Mechanical Properties and Heat Treatment Guide for Nickel Alloy 716 Round Bar

Property	Typical Value
Tensile Strength	1250–1500 MPa
Yield Strength	900–1100 MPa
Elongation	12–20%
Reduction of Area	35–45%
Hardness	330–380 HB
Density	8.19 g/cm³
Operating Temperature Range	Up to 700°C (1290°F)

Key Mechanical Characteristics

1. High Tensile and Yield Strength
   The precipitation of γ′ (Ni₃(Al, Ti)) and γ″ (Ni₃Nb) phases strengthens the alloy matrix, giving it extremely high tensile and yield strength, even under sustained high temperatures.

2. Excellent Fatigue Resistance
   The refined grain structure achieved through forging and heat treatment enables Nickel Alloy 716 Round Bar to resist cyclic loading and fatigue cracking, ideal for rotating components like turbine blades and compressor shafts.

3. Superior Creep Resistance
   The alloy maintains dimensional stability under constant load and temperature, resisting time-dependent deformation (creep) during long-term exposure.

4. Outstanding Toughness and Ductility
   Unlike many high-strength alloys, Nickel Alloy 716 retains good ductility and impact toughness, minimizing the risk of brittle fracture during service or fabrication.

---

Heat Treatment Guide for Nickel Alloy 716 Round Bar

The heat treatment process is fundamental to developing the alloy’s full mechanical potential. Each step — from solution annealing to aging — plays a key role in optimizing strength, toughness, and corrosion resistance.

1. Solution Annealing

Purpose:
Dissolves carbides, segregated phases, and secondary precipitates to create a uniform solid solution, improving machinability and preparing the structure for aging.

Typical Parameters:

• Temperature: 980–1010°C (1800–1850°F)

• Holding Time: 1–2 hours (depending on diameter)

• Cooling: Rapid air or oil quenching to prevent reprecipitation

Effect:
This step produces a clean, homogeneous microstructure that ensures consistent response during subsequent hardening treatment.

---

2. Precipitation Hardening (Aging Treatment)

Purpose:
Promotes the controlled precipitation of gamma prime (γ′) and gamma double prime (γ″) phases, which significantly increase the alloy’s mechanical strength.

Typical Parameters:

• Temperature: 720–760°C (1325–1400°F)

• Duration: 8–10 hours

• Cooling: Air cooling

Effect:
During aging, finely dispersed Ni₃Nb (γ″) and Ni₃(Al, Ti) (γ′) precipitates form within the nickel matrix. These coherent precipitates hinder dislocation movement, dramatically improving yield strength, tensile strength, and fatigue life.

---

3. Stress Relief (Optional)

For components exposed to prolonged machining or welding, a stress-relief heat treatment at 870–900°C (1600–1650°F) may be performed before aging to minimize distortion and internal stress.

---

Microstructural Evolution During Heat Treatment

1. As-Forged Condition:
   The alloy consists of a fine-grained structure with minor segregation and internal stresses.

2. After Solution Annealing:
   A homogeneous gamma (γ) phase forms, ensuring chemical uniformity.

3. After Aging:
   The precipitation of γ′ and γ″ phases enhances the alloy’s hardness and stability. These phases remain stable up to 700°C, preventing softening and creep deformation.

The controlled combination of these microstructural transformations gives Nickel Alloy 716 Round Bar its hallmark properties — exceptional strength, toughness, and thermal endurance.

---

Influence of Heat Treatment on Mechanical Performance

As-Annealed Condition

• Tensile Strength: ~800 MPa

• Yield Strength: ~550 MPa

• Hardness: ~200 HB

• Excellent ductility, suitable for forming and machining

Aged Condition (Fully Hardened)

• Tensile Strength: 1250–1500 MPa

• Yield Strength: 900–1100 MPa

• Hardness: 330–380 HB

• High strength with balanced toughness and corrosion resistance

By adjusting aging time and temperature, engineers can fine-tune the balance between hardness, strength, and ductility to suit specific application requirements.

---

Machinability and Fabrication

Nickel Alloy 716 Round Bar offers good machinability and fabrication characteristics, especially after solution annealing. It can be forged, welded, and machined using conventional high-speed steel or carbide tools, provided cutting speeds are optimized to minimize work hardening.

• Welding: Suitable for gas-tungsten arc welding (GTAW) and gas-metal arc welding (GMAW).

• Forging Temperature: 980–1150°C (1800–2100°F).

• Post-Weld Heat Treatment: Recommended to restore corrosion and mechanical properties.

---

Applications of Nickel Alloy 716 Round Bar

Thanks to its superior mechanical and thermal properties, Nickel Alloy 716 Round Bar is widely used in industries that demand high strength, temperature stability, and corrosion resistance.

1. Aerospace Industry

• Jet engine components, turbine disks, and fasteners

• Afterburner parts and heat shields exposed to oxidation

• Compressor blades operating under cyclic thermal loading

2. Oil and Gas Industry

• Downhole tools, completion equipment, and valve components

• Subsea connectors and wellhead systems exposed to sour gas environments

• High-pressure tubing in offshore operations

3. Power Generation and Energy

• Steam and gas turbines, nuclear reactor parts, and heat exchangers

• Boiler tubes operating under high stress and temperature

4. Chemical and Petrochemical Plants

• Reactor vessels, acid processing equipment, and pressure fittings

• Heat exchanger tubing in corrosive and high-temperature environments

---

Advantages of Nickel Alloy 716 Round Bar

• Outstanding High-Temperature Strength – Retains mechanical integrity up to 700°C.

• Superior Corrosion Resistance – Resists oxidation, pitting, and crevice corrosion.

• Excellent Fatigue and Creep Resistance – Performs under cyclic and long-term stress.

• Good Machinability and Weldability – Allows precision fabrication.

• Stable Microstructure – Maintains strength and toughness after prolonged service.

• Long Service Life – Reduces maintenance costs and downtime.

---

Why Choose SASAALLOY for Nickel Alloy 716 Round Bar

At SASAALLOY, we specialize in the manufacturing, heat treatment, and supply of Nickel Alloy 716 Round Bars that meet the most stringent international standards. Our production facilities employ vacuum induction melting (VIM) and electro-slag remelting (ESR) processes to ensure superior cleanliness, uniform grain structure, and consistent mechanical performance.

Every batch undergoes strict quality testing, including chemical analysis, ultrasonic inspection, tensile and hardness testing, and corrosion resistance evaluation to guarantee optimum performance in the most challenging environments.

Whether you require materials for aerospace turbines, energy plants, or offshore platforms, SASAALLOY delivers precision-engineered Nickel Alloy 716 Round Bars designed for unmatched strength, reliability, and longevity.

With our deep metallurgical expertise and commitment to excellence, SASAALLOY continues to be a trusted global partner for high-performance nickel-based materials.

---

Conclusion

The Nickel Alloy 716 Round Bar is an advanced engineering material that offers an exceptional combination of mechanical strength, thermal stability, and corrosion resistance. Its ability to retain mechanical integrity under extreme temperature and stress makes it ideal for high-temperature industrial and aerospace applications.

By following precise heat treatment procedures such as solution annealing and aging, the alloy achieves the perfect balance of hardness, toughness, and ductility required for critical service environments.

At SASAALLOY, we take pride in supplying Nickel Alloy 716 Round Bars of the highest quality, optimized through advanced processing and rigorous quality control. Whether for jet turbines, power systems, or chemical plants, SASAALLOY provides materials engineered to perform where others fail — ensuring strength, reliability, and long-term durability in every application.