ABS EQ63 and DQ63 are both high-strength, quenched and tempered steel plates for marine/offshore use with 630 MPa yield strength, but the main difference is their impact toughness temperature requirement: 'Q' (DQ63) denotes a lower test temperature (more toughness for cold environments) than 'E' (EQ63), though both meet specific ABS toughness standards, with 'Q' usually meaning tougher at lower temps, making EQ63 good for general offshore, while DQ63 is better for colder conditions.
Chemical Composition
|
ABS EQ63 Extra high Strength Chemical Composition in Tempering and Quenching |
||||||
|
Grade |
The Element Max (%) |
|||||
|
C |
Si |
Mn |
P |
S |
N |
|
|
ABS EQ63 |
0.20 |
0.55 |
1.7 |
0.030 |
0.030 |
0.02 |
|
ABS DQ63 Extra high Strength Chemical Composition in Tempering and Quenching |
||||||
|
Grade |
The Element Max (%) |
|||||
|
C |
Si |
Mn |
P |
S |
N |
|
|
AB/DQ63 |
0.20 |
0.55 |
1.7 |
0.030 |
0.030 |
0.02 |
Mechanical Property
|
ABS EQ63 Extra high strength property in tempering and quenching |
||||||
|
Grade |
Mechanical Property |
Charpy V Impact Test |
||||
|
Yield |
Tensile |
Elongation |
Degree |
Energy 1 |
Energy 2 |
|
|
Min Mpa |
Mpa |
Min % |
-40 |
J |
J |
|
|
ABS EQ63 |
620 |
720-890 |
15 |
41 |
62 |
|
|
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal |
||||||
|
ABS DQ63Extra high strength property in tempering and quenching |
||||||
|
Grade |
Mechanical Property |
Charpy V Impact Test |
||||
|
Yield |
Tensile |
Elongation |
Degree |
Energy 1 |
Energy 2 |
|
|
Min Mpa |
Mpa |
Min % |
-20 |
J |
J |
|
|
AB/DQ63 |
620 |
720-890 |
15 |
41 |
62 |
|
|
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal |
||||||
Key Similarities:
ABS Grades: Both are certified by the American Bureau of Shipping (ABS) for shipbuilding and offshore structures.
Strength: Both have a minimum yield strength of 630 MPa (90 ksi).
Processing: Both are quenched and tempered (Q&T) for high strength and toughness.
Key Difference (The Letter):
D (DQ63): Denotes a standard toughness requirement, often associated with colder water applications where impact resistance at lower temperatures is crucial.
E (EQ63): Denotes a higher impact toughness requirement (or specific test condition) than basic grades, suitable for general offshore use, but 'D' usually implies better low-temp performance.
