Stainless Alloy Steel C50TF84 (GE) Bars, C50TF84 (GE) Rods / C50TF84 (GE) Rings

Product Description

C50TF84 Stainless Alloy Steel (GE Aviation)

C50TF84 is a proprietary, high-performance stainless steel specification developed by GE Aviation for use in aircraft engine components. It belongs to the family of precipitation-hardening (PH) martensitic stainless steels, very similar in chemistry and performance to the industry-standard 17-4 PH (AISI 630), but governed by GE's stringent quality, melting, and testing requirements.

Material certified to C50TF84 is designed to operate in high-stress environments where a combination of moderate corrosion resistance and high mechanical strength is required at temperatures up to approximately 315°C (600°F).

Technical Specifications & Control

Because C50TF84 is a GE-specific "TF" (Technical Form) specification, it often mandates tighter controls on trace elements and processing than standard commercial grades.

Material Conditions

Similar to the British "S" series, GE's C50TF84 specification defines different classes based on the heat treatment (aging) applied to the bar or ring:

• Class A (Solution Treated): The material is in its softest state, suitable for severe machining or forming.

• Class B/C/D (Hardened): The material has been aged at specific temperatures (e.g., 900°F, 1025°F, or 1150°F) to achieve a precise balance of tensile strength and fracture toughness.

Typical Mechanical Properties

When supplied in a hardened condition (e.g., equivalent to H1025), the material typically exhibits the following:

• Tensile Strength ($R_m$):$\ge$ 1070 MPa (155 ksi)

• 0.2% Yield Strength ($R_{p0.2}$):$\ge$ 1000 MPa (145 ksi)

• Elongation:$\ge$ 12%

• Hardness: 35–42 HRC (depending on the specific aging class)

Product Forms & GE Applications

1. Round Bars & Rods

C50TF84 bars are typically produced via Vacuum Induction Melting (VIM) followed by Vacuum Arc Remelting (VAR) to ensure extreme cleanliness.

• Use Cases: Compressor Vanes, structural bolts, and engine mount components.

2. Rings & Forgings

Rings are usually supplied as seamless rolled rings or forged blanks. The GE specification often requires ultrasonic testing and grain size control to ensure the integrity of the rotating or pressure-containing part.

• Use Cases: Actuator rings, seal carriers, and housing flanges in GE jet engines (such as the CF6, CFM56, and GE90 series).

Key Performance Benefits

• Corrosion Resistance: Superior to standard 400-series martensitic steels; it resists the "pitting" often caused by moisture and salt in coastal airfields.

• Stability: Maintains high fatigue strength and dimensional stability under the thermal cycling common in turbine environments.

• Fabrication: While high-strength, it is more weldable than most martensitic stainless steels because it does not require the extensive pre-heating typically associated with high-carbon grades.

Procurement Note

When sourcing C50TF84, it is critical to confirm the Revision Level of the GE specification and the required Class (Heat Treat condition), as these dictate the final mechanical testing parameters required for GE-certified hardware.