SA387 Grade 12 Class 2
1Cr-0.5Mo pressure vessel plate. The economical Cr-Mo grade for moderate temperature pressure parts, widely used for separator and drum shells where creep and hydrogen resistance are needed but the duty is below the 2.25Cr range.
- Chromium-molybdenum creep strength at elevated temperature
- Resistance to hydrogen attack (Nelson curve service)
- Supplied normalised and tempered with simulated PWHT on request
- Ultrasonic testing to SA578 and through-thickness Z grades available
Available forms & sizes
| Form | Size range |
|---|---|
| Plates | 6 - 150 mm thk, up to 3000 mm wide, N or Q+T |
| Flanges | 1/2" - 24", 150# - 2500#, F11 / F12 / F22 / F5 / F9 / F91 |
| Fittings | 1/2" - 24" butt weld fittings, WP11 / WP22 / WP91 |
Chemical composition (%)
| Element | Min | Max |
|---|---|---|
| C | 0.05 | 0.17 |
| Cr | 0.80 | 1.15 |
| Mo | 0.45 | 0.60 |
| Si | 0.15 | 0.40 |
| Mn | 0.40 | 0.65 |
Mechanical properties
| Property | Value | Unit |
|---|---|---|
| Yield Strength (0.2%) | 275 min | MPa |
| Tensile Strength | 450 - 585 | MPa |
| Elongation | 18 min | % |
| Condition | Normalised and tempered | - |
Physical properties
| Property | Value | Unit |
|---|---|---|
| Density | 7.85 | g/cm3 |
| Max Service Temperature | 550 - 650 depending on grade | C |
Typical applications
Frequently asked
[ 02 ] Other grades in Alloy Steel
AISI 4140 / 42CrMo4
Ex-stock DubaiThe benchmark chromium-molybdenum through-hardening engineering steel. Excellent combination of strength, toughness and machinability in the quenched and tempered condition.
AISI 4340 / 34CrNiMo6
Mill indentNickel-chromium-molybdenum steel with very high hardenability and toughness in heavy sections, chosen for the most highly stressed machined components.
SA387 Grade 11 Class 2
Mill indent1.25Cr-0.5Mo-Si pressure vessel plate. The silicon addition improves oxidation resistance, making Grade 11 the common choice for hot wall vessels and hydrogen service up to around 550 C where full 2.25Cr strength is not required.
SA387 Grade 22 Class 2
Mill indent2.25Cr-1Mo pressure vessel plate — the refinery standard for hydroprocessing. The higher chromium and molybdenum push the Nelson curve limit well above Grade 11, which is why reactors, separators and hot wall equipment in hydrogen service specify it.
SA387 Grade 5 Class 2
Mill indent5Cr-0.5Mo plate. The chromium level lifts resistance to sulphidic corrosion and high temperature oxidation, so Grade 5 is specified for crude and vacuum unit hot sections where naphthenic and sulphur attack dominate.
SA387 Grade 9 Class 2
Mill indent9Cr-1Mo plate for high temperature service. Used where sulphidic corrosion resistance and creep strength have to be carried above the 5Cr range, typically in refinery heaters and transfer line equipment.