P670

1. CHEMICAL COMPOSITION

„P670“ is a special nonmagnetic, austenitic Cr-Ni-Mn -steel with a high nitrogen content.

C Mn Cr Mo N Ni
max. 0,06 19,50 - 22,00 19,50 - 22,00 min. 2,20 min. 0,60 8,50 - 10,00

 

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“ 160 ksi 1103 N/mm²
  OD 9 1/2“ and larger 150 ksi 1034 N/mm²
Tensile Strength (min.):   170 ksi 1172 N/mm²
Elongation (min.):   20% 20%
Reduction of area (min.):   50% 50%
Impact energy (min.):   80 ft.lb 108 J
Endurance Strength / N=10⁵ (min.):   ± 80 ksi ± 550 N/mm²
Hardness Brinell: (min.):   350-450 HB 350-450 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, Pract.A and E, last edition.

• Pitting Corrosion: Due to a high chromium- and nitrogen content a 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.