Datalloy 2 Cr-Mn-N Steel Round Bar

Product Description

Datalloy 2® (often processed as Datalloy 2 ESR) is a proprietary, ultra-clean, non-magnetic austenitic stainless steel manufactured by ATI (Allegheny Technologies Inc.). Utilizing Electro Slag Remelting (ESR), this Chromium-Manganese-Nitrogen ($\text{Cr-Mn-N}$) alloy is specifically engineered to replace standard $\text{Cr-Mn}$ steels in demanding, highly corrosive oilfield environments.

Its hallmark traits are a virtually transparent magnetic footprint, exceptionally high yield strength derived from cold working, and engineered resistance to galvanic and pitting corrosion.

Chemical Composition (Nominal Analysis %)

Unlike baseline amagnetic manganese steels, Datalloy 2 incorporates balanced additions of Nickel ($\text{Ni}$) and Molybdenum ($\text{Mo}$) alongside a low carbon profile to enhance localized corrosion resistance without destabilizing its non-magnetic matrix.

• Carbon (C): 0.03% (Low carbon limits carbide precipitation at grain boundaries)

• Manganese (Mn): 15.1% (Primary austenite stabilizer)

• Chromium (Cr): 15.3% (Provides pitting and general corrosion resistance)

• Nickel (Ni): 2.3% (Boosts resistance to galvanic attack and assists matrix stability)

• Molybdenum (Mo): 2.1% (Significantly increases resistance to chloride pitting)

• Nitrogen (N): 0.40% (Interstitial strengthener and austenite stabilizer)

• Silicon (Si): 0.30%

Key Technical & Magnetic Properties

• Maximum Magnetic Permeability ($\mu$): $\le 1.005$. It remains highly stable and amagnetic even after severe downhole mechanical stress or cold surface working.

• Galvanic Corrosion Resistance: Specially balanced to resist localized galvanic acceleration when directly coupled to dissimilar metals (such as pure copper or carbon steel components).

• Pitting & Stress Corrosion Cracking (SCC): The combination of $\text{Mo} + \text{Cr}$ gives it a high Pitting Resistance Equivalent Number (PREN) compared to standard $\text{Cr-Mn}$ oilfield alloys. It shows excellent resistance to transgranular SCC in warm chloride mud conditions.

Mechanical Properties (At Room Temperature)

Datalloy 2 cannot be hardened by traditional heat treatment. Instead, its high mechanical strength is achieved via tightly controlled hot forging combined with cold working (work-hardening). It is commonly specified to meet or exceed API 7-1 requirements and is supplied in two distinct structural conditions:

1. Standard Strength Condition

2. High Strength Condition

Physical Properties

• Density: $7.65 \text{ g/cm}^3$

• Modulus of Elasticity: $200 \text{ GPa}$

• Electrical Resistivity: $680 \mu\Omega\cdot\text{mm}$

• Coefficient of Thermal Expansion: $16 \times 10^{-6}\text{ / K}$

Machinability & Fabrication

Because Datalloy 2 is highly ductile and work-hardens rapidly during machining, tool dwell must be strictly avoided. Cutting feeds must be positive and continuous. It demonstrates similar machinability profiles to alternative downhole alloys like Staballoy AG17â„¢. To further enhance fatigue limits and surface protection in drill string setups, cold surface treatments like hammer or shot peening are frequently performed to embed deep compressive stresses.

Primary Applications

Datalloy 2 round bars are heavily utilized within directional drilling, oil & gas exploration, and specialized marine sectors for:

• MWD & LWD Tools: Measurement-While-Drilling and Logging-While-Drilling housings where sensitive magnetometers require a completely amagnetic enclosure.

• Non-Magnetic Drill Collars & Stabilizers

• Compressive Service Drill Pipes

• Heavy-Duty Amagnetic Fasteners & Downhole Shafting