The difference between S355G9+M and S355G9+N steel plate is that the delivery status is different.
S355G9+M and S355G9+N European standard high-strength structural steel are welded structural steel for fixing offshore structures.
"S" indicates structural steel,
"355" indicates the minimum yield strength of steel plate,
G9 indicates the relevant number of steel grade characteristics,
M is hot rolled or TMCP, N is normalized, normalized rolled.
S355G9+M, S355G9+N steel plate executive standard: EN 10225-2009
Analysis of chemical composition of S355G9+M steel plate (finished products):
| Grade | C | Si | Mn | P | S | Ni | Cr | Mo |
| S355G9+M | ≤0.12 | 0.15-0.55 | ≤1.65 | ≤0.02 | ≤0.010 | ≤0.7 | ≤0.2 | ≤0.08 |
| Cu | Nb | V | Ti | Alt | N | B | Ca | Pb |
| ≤0.3 | ≤0.03 | ≤0.06 | ≤0.025 | 0.015-0.055 | ≤0.010 | ≤0.0005 | ≤0.005 | ≤0.010 |
Chemical composition of S355G9+N steel plate (melting analysis):
| Grade | C | Si | Mn | P | S | Ni | Cr | Mo | Cu |
| S355G9+N | ≤0.12 | 0.15-0.55 | ≤1.65 | ≤0.02 | ≤0.010 | ≤0.7 | ≤0.2 | ≤0.08 | ≤0.3 |
| Nb | V | Ti | Alt | N | B | Ca | Pb | Ceq Max | Pcm Max |
| ≤0.03 | ≤0.06 | ≤0.025 | 0.015-0.055 | ≤0.010 | ≤0.0005 | ≤0.005 | ≤0.010 | ≤0.43 | ≤0.22 |
Composition Notes:
As, Sn, Pb, Bi, Ca, B are residual elements;
Nb+V≤0.06; Nb+V+Ti≤0.08; Alt/N≥2; As≤0.03; Sn≤0.02; Bi≤0.01;
Thickness>75mm, when the delivery condition is thermomechanical rolling, Mo≤0.2;
Thickness>40mm, Ni≥0.3.
