S550Q a S620Q sú označenia pre konštrukčné oceľové plechy s vysokou výťažnosťou, ktoré sú súčasťou normy EN 10025-6, určené na dodanie po zušľachtení a popúšťaní (Q), poskytujúce vynikajúcu pevnosť, húževnatosť a zvárateľnosť pre náročné aplikácie ako ťažké stroje, žeriavy a mosty, kde 'S' znamená konštrukčné, číslo označuje minimálnu medzu klzu (550 MPa pre S550Q, 620 MPa pre S620Q) a 'Q' označuje tepelné spracovanie.
Chemické zloženie
|
S550QChemické zloženie |
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|
Stupeň |
Maximálny prvok (%) |
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|
C |
Si |
Mn |
P |
S |
N |
B |
Chróm |
|
|
S550 Q |
0.20 |
0.80 |
1.70 |
0.020-0.025 |
0.010-0.015 |
0.015 |
0.005 |
1.50 |
|
Meď |
Mo |
Nb |
Nie |
Ty |
V |
|
||
|
0.50 |
0.70 |
0.06 |
2.0 |
0.05 |
0.12 |
0.15 |
|
|
|
S620Q |
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|
C |
P |
S |
N |
B |
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|
S620 Q |
0.20 |
0.80 |
1.70 |
0.020-0.025 |
0.010-0.015 |
0.015 |
0.005 |
1.50 |
|
V |
|
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|
0.50 |
0.70 |
0.06 |
2.0 |
0.05 |
0.12 |
0.15 |
|
|
|
S620Q |
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|
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|
S620 Q |
-20 |
30J |
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|
3<> |
620 |
700-890 |
15 |
-20 |
30J |
|
|
50<> |
580 |
700-890 |
15 |
-20 |
30J |
|
|
100<> |
560 |
650-830 |
15 |
-20 |
30J |
|
|
S550Q |
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|
|
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|
S550 Q |
-20 |
30J |
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|
3<> |
550 |
640-820 |
16 |
-20 |
30J |
|
|
50<> |
530 |
640-820 |
16 |
-20 |
30J |
|
|
100<> |
490 |
590-770 |
16 |
-20 |
30J |
|
High Strength: Both offer superior yield and tensile strength, essential for load-bearing structures.
Quenched & Tempered (Q): This heat treatment process gives them their high strength and fine-grained microstructure.
Good Weldability & Toughness: Despite high strength, they maintain good ductility and impact toughness, even at low temperatures.
Applications: Used in heavy industry, construction, cranes, bridges, and offshore structures.
Naming Convention (EN 10025-6):
S: Structural steel.
550/620: Minimum yield strength in megapascals (MPa).
Q: Quenched and tempered delivery condition.
Think of them as tough, strong steel plates used when regular steel isn't strong enough, suitable for heavy-duty jobs where high stress and impact are expected. S620Q is stronger than S550Q.
