Difference between ABS DQ70 and CCS DQ70 steel plate

ABS DQ70 and CCS DQ70 are both extra-high-strength quenched and tempered steel plates specifically engineered for the most demanding marine and offshore applications . They are certified by two major classification societies-ABS (American Bureau of Shipping) and CCS (China Classification Society)-and represent the higher toughness tier within the 70 kgf/mm² strength class, designed for structures operating in cold environments.

ABS Grade DQ70 is certified by the American Bureau of Shipping. The designation "DQ70" indicates a minimum yield strength of 690 MPa (100 ksi) and a tensile strength range of 770-940 MPa (112-136 ksi) . The "D" signifies the Charpy V-notch impact test temperature of -20°C (-4°F) , requiring minimum average energy of 41J (transverse) or 62J (longitudinal) . These plates are manufactured using quenched and tempered (QT) processes to achieve their exceptional combination of strength and toughness . Typical applications include offshore drilling rigs, platforms, jack-up rig legs, ship hulls, and critical marine structures requiring superior strength and durability in harsh environments .

CCS Grade DQ70 is certified by the China Classification Society and serves as the direct equivalent to ABS DQ70 in the Chinese classification system . According to classification society standards, CCS DQ70 shares identical mechanical property requirements with its ABS counterpart: minimum yield strength of 690 MPa . It belongs to the same product family as AQ70, DQ70, EQ70, and FQ70 series for shipbuilding and offshore applications, with each letter representing a different impact test temperature . Like ABS DQ70, CCS DQ70 requires Charpy impact testing at -20°C with similar energy requirements.

Chemical Composition

Mechanical Property