HSLA-80 Steel
HSLA-80 (High-Strength Low-Alloy 80) is an age-hardening Ni-Cu-Cr-Mo alloy steel plate developed as a weldable, high-toughness alternative to HY-80 for naval hull and structural applications. With a minimum yield strength of 80,000 psi and excellent low-temperature Charpy impact toughness, HSLA-80 is used for ship hulls, submarine pressure hull sections, and marine structural components where the combination of strength, toughness, and weldability without preheat is essential.
Unlike quench-and-tempered steels such as HY-80, HSLA80 achieves its properties through precipitation hardening, which allows welding without preheat in most plate thicknesses and substantially reduces weld cracking risk. Its controlled composition also makes it suitable for high heat-input welding processes used in large-scale naval construction.
Product Forms & Size Range of HSLA-80 Steel
HSLA80 plate per MIL-S-24645 Grade A is available in thicknesses from 0.25″ to 2.50″ (6.4–63.5 mm) and widths up to 144″. Supplied as-rolled or controlled-rolled with minimum 80 ksi (552 MPa) yield and 90–110 ksi tensile strength. Charpy V-notch toughness is specified at −60°F (−51°C) for naval structural applications.
STRENGTH PROPERTIES OF HSLA-80 STEEL
HSLA-80 achieves its strength through precipitation of fine copper-rich particles during aging — no post-rolling quench is required. Minimum yield strength: 80,000 psi (552 MPa). Minimum tensile strength: 90,000 psi (621 MPa). Minimum elongation: 18%. Low-temperature CVN impact: ≥60 ft-lb at −60°F. Weldability with high heat input (>100 kJ/in) is significantly better than HY-80 in equivalent thicknesses.
HSLA-100 Steel
Higher-strength companion grade with 100 ksi minimum yield — used where HSLA-80 strength is insufficient for thicker structural sections.
HY-80 Steel
Quench-and-tempered naval steel with 80 ksi yield — the predecessor to HSLA-80, requiring preheat for welding in thicker sections.
Certified Material for Critical Service
HSLA-80 steel is supplied to MIL-S-24645 Grade A. Mill test reports document heat chemistry, mechanical properties (yield, tensile, elongation, reduction in area), and Charpy V-notch impact test results at −60°F. Material is approved for naval ship construction under NAVSEA authorization programs.