P540 Nonmagnetic Steel
P540 Nonmagnetic Steel
1. CHEMICAL COMPOSITION
P540 is a special nonmagnetic, austenitic Mn-Cr-N-steel with a nitrogen content of ≤ 2%.
| C | Mn | Cr | Mo | N | Ni |
| max. 0,05 | 19,00 – 21,00 | 17,00 – 19,50 | 0,30 – 0,80 | min. 0,50 | 0,80 – 2,00 |
2. MECHANICAL PROPERTIES
Following mechanical properties (tested at room temperature) are achieved by a special cold-working process over the full length of the collar:
| TEXT | OD | KSI | N/MM |
| Yield Strength (min.) 0,2%-offset method: | OD up to 9 1/4“ | 120 ksi | 830 N/mm² |
| OD 9 1/2“ and larger | 110 ksi | 760 N/mm² | |
| Tensile Strength (min.): | 130 ksi | 900 N/mm² | |
| Elongation (min.): | 0.2 | 0.2 | |
| Reduction of area (min.): | 0.5 | 0.5 | |
| Impact energy (min.): | 90 ft.lb | 122 J | |
| Endurance Strength / N=10⁵ (min.): | ± 65 ksi | ± 455 N/mm² | |
| Hardness Brinell: (min.): | 285-400 HB | 285-400 HB |
3. MAGNETIC PROPERTIES
Relative permeability: ≤ 1,005.
4. CORROSION RESISTANCE
- Transgranular SCC: Prevented by special surface treatments (Hammer peening, roller burnishing, shot peening).
- Intergranular SCC: The occurrence of material sensitization is prevented by quenching after warmforging. Each collar is tested according to ASTM A 262, Pract.A and E, last edition.
- Pitting Corrosion: Due to a high chromium- and nitrogen content a high resistance to pitting corrosion is given.
5. NON-DESTRUCTIVE TESTING
- Magnetic inspection: Drill collars are 100% tested by a proprietary probe-testing process using a Förster Magnetomat 1.782. (“Hot Spot“-test). Magnetic permeability of each collar is certified with the printout of probe-testing.
- Ultrasonic inspection: Each collar is ultrasonically inspected over 100% of the volume according to ASTM E 114, last edition as a minimum level.
