Difference between ABS EQ47 and ABS EQ63 steel plate

ABS EQ47 is an extra-high-strength marine steel plate certified by the American Bureau of Shipping (ABS) . The "E" designation signifies it is impact tested at -40°C, ensuring excellent low-temperature toughness for demanding marine environments . It has a minimum yield strength of 460 MPa (67 ksi) and tensile strength ranging from 570 to 720 MPa (83-104 ksi), with minimum elongation of 17% . Impact energy requirements are minimum 46J (longitudinal) or 31J (transverse) at -40°C . This grade is produced through thermo-mechanical controlled processing (TMCP) and is widely used in offshore drilling platforms, shipbuilding, and critical marine structures.

ABS EQ63 is an ultra-high-strength marine steel plate also certified by ABS with impact toughness tested at -40°C . The "63" denotes a minimum yield strength of 620 MPa (90 ksi) and tensile strength ranging from 720 to 890 MPa (104-129 ksi), with minimum elongation of 15% . Impact energy requirements are minimum 62J (longitudinal) or 41J (transverse) at -40°C . The chemical composition features carbon ≤0.20% and manganese ≤1.70% . This grade is manufactured using quenching and tempering (Q&T) processes and is designed for the most demanding offshore structures, including drilling platforms, jack-up rig legs, and floating production storage vessels (FPSOs).

Both ABS EQ47 and ABS EQ63 are ABS-certified high-strength marine steels with excellent low-temperature toughness tested at -40°C, ensuring reliable performance in harsh marine environments . Their primary difference lies in strength level: EQ47 offers a minimum yield strength of 460 MPa with tensile strength of 570-720 MPa, suitable for high-strength offshore platforms and shipbuilding , while EQ63 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 . Additionally, EQ47 is typically produced using TMCP , whereas EQ63 requires more advanced processing like quenching and tempering (Q&T) to achieve its enhanced mechanical properties. Both grades feature controlled chemical composition and maintain good weldability for critical marine structural applications.

Chemical Composition

Mechanical Property