API 2W — Tempered high-strength steel plates for offshore platforms
Grades
Gr.50, Gr.60
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| Gr.50 | C≤0.23, Mn≤1.35, P≤0.040, S≤0.050, Nb+V 0.01-0.15 | Rm ≥450 MPa, Rp0.2 ≥345 MPa, A≥21% |
| Gr.60 | C≤0.26, Mn≤1.35, P≤0.040, S≤0.050, Nb+V 0.01-0.15 | Rm ≥520 MPa, Rp0.2 ≥415 MPa, A≥18% |
Application scope
API 2W specifies high-strength steel plates for offshore platform structures, including grades Gr.50 and Gr.60, delivered in TMCP or quenched and tempered condition. The standard provides high strength and excellent low-temperature impact toughness, specifies composition and mechanical requirements, emphasizes good weldability, and is approved by the relevant system. It is suitable for welded structures in thick-walled and heavily loaded areas of offshore platforms.
Typical applications
Primarily used in critical structures, node pipes, thick-walled components, and heavy-load areas of offshore platforms, suitable for areas with stress concentration and high strength requirements. Grades are classified by strength, allowing selection based on load and plate thickness. Leveraging the high strength, low-temperature toughness, and good weldability provided by TMCP or quenching and tempering, it is suitable for heavy marine engineering structures subjected to long-term cyclic loading and low-temperature marine environments.
