(1) High strength: in general its yield strength above 300MPa.
(2) high toughness: Requirements elongation rate of 15% to 20%, impact toughness at room temperature is greater than 600kJ / m ~ 800kJ / m. For large welded components, also requires a high fracture toughness.
(3) good weldability and cold forming properties.
(4) Low cold-brittle transition temperature.
(5) good corrosion resistance.