S275N and S420N are EN 10025 normalized structural steels, differing primarily in strength: S275N offers a minimum yield strength of 275 MPa, good for general fabrication in colder conditions, while S420N is a higher-strength grade with a minimum yield of 420 MPa, suited for heavy-duty, welded structures needing better performance at low temperatures, though with higher cost and potentially less availability. S420N is stronger, tougher, and designed for more demanding applications than S275N, which is a more common, lower-strength choice.
Chemical Composition of S275N Steel Plate
|
Element |
Symbol |
Min (%) |
Max (%) |
|---|---|---|---|
|
Carbon |
C |
- |
0.20 |
|
Silicon |
Si |
- |
0.40 |
|
Manganese |
Mn |
0.80 |
1.60 |
|
Nickel |
Ni |
- |
0.80 |
|
Phosphorus |
P |
- |
0.035 |
|
Sulfur |
S |
- |
0.030 |
|
Chromium |
Cr |
- |
0.30 |
|
Molybdenum |
Mo |
- |
0.10 |
|
Vanadium |
V |
- |
0.05 |
|
Nitrogen |
N |
- |
0.012 |
|
Niobium |
Nb |
- |
0.050 |
|
Titanium |
Ti |
- |
0.050 |
|
Aluminum |
Al |
0.020 |
- |
|
Copper |
Cu |
- |
0.35 |
|
CEV |
- |
- |
0.40 |
Chemical Composition of S420N Steel Plate
|
Element |
Ladle Analysis (max %) |
Product Analysis (max %) |
|---|---|---|
|
Carbon (C) |
0.20 |
0.23 |
|
Silicon (Si) |
0.60 |
0.70 |
|
Manganese (Mn) |
1.00-1.70 |
1.10-1.80 |
|
Phosphorus (P) |
0.025 |
0.035 |
|
Sulfur (S) |
0.015 |
0.025 |
|
Nitrogen (N) |
0.025 |
0.030 |
|
Aluminum (Al) |
0.020 (min, total) |
0.020 (min, total) |
|
Niobium (Nb) |
0.05 |
0.06 |
|
Vanadium (V) |
0.10 |
0.12 |
|
Titanium (Ti) |
0.05 |
0.07 |
|
Chromium (Cr) |
0.30 |
0.35 |
|
Nickel (Ni) |
0.80 |
0.85 |
|
Molybdenum (Mo) |
0.10 |
0.12 |
Mechanical Properties of S275N Steel Plate
|
Nominal Thickness (mm) |
Yield Strength ReH Min (MPa) |
Tensile Strength Rm (MPa) |
Elongation A Min (%) |
Charpy KV Longitudinal Min (J) at -20°C |
Charpy KV Transverse Min (J) at -20°C |
|---|---|---|---|---|---|
|
≤ 16 |
275 |
370–530 |
23 |
47 |
31 |
|
16 < t ≤ 40 |
265 |
370–530 |
23 |
47 |
31 |
|
40 < t ≤ 63 |
255 |
370–530 |
23 |
47 |
31 |
|
63 < t ≤ 80 |
245 |
370–530 |
22 |
47 |
31 |
|
80 < t ≤ 100 |
235 |
370–530 |
22 |
47 |
31 |
|
100 < t ≤ 150 |
225 |
350–510 |
22 |
47 |
31 |
|
150 < t ≤ 200 |
215 |
350–510 |
22 |
47 |
31 |
|
200 < t ≤ 250 |
195 |
350–510 |
22 |
47 |
31 |
Mechanical Properties of S420N Steel Plate
|
Thickness (mm) |
Yield Strength (min, MPa) |
Tensile Strength (MPa) |
Elongation (min, %) |
Impact Energy (min, J @ -20°C) |
|---|---|---|---|---|
|
≤16 |
420 |
520-680 |
19 |
27 |
|
16<t≤40 |
400 |
520-680 |
19 |
27 |
|
40<t≤63 |
390 |
520-680 |
19 |
27 |
|
63<t≤80 |
340 |
520-680 |
19 |
27 |
|
80<t≤100 |
290 |
520-680 |
19 |
27 |
|
100<t≤150 |
260 |
520-680 |
20 |
27 |
|
150<t≤200 |
220 |
500-650 |
20 |
27 |
Key Differences
Yield Strength: S420N (420 MPa) is significantly stronger than S275N (275 MPa).
Application: S275N for general use; S420N for high-strength, heavy-duty, or cold-weather uses.
Cost & Availability: S275N is often more common and economical, while S420N is a premium, higher-strength option.
