High yield strength S690Q, S690QL, S690QL1 steel

S690 steel is the European standard quenched and tempered high yield strength structural steel. S stands for structural steel, Q stands for delivery conditions, 690 is the yield value, in MPa.

S690Q, S690QL, S690QL1 steel plate chemical composition (analysis of finished products):

C

Si

Mn

P

S

Ni

Cr

Mo

Cu

Nb

V

Ti

N

Zr

B

≤0.2

≤0.8

≤1.7

≤0.025

≤0.015

≤2

≤1.5

≤0.7

≤0.5

≤0.06

≤0.12

≤0.05

≤0.015

≤0.15

≤0.005

Mechanical properties, yield tensile strength of S690Q, S690QL, S690QL1 steel:
S690Q, S690QL, S690QL1 steel plate thickness 3-50mm
ReH(MPa)≥690
Rm(MPa)770-940
A(%)≥14
Akv(J)≥30 longitudinal;
Horizontal: Akv≥27J

S690Q, S690QL, S690QL1 steel plate thickness>50-100mm
ReH(MPa)≥650
Rm(MPa)760-930
A(%)≥14
Akv(J)≥30 longitudinal;
Horizontal: Akv≥27J

S690Q, S690QL, S690QL1 steel plate thickness>100-150mm
ReH(MPa)≥630
Rm(MPa)710-900
A(%)≥14
Akv(J)≥30 longitudinal;
Horizontal: Akv≥27J
S690QL1 impact temperature -60℃; S690QL impact temperature -40℃; S690Q impact temperature -20℃.

S690Q, S690QL, S690QL1 steel plate production process:
1. Raw materials (scrap steel, pig iron and molten iron)
2. Electric furnace (100-ton electric arc furnace smelting), converter
3. LF furnace molten steel refining treatment
4. Vacuum treatment of molten steel in VD or VOD furnace
5. Die casting (a variety of key-type die casting lines) or continuous casting (large slab continuous casting machine); (one ingot remelting 50 tons slab type electroslag furnace)
6. Heating (continuous furnace and soaking furnace)
7. Steel plate rolling (4100 and 4200mm mills)
8. Heat treatment of steel plate (normalizing and tempering)
9. Steel plate cutting inspection
10. Storage