DB120 non-magnetic material

DB120 is a non-magnetic Mn-Cr material which due to the chemical composition and the special cold-working process is less susceptible to galling than Cr-Ni steels.

Mechanical Properties:

The following properties are achieved by a special cold-working process over the full length of the bar:

Yield strength (0.2 % offset, min.)

• 120 ksi (up to 7¡± diameter)
• 110 ksi (7¡± diameter and larger)

Tensile strength (min.): 130 ksi

Elongation (min.): 25 %

Reduction of area (min.): 50 %

Impact energy (min.): 100 ft.lb.

Hardness Brinell: 285 ¨C 350 BHN 2.

Magnetic Properties: Relative permeability: ¡Ü 1,001 3.

Chemical Composition:

DB 120 is a special Mn-Cr austenitic steel with a Nickel content of ¡Ü 2 %.

Corrosion Resistance:

Transgranular SCC: Prevented when compressive surface treatment is applied (ID Plus, Roller-burnishing or shotpeening).

Intergranular SCC: The occurrence of sensitization is prevented by quenching after forging and subsequent coldworking. Each collar is checked according to ASTM 262, Practice A and E, latest edition.

Non-destructive Testing: ¡¤

Magnetic: Drill collars are 100 % tested by a proprietary probe-testing process. Magnetic permeability of each collar is certified with the printout of probe-testing equipment.

Ultrasonic: Each collar is ultrasonically inspected according to ASTM E114 & A745, latest edition.

Galling Resistance:

DB120 is a non-magnetic Mn-Cr material which due to the chemical composition and the special coldworking process is less susceptible to galling than Cr-Ni steels.