ABS DQ63 and DQ70 are high-strength, quenched and tempered (QT) steel plates certified by the American Bureau of Shipping (ABS) for critical marine and offshore applications, offering minimum yield strengths of 620 MPa and 690 MPa respectively. They are used in shipbuilding, offshore rigs, and marine engineering requiring high toughness and good weldability.
Chemical Composition
|
ABS DQ70 Extra high Strength Chemical Composition in Tempering and Quenching |
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Grade |
The Element Max (%) |
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|
C |
Si |
Mn |
P |
S |
N |
|
|
ABS DQ70 |
0.20 |
0.55 |
1.7 |
0.030 |
0.030 |
0.02 |
|
ABS DQ63 Extra high Strength Chemical Composition in Tempering and Quenching |
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|
Grade |
The Element Max (%) |
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|
C |
Si |
Mn |
P |
S |
N |
|
|
ABS DQ63 |
0.20 |
0.55 |
1.7 |
0.030 |
0.030 |
0.02 |
Mechanical Property
|
ABS DQ70 Extra high strength property in tempering and quenching |
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|
Grade |
Mechanical Property |
Charpy V Impact Test |
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|
Yield |
Tensile |
Elongation |
Degree |
Energy 1 |
Energy 2 |
|
|
Min Mpa |
Mpa |
Min % |
-20 |
J |
J |
|
|
ABS DQ70 |
690 |
770-940 |
14 |
41 |
62 |
|
|
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal |
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|
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 |
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Key Characteristics and Applications
ABS DQ63: A high-strength, Quenched and Tempered (QT) grade, typically featuring a minimum yield strength of 620 MPa. It is designed for structures with high load-bearing requirements, such as offshore drilling platforms and ship hulls.
ABS DQ70: An ultra-high-strength, Quenched and Tempered (QT) grade, generally offering a minimum yield strength. This grade is employed in high-stress components of offshore structures and specialized shipbuilding projects.
Impact Toughness: The 'D' in DQ63/DQ70 indicates that the steel passes Charpy V-notch impact tests at a specific low temperature, making them suitable for cold-environment, offshore applications.
Fabrication: These materials are produced through quenching and tempering to achieve high strength while maintaining toughness and weldability, crucial for heavy marine structures.
