Q345R vs P355GH
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
Q345R
Structural & HSLA Steel
Q345R is China’s standard pressure-vessel plate to GB/T 713 — the R (容， vessel) variant of the Q345 family with tighter sulfur, phosphorus and inspection requirements. It is the default domestic grade for GB 150 coded vessels and the usual Chinese offer against A516 Gr.70.
Standards: DIN P355GH (near) · AISI A516 Gr.70 (near) · GB Q345R (GB/T 713)
P355GH
Structural & HSLA Steel
P355GH is the EN 10028-2 carbon steel for pressure purposes at elevated temperature — the European counterpart of A516 Gr.70 for boilers and PED vessels. The GH suffix denotes guaranteed high-temperature proof strength.
Standards: DIN 1.0473 (P355GH) · AISI A516 Gr.70 (near) · JIS SGV480 (near) · GB Q345R (near)
Chemical composition compared (%)
| Element | Q345R | P355GH |
|---|---|---|
| C | ≤0.20 | 0.10–0.22 |
| Si | 0.15–0.40 | ≤0.60 |
| Mn | 1.20–1.60 | 1.10–1.70 |
| P | ≤0.025 | ≤0.025 |
| S | ≤0.015 | ≤0.015 |
| Al | ≥0.020 | — |
| Cr | — | ≤0.30 |
| Ni | — | ≤0.30 |
Properties compared
| Property | Q345R | P355GH |
|---|---|---|
| Yield strength | ≥345 MPa (≤16 mm) | ≥355 MPa (≤16 mm) |
| Tensile strength | 510–640 MPa | 510–650 MPa |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
| Impact | — | Tested at 20 °C per EN 10028-2 |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: Q345R · P355GH. Substitution decisions for certified parts stay with the design authority.