ASTM A387/A387M — Chromium-molybdenum alloy steel plates for pressure vessels
Grades
Gr.2, Gr.12, Gr.11, Gr.22, Gr.5, Gr.9, Gr.91, Gr.21, Gr.22L, Gr.911
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| Gr.2 | C≤0.21, Mn 0.55-0.80, P≤0.025, S≤0.025, Si 0.15-0.40, Cr 0.50-0.80, Mo 0.45-0.60 | Rm 380-550 MPa, Rp0.2 ≥230 MPa, A≥18%, Normalizing + Tempering |
| Gr.12 | C≤0.17, Mn 0.40-0.65, P≤0.025, S≤0.025, Si 0.15-0.40, Cr 0.80-1.15, Mo 0.45-0.60 | Rm 415-585 MPa, Rp0.2 ≥275 MPa, A≥19%, Normalizing + Tempering |
| Gr.11 | C≤0.17, Mn 0.40-0.65, P≤0.025, S≤0.025, Si 0.50-0.80, Cr 1.00-1.50, Mo 0.45-0.65 | Rm 415-585 MPa, Rp0.2 ≥310 MPa, A≥19%, Normalizing + Tempering |
Application scope
ASTM A387/A387M specifies chromium-molybdenum alloy steel plates for high-temperature and high-pressure vessels, covering multiple grades such as Gr.11, Gr.12, Gr.22, and Gr.91. They are delivered in normalized and tempered condition. Chromium-molybdenum alloying imparts excellent resistance to high temperatures, hydrogen, and creep, making them suitable for high-temperature hydrogen-bearing pressure equipment and thick-walled vessels.
Typical applications
It is widely used in oil refining hydrogenation reactors, high-temperature heat exchangers and petrochemical high-temperature containers, as well as in power plant boiler drums, high-temperature headers and pipe fittings; it can serve stably for a long time in high temperature, high pressure and hydrogen-containing environments, and has good creep resistance and hydrogen corrosion resistance. It is suitable for thick-walled pressure-bearing components with high requirements and long-term high temperature operation in the petrochemical and power industries.
