Precision Manufacturing of Nickel Alloy 716 Round Bars by SASAALLOY

In the world of advanced engineering materials, Nickel Alloy 716 Round Bar has become a cornerstone for high-performance applications that demand superior strength, corrosion resistance, and high-temperature stability. Used across industries such as aerospace, energy, chemical processing, oil and gas, and marine engineering, this alloy is renowned for its ability to perform under extreme conditions where standard materials fail.

Behind the reliability of this alloy lies a meticulous manufacturing process. Every step — from raw material selection to final inspection — must be executed with precision to meet international standards.

This article explores how SASAALLOY, a global leader in high-performance materials, ensures the precision manufacturing of Nickel Alloy 716 Round Bars, delivering consistent quality, mechanical strength, and dimensional accuracy for critical applications worldwide.

Understanding Nickel Alloy 716

Nickel Alloy 716, derived from the Inconel 718 family, is a precipitation-hardened nickel-chromium-iron alloy strengthened primarily by niobium, molybdenum, titanium, and aluminum. It exhibits excellent mechanical strength and outstanding corrosion and oxidation resistance, even at temperatures reaching 700°C (1300°F).

Key Properties:

• Exceptional tensile and yield strength

• Superior resistance to stress corrosion cracking and oxidation

• Stable microstructure under high thermal stress

• Excellent weldability and machinability compared to other nickel-based alloys

• Long-term performance in both high and low temperature environments

At SASAALLOY, these properties are enhanced through controlled melting, forging, heat treatment, and precision machining, ensuring the final round bars meet the most demanding industrial specifications.

Step 1: Raw Material Selection and Melting

The precision manufacturing process begins with strict raw material selection. Only certified high-purity nickel, chromium, iron, and alloying elements are used, ensuring chemical consistency and traceability.

1. Vacuum Induction Melting (VIM)

The raw materials are melted in a vacuum induction furnace to eliminate impurities such as oxygen, nitrogen, and sulfur. This ensures a clean melt with excellent chemical homogeneity.

2. Vacuum Arc Remelting (VAR)

After the initial melting, the alloy undergoes a secondary remelting process to further refine the structure. VAR enhances cleanliness, reduces segregation, and ensures uniform distribution of alloying elements.

This double-melting method provides superior metallurgical integrity, a hallmark of all SASAALLOY Nickel Alloy 716 Round Bars.

Step 2: Forging and Hot Working

Once the ingot is melted and solidified, it undergoes forging and hot working to convert it into a bar shape with refined grain structure and enhanced mechanical properties.

Forging Process:

• Temperature Range: 980°C to 1150°C (1800°F–2100°F)

• Forging Equipment: Hydraulic presses and automated forging hammers

• Deformation Control: Low strain rates and uniform reduction to avoid cracking

Forging breaks down the ingot structure, refines grains, and improves isotropy. The process ensures that the mechanical properties are consistent across all directions of the bar — a crucial requirement for aerospace and energy applications.

Cooling and Straightening:

The forged bars are cooled under controlled conditions to avoid residual stresses and distortion. After cooling, precision straightening ensures perfect alignment and dimensional accuracy.

Step 3: Precision Heat Treatment

Heat treatment is the most critical stage in developing the strength and stability of Nickel Alloy 716. It involves carefully controlled heating and cooling cycles designed to achieve the desired microstructure.

1. Solution Annealing

• Temperature: 950°C–980°C

• Purpose: Dissolves segregated phases, homogenizes structure, and restores ductility.

• Cooling: Rapid air or water quenching to retain alloying elements in solid solution.

2. Aging (Precipitation Hardening)

• Temperature: Two-step aging at 720°C and 620°C.

• Purpose: Precipitates fine γ′ (Ni₃(Al,Ti)) and γ″ (Ni₃Nb) phases, dramatically increasing strength.

This carefully timed process transforms the alloy into its final hardened state while maintaining ductility and corrosion resistance.

At SASAALLOY, all heat treatments are performed in computer-controlled furnaces with temperature accuracy within ±2°C, ensuring consistent metallurgical results across every batch.

Step 4: Precision Machining

Machining Nickel Alloy 716 requires expertise and specialized equipment due to its work-hardening nature and high strength. SASAALLOY uses advanced CNC machining centers to achieve tight dimensional tolerances and smooth surface finishes.

Machining Techniques:

• Cutting Tools: High-speed carbide or ceramic inserts with optimized geometry.

• Coolant Systems: High-pressure emulsion cooling to minimize tool wear and maintain precision.

• Feed Rates and Speeds: Controlled to balance productivity with surface quality.

Precision machining ensures perfect roundness, uniform diameter, and straightness — essential for components used in high-stress environments.

Step 5: Surface Finishing and Inspection

After machining, surface finishing operations such as polishing, turning, and grinding are carried out to achieve the desired smoothness and tolerance.

• Finish Options: Bright turned, polished, or ground finish.

• Dimensional Tolerance: As tight as ±0.05 mm depending on customer requirements.

• Surface Roughness (Ra): Typically ≤ 0.8 μm.

Once finished, every Nickel Alloy 716 Round Bar undergoes comprehensive inspection to ensure flawless quality.

Step 6: Testing and Quality Control

SASAALLOY maintains a strict multi-stage quality control system that ensures every bar meets international standards such as ASTM B637, AMS 5662/5663, and EN 10204 3.1/3.2.

Mechanical Testing:

• Tensile Test (ASTM E8): Measures yield and ultimate strength.

• Hardness Test (ASTM E18): Confirms proper aging and precipitation hardening.

• Impact Test (ASTM E23): Ensures toughness at different temperatures.

• Creep and Fatigue Tests: Assess long-term durability under load and temperature.

Non-Destructive Testing (NDT):

• Ultrasonic Testing (ASTM A388): Detects internal defects.

• Eddy Current Testing (ASTM E309): Checks surface discontinuities.

• Radiographic Examination: For detecting inclusions and structural uniformity.

Chemical and Microstructural Analysis:

• Spectrographic Testing: Confirms chemical composition.

• Metallography (ASTM E112): Evaluates grain size and precipitate distribution.

These quality measures guarantee that SASAALLOY Nickel Alloy 716 Round Bars deliver reliable performance in the most challenging environments.

Step 7: Packaging and Logistics

Each finished bar is carefully cleaned, marked, and packaged to ensure safe global shipment.

Standard Packaging Includes:

• PVC coating or anti-rust oiling for corrosion protection

• End caps for thread and edge safety

• Wooden cases or steel crates for sea freight

• Custom labeling with heat number, grade, and specifications

This attention to detail ensures that customers receive products in perfect condition, ready for immediate use or further fabrication.

Applications of SASAALLOY Nickel Alloy 716 Round Bars

Thanks to its combination of strength, ductility, and corrosion resistance, Nickel Alloy 716 is indispensable in numerous critical industries:

1. Aerospace Industry:

   • Turbine shafts, bolts, and compressor parts requiring high fatigue resistance.

2. Oil & Gas Exploration:

   • Downhole tools, wellhead components, and valves exposed to sour gas and extreme pressures.

3. Power Generation:

   • Steam turbines, nuclear reactor cores, and heat exchangers.

4. Chemical Processing:

   • Reactor vessels, pumps, and acid-resistant piping systems.

5. Marine and Defense Applications:

   • High-strength fasteners, propeller shafts, and marine hardware exposed to saltwater.

In all these applications, SASAALLOY’s precision-manufactured Nickel Alloy 716 Round Bars ensure consistent mechanical reliability and corrosion resistance.

Advantages of SASAALLOY Manufacturing

SASAALLOY differentiates itself in the global market through innovation, precision, and quality.

Key Advantages:

• Advanced Production Facilities: Integrated melting, forging, heat treatment, and CNC machining.

• Strict Quality Control: In-house testing labs and certification per ASTM, AMS, and NACE standards.

• Customized Solutions: Tailor-made sizes, tolerances, and mechanical properties for client-specific needs.

• Global Reach: Reliable supply chain and on-time delivery to over 50 countries.

• Technical Expertise: Decades of metallurgical experience in high-performance alloys.

These capabilities make SASAALLOY a preferred partner for companies seeking consistent quality and reliability in nickel alloy materials.

Commitment to Excellence

From alloy development to final inspection, SASAALLOY maintains a philosophy of precision, consistency, and innovation. Each stage of production is executed with attention to detail, supported by skilled engineers and automated process control systems.

Our goal is to provide Nickel Alloy 716 Round Bars that not only meet specifications but exceed expectations in performance and durability — ensuring long-term customer satisfaction and operational safety.

Conclusion

The precision manufacturing of Nickel Alloy 716 Round Bars represents a perfect synergy of advanced metallurgy, high-end equipment, and technical expertise. Through controlled melting, forging, heat treatment, machining, and testing, SASAALLOY produces materials that stand up to the toughest industrial challenges.

Whether used in aerospace turbines, deep-sea drilling systems, or high-temperature reactors, SASAALLOY Nickel Alloy 716 Round Bars deliver unmatched strength, stability, and reliability.