The main difference between BV E690 and BV E620 steel plates lies in their strength levels, with the '690' indicating a higher minimum yield strength (around 690 MPa) than the '620' (around 620 MPa), both being high-strength low-alloy (HSLA) marine grade steels used in shipbuilding and offshore structures for demanding applications, but E690 offers superior load-bearing capacity.
Chemical Composition
|
BV E620 extra High Strength Chemical Composition Tempering and Quenching |
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|
Grade |
The Element Max (%) |
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|
C |
Si |
Mn |
P |
S |
Al(min) |
N |
|
|
BV E620 |
0.20 |
0.55 |
1.70 |
0.030 |
0.030 |
0.015 |
0.020 |
|
BV E690 extra High Strength Chemical Composition Tempering and Quenching |
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|
Grade |
The Element Max (%) |
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|
C |
Si |
Mn |
P |
S |
Al(min) |
N |
|
|
BV E690 |
0.20 |
0.55 |
1.70 |
0.030 |
0.030 |
0.015 |
0.020 |
Mechanical Property
|
BV E620 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 |
|
|
BV E620 |
Min Mpa |
Mpa |
Min % |
-40 |
J |
J |
|
620 |
720-890 |
15% |
41 |
62 |
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|
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal |
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|
BV E690 extra High strength property in Tempering and Quenching |
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|
Grade |
Mechanical Property |
Charpy V Impact Test |
||||
|
Yield |
Tensile |
Elongation |
Degree |
Energy 1 |
Energy 2 |
|
|
BV E690 |
Min Mpa |
Mpa |
Min % |
-40 |
J |
J |
|
690 |
770-940 |
14% |
46 |
69 |
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|
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal |
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Tensile Strength/Yield Strength: E690 has a higher minimum yield strength (approx. 690 MPa) compared to E620 (approx. 620 MPa).
Application: Both are for high-performance uses, but E690 is for even more critical areas needing greater strength in ships (hulls, decks) or offshore platforms.
Classification: Both fall under classification society Bureau Veritas (BV) standards for high-strength steels, often denoted with 'E' (for Engineering/Extra High Strength) and the strength level.
Chemical Composition: While similar in being HSLA, E690 might have slight adjustments in alloying elements (like Carbon, Manganese, Molybdenum, Nickel) to achieve its higher strength, though both share a balanced composition.
In essence, the "690" vs. "620" directly points to the higher load-bearing capability of the E690 grade for more critical, strength-intensive structural components.
