Superalloy Equiaxed Crystal Castings Heat Treatment Supplier

Core Heat Treatment Services for Equiaxed Superalloy Castings

Our heat treatment facility delivers precise thermal cycles and atmosphere control to enhance microstructural integrity and mechanical properties.

• Solution annealing at 1120–1180°C to dissolve segregated phases and homogenize grain structure

• Aging at 800–870°C to control gamma prime size, dispersion, and hardness

• Stress relief cycles for machined components to minimize distortion

• Vacuum or inert gas atmosphere to avoid oxidation and contamination

Each thermal profile is customized by alloy, geometry, and downstream machining or coating processes.

Typical Alloys Treated in Equiaxed Crystal Form

These alloys respond well to heat treatment and are designed for oxidation, fatigue, and creep resistance.

Case Study: Aging and Stress Relief of Inconel 738 NGV Segments

Project Background

A gas turbine customer supplied Inconel 738 cast NGV segments requiring solution heat treatment, aging, and final stress relief. The goal was to stabilize grain boundaries and optimize gamma prime distribution. The process cycle included solution annealing at 1160°C, aging at 845°C for 16 hours, and vacuum furnace cooling.

Treated Components and Industries

Each component is verified through hardness testing, grain size analysis, and X-ray examination.

Key Heat Treatment Challenges for Equiaxed Superalloys

1. Phase segregation at interdendritic regions without proper homogenization

2. Carbide agglomeration if overheating exceeds 1200°C during solution treatment

3. Thermal distortion in large vanes and thin-walled features

4. Grain growth suppression required during prolonged high-temperature holding

5. Precipitate size control critical for creep resistance and fatigue performance

Thermal Processing Solutions

• Ramp-controlled furnaces accurate to ±2°C across the charge zone

• Vacuum or argon chamber treatment to eliminate oxidation and contamination

• HIP integration prior to heat treatment for porosity removal

• Multi-zone gas flow mapping for uniform thermal exposure

• Controlled aging at 845°C ±5°C to achieve 350–400 HV hardness in Inconel 738

Results and Quality Validation

Processing Execution

Parts were treated in multi-cycle programmable furnaces with atmosphere control. Core segments held dimensional tolerances within ±0.03 mm after aging and machining.

Metallographic Results

SEM confirmed uniform gamma prime distribution. Grain size across equiaxed blades met ASTM 6–7. No oxide penetration or carbide coalescence detected.

Final Inspection

CMM confirmed profile stability. X-ray and SEM validated metallurgical integrity. Final hardness matched design criteria (370–390 HV).

FAQs

1. What is the optimal aging cycle for Inconel 738 equiaxed castings?

2. Can you heat treat Rene 77 nozzles without causing dimensional warping?

3. What atmosphere is used during high-temp solution treatment?

4. How is grain growth controlled in large turbine vane castings?

5. Do you offer integrated HIP and heat treatment for equiaxed turbine components?