Low-Carbon, Age-Hardenable Steels for Use in Construction: A Review.

High-strength low-alloy HSLA steels are being used extensively in U.S. Naval shipbuilding and are being substituted for quenched and tempered HY-80 steel plate. This report examines other applications for the use of HSLA steels. They were studied to determine possible uses in U.S. Army Corps of Engineers construction projects, the current technology gaps, and the research necessary to fill those gaps. HSLA steels offer some benefits over conventional steels of the same strength level. They are virtually immune to hydrogen-assisted cracking in the heat affected zone of welds, which allows HSLA steel to be welded without preheating. However, at higher strength levels the weld metals used may require preheat to prevent weld metal hydrogen-assisted cracking. The low-carbon, fine grained microstructure that results from typical processing yields a favorable combination of excellent fabricability, strength, and toughness to HSLA steel that adds to its usefulness and gives it clear advantages over quenched and tempered construction steels. However, fatigue and buckling may limit direct design substitutions of HSLA steel in Corps new construction application. HSLA steel is resistant to hydrogen-assisted cracking but susceptible to reheat cracking, and applications requiring post weld heat treatment are not recommended. Also, local brittle zones may result in low toughness.