P550 Nonmagnetic Steel
P550 Nonmagnetic Steel
We produce P550 non-mag material Steel Bars and Non Magnetic Hollow Bars.
1. CHEMICAL COMPOSITION
P550 is a special nonmagnetic, austenitic Mn-Cr-steel with a high nitrogen content.
| C | Mn | Cr | Mo | N | Ni |
| max. 0,06 | 20,50 – 21,60 | 18,30 – 20,00 | min. 0,50 | min. 0,60 | min. 1,40 |
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“ | 140 ksi | 965 N/mm² |
| OD 9 1/2“ and larger | 130 ksi | 900 N/mm² | |
| Tensile Strength (min.): | 150 ksi | 1035 N/mm² | |
| Elongation (min.): | 20% | 20% | |
| Reduction of area (min.): | 50% | 50% | |
| Impact energy (min.): | 60 ft.lb | 82 J | |
| Endurance Strength / N=10⁵ (min.): | ± 80 ksi | ± 550 N/mm² | |
| Hardness Brinell: (min.): | 335-450 HB | 335-450 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, Prat.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. 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.
