What is the difference between cold-rolled and hot-rolled SPA-H weathering steel plate in terms of mechanicalproperties?

Jan 21, 2026 Leave a message

Mechanical Property Differences Between Cold-Rolled and Hot-Rolled SPA-H Weathering Steel Plate

The core difference stems from cold rolling-induced work hardening (room-temperature plastic deformation) of cold-rolled SPA-H, which enhances strength/hardness but reduces ductility, while hot-rolled SPA-H maintains a balanced, unhardened microstructure with better formability-both meet JIS G 3125 basic mechanical requirements, with cold-rolled limited to 1.6–6 mm gauges and hot-rolled covering all commercial thicknesses (1.6–100 mm).

info-609-368

Yield Strength: Cold-rolled = 415–450 MPa (20–30% higher than hot-rolled); Hot-rolled = 345–420 MPa (JIS min 345 MPa).

Tensile Strength: Cold-rolled = 550–600 MPa (15–25% higher than hot-rolled); Hot-rolled = 480–620 MPa (JIS min 480 MPa).

Brinell Hardness: Cold-rolled = 210–270 HBW (15–25% higher than hot-rolled); Hot-rolled = 180–220 HBW.

Elongation at Break: Cold-rolled = ≤15% (significant drop, poor formability); Hot-rolled = ≥20% (good ductility for shaping).

Toughness: Cold-rolled has slightly reduced low-temperature toughness; Hot-rolled maintains stable ambient/low-temperature impact toughness (40–50 J room-temperature Charpy V-notch).

Residual Stress: Cold-rolled has high internal residual stress (from work hardening); Hot-rolled has low, dispersed residual stress (no severe work hardening).

info-457-457