320
  • Record Type: Publication
  • Report/Paper Numbers: CAIT-UTC-021
  • Contract Numbers: DTRT12-G-UTC16/155-6181
  • Created Date: Apr 25 2014 4:12PM