P265GH and P355GH are European standard (EN 10028-2) carbon-manganese steels for welded pressure vessels and boilers, differing mainly in strength: P355GH offers higher minimum yield strength (355 MPa) than P265GH (265 MPa) at thinner gauges, making it stronger for demanding high-temperature/pressure applications, while both provide good weldability and toughness for industries like petrochemical, oil & gas, and power generation.
Mechnical property
| Thickness(mm) | Yield strength (≥Mpa) | Tensile strength (Mpa) | Elongation in ≥,% |
| T≤16 | 265 | 410-530 | 22 |
| 16<T≤40 | 255 | ||
| 40<T≤60 | 245 | ||
| 60<T≤100 | 215 | ||
| 100<T≤150 | 200 | 400-530 | |
| 150<T | 185 | 390-530 |
|
Grade |
|
P355GH Mechanical Property |
|||||
|
Thickness |
Yield |
Tensilmie |
Elongation |
Impact Energy(KV J) min |
|||
|
P355GH |
mm |
Min Mpa |
Mpa |
Min % |
-20° |
0° |
+20° |
|
≤ 16 |
355 |
510-650 |
20 |
27 |
34 |
40 |
|
|
16> to ≤40 |
345 |
510-650 |
20 |
27 |
34 |
40 |
|
|
40> to ≤60 |
335 |
510-650 |
20 |
27 |
34 |
40 |
|
|
60> to ≤100 |
315 |
490-630 |
20 |
27 |
34 |
40 |
|
|
100> to ≤150 |
295 |
480-630 |
20 |
27 |
34 |
40 |
|
|
150> to ≤250 |
280 |
470-630 |
20 |
27 |
34 |
40 |
|
Chemical composition
| Main chemical elements composition of P265GH boiler plate | |||||||
| C | Si | Mn | P | S | Al (total) | N | Cr |
| 0.20 | 0.40 | 0.80-1.40 | 0.025 | 0.015 | ≥0.020 | 0.012 | 0.30 |
| Cu | Mo | Nb | Ni | Ti | V | Cr+Cu+Mo+Ni | |
| 0.30 | 0.08 | 0.020 | 0.30 | 0.03 | 0.02 | 0.70 | |
|
Main chemical elements composition of P355GH |
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|
Grade |
The Element Max (%) |
||||||
|
C |
Si |
Mn |
P |
S |
Al(min) |
N |
|
|
P355GH |
0.10-0.22 |
0.60 |
1.10-1.70 |
0.025 |
0.015 |
0.020 |
0.012 |
|
Cr |
Cu |
Mo |
Nb |
Ni |
Ti |
V |
|
|
0.30 |
0.30 |
0.08 |
0.040 |
0.30 |
0.03 |
0.02 |
|
Key Differences & Similarities
Standard: Both fall under EN 10028-2 for steels for pressure purposes, indicating suitability for high-temperature service.
Strength: P355GH has a significantly higher guaranteed minimum yield strength (355 MPa) compared to P265GH (265 MPa), making it a stronger material.
Application: Both are used for boilers, pressure vessels, and other high-pressure equipment in demanding environments.
Weldability: Both grades offer excellent weldability, crucial for fabrication.
Material Type: They are non-alloy, fine-grained structural steels designed for excellent toughness and heat resistance.
P265GH (Yield Strength ~265 MPa)
Designation: 'P' for Pressure, '265' for minimum yield strength, 'GH' for high temperature.
Applications: General purpose pressure vessels, boilers, piping.
Equivalents: ASTM A516 Gr. 60 or A515, Q245R.
P355GH (Yield Strength ~355 MPa)
Designation: 'P' for Pressure, '355' for minimum yield strength, 'GH' for high temperature.
Applications: More demanding pressure vessels, heavier duty applications requiring higher strength.
Equivalents: ASTM A52 CP, 19Mn 6.
