KS · KS D 4122
Unalloyed carbon steel used for forged pressure piping components (flanges, fittings, valve bodies) in ambient to moderately elevated temperature service. It's the most common item in industrial carbon-steel piping bills of materials, serving as the baseline reference before selecting an alloy steel for more severe service (high temperature, low temperature, corrosive media).
| Grade | Region | Standard | Re (MPa) | Rm (MPa) | Delta |
|---|---|---|---|---|---|
| SFVC2A | KR | KS D 4122 | 245 | 490–637 | reference |
| P245GH (1.0352) | EU | EN 10222-2 | 245 | 410–530 | 0% |
| SFVC2A | JP | JIS G3202 | 245 | 490–640 | 0% |
| A105 | US | ASTM A105/A105M (ASME SA-105) | 250 | ≥485 | +2% |
| Grade | C | Mn | Si | P | S |
|---|---|---|---|---|---|
| SFVC2A | ≤0.35 | 0.4–1.1 | ≤0.35 | ≤0.03 | ≤0.03 |
| P245GH (1.0352) | 0.08–0.2 | 0.5–1.3 | ≤0.4 | ≤0.025 | ≤0.015 |
| SFVC2A | ≤0.35 | 0.4–1.1 | ≤0.35 | ≤0.03 | ≤0.03 |
| A105 | ≤0.35 | 0.6–1.05 | 0.1–0.35 | ≤0.035 | ≤0.04 |
Note: Correction to the original brief: KS D 4122 ("Carbon steel forgings for pressure vessels") is the relevant Korean standard, modeled on JIS G3202 with the same grade designations (SFVC1, SFVC2A, SFVC2B) — not KS D 3752, which actually covers carbon steel for mechanical use (equivalent to JIS G4051/SM45C), unrelated to pressure flanges. The SFVC2A designation under KS D 4122 is corroborated by an independent Korean source (Rm ≈ 490-637 MPa), consistent with the JIS values.
Values compiled from public sources for guidance only — always verify against the official standard before use in design or fabrication.