A martensitic steel containing 9% chromium and 1% molybdenum is most commonly used in the hardened and tempered condition.
Though often referred to as a stainless steel the grade does not meet the accepted criteria to be considered a stainless steel.
Used extensively as tubulars, structural and pressure containing members.
This alloy may be subject to accelerated local corrosion in environments containing free oxygen.
| C | Si | Mn | P | S | Cr | Mo | Fe | |
|---|---|---|---|---|---|---|---|---|
| Min | 0.05 | 0.30 | 0.25 | - | - | 8.00 | 0.90 | 0.00 |
| Max | 0.15 | 0.50 | 0.60 | 0.025 | 0.025 | 10.00 | 1.10 | - |