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Federal Highway Administration Research and Technology
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|This report is an archived publication and may contain dated technical, contact, and link information|
|Publication Number: FHWA-HRT-11-061 Date: July 2011|
Publication Number: FHWA-HRT-11-061
Date: July 2011
Improved Corrosion-Resistant Steel for Highway Bridge Construction
FHWA Contact: Paul Virmani, HRDI-60, (202) 493-3052,
This document is a technical summary of the Federal Highway Administration report,
Figure 1. Graph. Average Charpy V-notch absorbed energy values for experimental steels tempered to achieve yield strength greater than 50 ksi (344.5 MPa).
This bar graph shows the average Charpy V-notch (CVN) absorbed energy values for experimental steels tempered to achieve a yield strength (YS) greater than 50 ksi (344.5 MPa). CVN is plotted on the y-axis ranging from 0 to 180 ft-lb (0 to 24.9 m-kg) in increments of 20 ft-lb (2.7 m-kg). Test temperature in Fahrenheit is on the x-axis with four test temperatures: 70, 40, 10, and -10 ºF (21.11, 4.44, -12.22, and -23.33 ºC). In the 10 ºF (-12.22 ºC) portion, there are two horizontal lines: one at 30 ft-lb (4.15 m-kg) designated fracture critical (FC) and one at 20 ft-lb (2.77 m-kg) designated nonfracture-critical (NFC). Different colored bars at each test temperature represent steels 11Cr, 9Cr, 9Cr2Si, 7Cr2Si, 7Cr2Al, and 5Cr2Si2Al. At all temperatures, the bar for steel 11Cr is significantly higher than any of the other steels. At 70 ºF (21.11ºC), the 11Cr bar is 154 ft-lb (21.3 m-kg), the 9Cr bar is 61 ft-lb (8.43 m-kg), the 9Cr2Si bar is 46 ft-lb (6.36 m-kg), and the 7Cr2Si bar is 34 ft-lb (4.70 m-kg). The bars for 7Cr2Al and 5Cr2Si2Al are short at 4 and 3 ft-lb (0.55 and 0.41 m-kg), respectively. At 40 ºF (4.44 ºC), the 11Cr bar is 118 ft-lb (16.32 m-kg), the 9Cr2Si bar is 32 ft-lb (4.43 m-kg), the 7Cr2Si bar is 19 ft-lb (2.63 m-kg), and the 9Cr bar is 7 ft-lb (0.97 m-kg). There are no data for the 7Cr2Al or 5Cr2Si2Al steels at 40, 10, and -10 ºF (4.44, -12.22, and -23.33 ºC). At 10 ºF (-12.22 ºC), the 11Cr bar is 109 ft-lb (15.07 m-kg), and the 9Cr, 9Cr2Si, and 7Cr2Si bars are between 3 and 8 ft-lb (0.41 and 1.11 m-kg). At -10 ºF (-23.33 ºC), the 11Cr bar is the only one shown at 85 ft-lb (11.76 m-kg).
Figure 2. Graph. Summary of 5 percent NaCl cyclic corrosion test results.
This bar graph provides a summary of 5 percent sodium chloride (NaCl) results. Thickness loss is plotted on the y-axis ranging from 0 to 60 mil (0 to 1,524 microns) in increments of 10 mil (254 microns). Cyclic corrosion cycles is plotted on the x-axis ranging from 0 to 100 cycles in increments of 20 cycles. Eight data series are plotted, each with a distinctive symbol and color, representing the steels under study. All the lines are approximately linear and begin at the bottom left upward to the right. The highest line is labeled A588, and it reaches 52.4 mil (1,330.96 microns) after 100 cycles. The next highest line is labeled 7Cr2Si, and it reaches 31.3 mil (795.02 microns) after 100 cycles. The next highest line is labeled 5Cr2Si2Al, and it reaches 28.1 mil (713.74 microns) after 100 cycles. The fourth highest line is labeled 9Cr2Si, and it reaches 21.7 mil (551.18 microns) in 100 cycles. The fifth and sixth highest lines are coincident and are labeled 7Cr2Al and 9Cr. They reach 15.2 and 14.8 mil (386.08 and 375.92 microns) after 100 cycles. The lowest lines are essentially coincident, and they are labeled 11Cr and A1010. They reach only 6.5 and 4.7 mil (165.1 and 119.38 microns) after 100 cycles.