ASTM A335 P11 seamless pipe is a typical chromium-molybdenum alloy steel pipe for high temperature use. Also known as 1.25Cr-0.5Mo, ASTM A335 P11 has the UNS number K11597. Its ASTM equivalent standards include ASTM A369 FP11 and ASTM A213 T11.
1. Chemical Composition Requirements
| ASTM A335 P11 Chemical Composition % | ||||||
|---|---|---|---|---|---|---|
| C | Mn | P | S | Si | Cr | Mo |
| 0.05-0.15 | 0.30-0.60 | ≤0.025 | ≤0.025 | 0.50-1.00 | 1.00-1.50 | 0.44-0.65 |
*C – Carbon, Mn – Manganese, P – Phosphorous, S – Sulfur, Si – Silicon, Cr-Chromium, Mo – Molybdenum.
2. Mechanical Properties Of ASTM A335 P11
The tensile strength shall be no less than 60 ksi (415MPa) while its yield strength shall be no less than 30 ksi (205MPa). The longitudinal and transverse elongation values measured in 2 inch or 50 mm (or 4D) shall be no less than 30% and 20% respectively.
3. Heat Treatment, Inspection & Test
Pipes of ASTM A335 P11 may be either cold drawn or hot rolled. Each pipe shall be reheated for heat treatment – full or isothermal annealing, normalizing and tempering at a temperature no less than 1200°F(650°C).
Hydrostatic test shall be performed on each pipe length of ASTM A335 P11 along with dimensional inspection and visual examination. Longitudinal or transverse tension test, flattening test, or bend test shall be performed for each heat number of furnace. When specified by the purchaser, one of the alternative nondestructive tests can be performed: ultrasonic test, eddy current test, or flux leakage examination. Hardness test is not necessary.
