Difference between ABS DQ51 and ABS DQ63 steel plate

ABS DQ51 is an extra-high-strength marine steel plate certified by the American Bureau of Shipping (ABS) , produced through quenching and tempering (Q&T) . The "D" grade signifies it is impact tested at -20°C . It has a minimum yield strength of 500 MPa and tensile strength ranging from 610 to 770 MPa, with minimum elongation of 16% . Impact energy requirements are minimum 50J (longitudinal) or 33J (transverse) at -20°C . This grade is widely used in offshore drilling platforms, shipbuilding, and marine structures requiring high strength and toughness .

ABS DQ63 is an ultra-high-strength marine steel plate also certified by ABS, produced through quenching and tempering (Q&T) . The "63" denotes a minimum yield strength of 620 MPa and tensile strength ranging from 720 to 890 MPa, with minimum elongation of 15-17% . Impact testing is performed at -20°C, with minimum energy requirements of 62J (longitudinal) or 41J (transverse) . This grade is designed for critical offshore structures, including drilling platforms and marine engineering projects .

Both ABS DQ51 and ABS DQ63 are ABS-certified, quenched and tempered ultra-high-strength marine steels with excellent toughness tested at -20°C, ensuring reliable performance in harsh marine environments . Their primary difference lies in strength level: DQ51 offers a minimum yield strength of 500 MPa with tensile strength of 610-770 MPa, suitable for high-strength offshore platforms and shipbuilding, while DQ63 provides a substantially higher minimum yield strength of 620 MPa with tensile strength reaching 720-890 MPa, designed for the most demanding load-bearing applications requiring maximum strength-to-weight ratio. Both grades maintain good weldability and are essential for critical marine structural applications.

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