Electrochemical surface potential and mass loss corrosion investigation of improved corrosion resistant steels for highway bridge construction.

详细信息   

• 作者：Conrad ; Megan B.
• 学历：Master
• 年：2009
• 导师：Roberts, James E.,eadvisor
• 毕业院校：Lehigh University
• Department：Chemistry
• ISBN：9781109121209
• CBH：1463946
• Country：USA
• 语种：English
• FileSize：10145197
• Pages：91

文摘

In 2007, the Federal Highway Administration initiated a program to develop an improved corrosion resistant steel for highway bridge construction. The ATLSS Center Advanced Technology for Large Structural Systems) at Lehigh University in Bethlehem, PA was contracted to implement a series of investigations to develop copper-nickel precipitation-strengthened weathering steels with similar or improved weldability and toughness to high performance grade steels as well as enhanced corrosion resistance without the need of protective coating systems. The corrosion properties of the developmental steels were investigated based on electrochemical surface potential and mass loss measurements after exposure of the alloys to accelerated cyclic corrosion protocols in order to discover the effects of elemental additions on the corrosion-products of weathering steel such that a new improved steel composition for highway bridges can be proposed. Taking into account the results compiled from electrochemical corrosion studies on the bare steel samples, mass loss corrosion determinations based on chemical stripping of the corrosion product which accumulated on the coupons after exposure to accelerated cyclic corrosion protocols both spray and immersion) in 5% sodium chloride electrolyte solution, and visual rust morphology observations, it was determined that enhanced levels of copper and nickel have the most beneficial effect on the corrosion properties of the steel. Similarly, copper and nickel are the only elemental additions to the experimental alloys that effectively reduce the corrosion rate of the steel in both the electrochemical and mass loss corrosion studies as determined from multivariable regression statistical analyses. Therefore, increasing the copper and nickel content should have the most favorable effect on the corrosion properties of weathering steel. According to this conclusion, developmental Steels M and D, which both have the highest copper and nickel content, show the most promise for utilization in highway bridge construction as determined from this study.