Difference between ABS DQ63 and CCS DQ63 steel plate

ABS DQ63 and CCS DQ63 are both extra-high-strength quenched and tempered steel plates specifically designed for the most demanding marine and offshore engineering 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 63 kgf/mm² strength class.

ABS Grade DQ63 is certified by the American Bureau of Shipping. The designation "DQ63" indicates a minimum yield strength of 620 MPa (90 ksi) and a tensile strength range of 720-890 MPa (104-129 ksi) . The "D" signifies the impact test temperature of -20°C (-4°F) , requiring minimum Charpy V-Notch impact energy of 46J (longitudinal average) . These plates are manufactured using quenched and tempered (QT) processes to achieve their exceptional combination of strength and toughness . Typical applications include offshore drilling platforms, shipbuilding, mobile offshore drilling units, and critical marine structures operating in cold environments .

CCS Grade DQ63 is certified by the China Classification Society and serves as the direct equivalent to ABS DQ63 in the Chinese classification system. According to classification society standards, CCS DQ63 shares identical mechanical property requirements with its ABS counterpart: minimum yield strength of 620 MPa . It belongs to the same product family as AQ63, DQ63, EQ63, and FQ63 series for shipbuilding and offshore applications, with each letter representing a different impact test temperature . Like ABS DQ63, CCS DQ63 requires Charpy impact testing at -20°C with similar energy requirements.

Key Differences:
The primary distinction between these two grades lies in their certifying authority and the corresponding quality control system . ABS DQ63 complies with American Bureau of Shipping rules and is recognized internationally, particularly in projects requiring ABS certification for offshore platforms and vessels destined for ABS-classed fleets . CCS DQ63 complies with China Classification Society rules and is typically specified for offshore structures built in Chinese shipyards or for projects under Chinese classification.

Chemical Composition

CCS DQ63 Extra high Strength Chemical Composition in Tempering and Quenching

Mechanical Property

CCS DQ63Extra high strength property in tempering and quenching