Products Description
ASTM A335 / ASME SA335 Pipe named chrome moly pipe as they have a high level of Chromium and Molybdenum.
Chromium will increase oxidation resistance and provides high-temperature strength, along with the better tensile & yield strength and proper hardness at room temperature. When the chromium levels are above 12%, it can be classified as stainless steel.
Molybdenum increases the overall strength, resistance, elasticity, hardenability and overall quality, moly ensures that the material is more resistant to softening, restrains the growth of grains and lessens the chances of embrittlement.
It is the single additive that is responsible for the increase in high temperature resistance (to 540-750°C) and it also improves the corrosion resistance to steel.
P9 Pipe Specifications
Tensile strength, min, PSI, (MPa) – 60,000 (415)
Yield Strength, min, (MPa) – 30,000 (205)
Chemical Composition
| Element | Symbol | Content (%) | Notes / Function |
|---|---|---|---|
| Carbon | C | 0.08 – 0.12 | Controls hardness and strength |
| Silicon | Si | 0.17 – 0.37 | Enhances oxidation resistance |
| Manganese | Mn | 0.30 – 0.60 | Improves tensile strength |
| Phosphorus | P | ≤0.025 | Low P improves toughness |
| Sulfur | S | ≤0.015 | Low S avoids brittleness |
| Chromium | Cr | 0.85 – 1.05 | Provides high-temperature corrosion resistance |
| Molybdenum | Mo | 0.44 – 0.65 | Strengthens at high temperature, prevents creep |
| Nickel | Ni | ≤0.40 | Optional, improves toughness |
| Vanadium | V | ≤0.12 | Grain refinement, increases strength |
Physical & Mechanical Properties
| Property | Symbol / Unit | Typical Value | Notes |
|---|---|---|---|
| Yield Strength | σy (MPa) | ≥205 | At room temperature |
| Tensile Strength | σb (MPa) | 415 – 550 | Typical for seamless pipes |
| Elongation | δ (%) | ≥20 | Ensures ductility |
| Hardness | HB | 160 – 200 | Brinell hardness |
| Impact Energy | KV (J) | ≥27 at -29°C | Charpy V-notch test |
| Density | ρ (g/cm³) | 7.85 | Standard for ferritic steel |
| Thermal Conductivity | λ (W/m·K) | 40 – 45 | At 100°C |
| Modulus of Elasticity | E (GPa) | 205 | Linear elastic range |
| Operating Temperature | °C | Up to 540 | Suitable for high-temperature steam pipelines |
| Corrosion Resistance | – | Moderate | Best for high-temperature oxidation environment |
| Standard | – | ASTM A335 P9 / EN 10216-2 P9 | Seamless ferritic alloy pipe standard |
