High-strength high-performance plate steel with low yield-tensile ratio
- U.S. Steel Technical Center, Monroeville, PA (United States)
In an effort to develop a high-strength, high performance plate steel with a low yield-tensile ratio, 2-inch-thick plates of three modified low carbon, low-sulfur, A514 Grade F (USS ``T-1``) steels were evaluated in various rolling and heat-treatment conditions. Several of the processing conditions investigated resulted in plates meeting the AASHTO Zone 3 (cold region) Grade 100 (100-ksi minimum yield strength) minimum toughness requirement of 35 ft-lb average at {minus}30 F. The best steel/process overall was the 0.11C-0.04V steel given a standard hot-rolling treatment followed by air cooling (HR-AC), then quenching and tempering (at 1,250 F). Conventional controlled rolling followed by air cooling (CCR-AC), then quenching and tempering, was more beneficial to the V-Cb steel than to the two V steels. Controlled rolling and air cooling before quenching and tempering (for the same tempering temperature) promoted a slight increase in yield strength in these martensitic steels, the average increase being about 4 ksi. However, the yield-tensile ratios of all the controlled-rolled plates were generally higher than those of the corresponding hot-rolled plates. Acceptably low yield-tensile ratios could be achieved from intercritical heating/holding treatments interspersed between the quenching and tempering treatments; but the yield strength of each plate was below the desired 100 ksi minimum. More work is needed to achieve a (possibly impractical) goal of 100-ksi minimum yield strength with a yield tensile ratio under about 0.85. Technical reviews of this goal/requirement by appropriate specification committees have been initiated.
- OSTI ID:
- 234235
- Report Number(s):
- CONF-951026--; ISBN 0-87170-555-9
- Country of Publication:
- United States
- Language:
- English
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