| Abstract Scope |
High-strength low-alloy (HSLA) steels are used in applications such as pressure vessels, piping and tubing, and structural components where it is important that they maintain high mechanical properties. This study investigated the effect of normalization heat treatment on several HSLA grades produced at Steel Dynamics Inc., with a focus on a Nb–V microalloyed grade designed for 65 ksi yield strength. Samples were heated at 1150–1650°F in 100°F increments and held for one hour, then air cooled to evaluate mechanical properties and microstructural evolution. Tensile Testing showed peak strength near 1150°F due to retained bainite and vanadium carbide precipitation, followed by progressive strength loss and ductility increase as carbides dissolved and grains coarsened. Uniform toughness was observed around 1450°F showcasing eliminated rolling direction effects. These show how heat treatment effects strength, ductility, and rolling in HSLA steels and provide insight into industrial processing windows for optimization. |