Inconel 718 heat exchanger bar is a precipitation-hardened nickel-chromium-iron superalloy bar specially optimized for high-performance heat exchanger manufacturing. It combines exceptional high-temperature strength, superior thermal fatigue resistance and excellent corrosion resistance, making it the material of choice for heat exchange equipment operating under extreme cyclic temperature and pressure conditions.
As a premium raw material for critical heat exchanger components, Inconel 718 bar maintains stable mechanical properties up to 700℃, effectively resisting thermal shock, vibration fatigue and corrosive media attack. It significantly extends the service life of heat exchangers and reduces unplanned downtime in aerospace, nuclear power and high-end chemical industries.
| Item | Details |
|---|---|
| Executive Standards | 1. International Material Standards: ASTM B637, AMS 5662, AMS 5663, DIN 17752, EN 2.4668, ISO 6208
2. Heat Exchanger Specific Standards: ASME SB-637, TEMA (Tubular Exchanger Manufacturers Association) Class R standards 3. Quality System Certification: ISO 9001, ISO 14001, OHSAS 18001, AS9100 (Aerospace Grade) 4. Testing Standards: ASTM E8 (Tensile), ASTM E23 (Impact), ASTM G48 (Corrosion), ASTM E2439 (Eddy Current), ASTM A450 (Hydrostatic), ASTM E466 (Fatigue) |
| Material Grade | 1. Main Grade: Inconel 718 (Heat Exchanger Grade, Precipitation Hardened)
2. International Designations: UNS N07718, W.Nr. 2.4668, EN 2.4668 3. Equivalent Grades: GB GH4169, JIS NW7718, fully compatible with all global high-end heat exchanger manufacturing standards |
| Chemical Composition (Weight %) | 1. Nickel (Ni): 50.00 – 55.00
2. Chromium (Cr): 17.00 – 21.00 3. Iron (Fe): 14.00 – 18.00 4. Molybdenum (Mo): 2.80 – 3.30 5. Niobium + Tantalum (Nb+Ta): 4.75 – 5.50 6. Titanium (Ti): 0.65 – 1.15 7. Aluminum (Al): 0.20 – 0.80 8. Carbon (C): ≤0.08 9. Manganese (Mn): ≤0.35 10. Silicon (Si): ≤0.35 11. Phosphorus (P): ≤0.015 12. Sulfur (S): ≤0.015 13. Copper (Cu): ≤0.30 |
| Mechanical Properties (Solution Annealed & Aged State) | 1. Tensile Strength: ≥1240 MPa
2. 0.2% Yield Strength: ≥860 MPa 3. Elongation (δ5): ≥15% 4. Reduction of Area (ψ): ≥30% 5. Hardness (HRC): 32 – 40 6. High-Temperature Tensile Strength (650℃): ≥900 MPa 7. High-Temperature Tensile Strength (700℃): ≥750 MPa 8. Fatigue Strength (10⁷ Cycles): ≥550 MPa 9. Thermal Fatigue Resistance: No cracking after 2000 cycles between 20℃ and 650℃ 10. Corrosion Rate: ≤0.02mm/year in 3.5% NaCl solution (25℃) |
| Dimensional Tolerance (Heat Exchanger Grade Precision) | 1. Diameter Tolerance: Precision Grade (≤50mm): ±0.015mm; Standard Grade (50-100mm): ±0.02mm; Heavy Section (100-200mm): ±0.03mm
2. Length Tolerance: Fixed Length (1m-6m): ±0.2mm/m; Maximum Full-Length Tolerance: ≤0.8mm; Custom Length up to 16m available 3. Roundness: ≤0.01mm (≤50mm); ≤0.015mm (50-100mm); ≤0.02mm (100-200mm) 4. Wall Thickness Uniformity (for finished tubes): ≤±0.015mm 5. Surface Finish: Ra ≤0.8μm standard, optional polished finish Ra ≤0.4μm for critical applications |
| Heat Exchange Working Conditions (Key Focus) | Inconel 718 bar is specifically engineered to perform in the most demanding heat exchange environments where conventional alloys fail:
1. Aerospace Industry: Operates reliably in temperatures from -253℃ to 700℃ and pressures up to 250 bar. Ideal for aircraft engine heat exchangers, auxiliary power units (APUs) and environmental control systems (ECS), where it withstands extreme thermal cycling and vibration 2. Nuclear Power Industry: Resists radiation, high-temperature high-pressure water and boric acid solutions. Used in nuclear reactor cooling systems, steam generators and spent fuel pool heat exchangers, with a design life of 60+ years 3. Chemical Processing Industry: Withstands aggressive media including concentrated acids, alkalis and organic solvents at temperatures up to 650℃. Suitable for high-pressure reactor heat exchangers, fertilizer production equipment and petrochemical refining units 4. Oil & Gas Industry: Resists sour gas (H₂S and CO₂) and high-salt brine environments. Used in deepwater offshore platform heat exchangers, subsea production systems and natural gas processing plants 5. Power Generation Industry: Maintains stable performance in supercritical steam conditions up to 650℃. Used in ultra-supercritical power plant heat exchangers, waste heat recovery systems and gas turbine cooling systems 6. Defense Industry: Used in naval ship nuclear power systems, submarine heat exchangers and missile propulsion systems, where reliability under extreme conditions is critical 7. Cyclic Operation Performance: Exceptional thermal fatigue resistance allows it to withstand frequent start-stop cycles, making it ideal for peaking power plants and intermittent industrial processes |
| Tube Bundle, U Bend Tube & Condenser Tube (Key Focus) | Inconel 718 bar is the primary raw material for manufacturing high-performance heat exchanger tubes and tube bundles for critical applications:
1. Straight Heat Exchanger Tubes: The most common form, used in shell-and-tube heat exchangers for high-temperature high-pressure applications. Inconel 718 straight tubes feature uniform wall thickness, high dimensional accuracy and excellent creep resistance, ensuring efficient heat transfer and long service life. Available in diameters from 6mm to 114mm and lengths up to 16m 2. U Bend Tubes: Critical components of U-tube heat exchangers, widely used in nuclear power plants and aerospace applications. Inconel 718 U bend tubes can be formed with bend radii from 1.5D to 10D without cracking or significant wall thinning (≤4% thinning). After bending, they undergo full non-destructive testing and stress relief to ensure integrity. Ideal for applications requiring thermal expansion compensation 3. Condenser Tubes: Specifically designed for power plant condensers, naval ship condensers and industrial refrigeration systems. Inconel 718 condenser tubes have smooth inner surfaces that reduce fouling and improve heat transfer efficiency. They are resistant to erosion-corrosion caused by high-velocity fluid flow and thermal shock 4. Evaporator Tubes: Used in industrial evaporators, desalination plants and cryogenic systems. Inconel 718 evaporator tubes resist scaling and corrosion from brine solutions and cryogenic fluids, maintaining consistent performance over long periods 5. Finned Tubes: Available with integral or welded fins for enhanced heat transfer. Inconel 718 finned tubes are ideal for high-temperature gas cooling applications in power generation and chemical processing 6. Complete Tube Bundles: We provide custom tube bundle assembly services, including precision tube cutting, bending, end finishing, finning and bundle assembly. Our tube bundles are designed to exact customer specifications and undergo comprehensive performance testing before delivery, ensuring perfect fit with heat exchanger shells and tube sheets 7. Quality Assurance: All tubes and tube bundles undergo 100% hydrostatic testing, eddy current testing, ultrasonic testing and dimensional inspection, meeting ASME and TEMA standards for critical heat exchanger manufacturing |
| Surface Quality (Key Focus) | Surface quality is critical for heat exchanger performance, as surface defects can initiate corrosion, reduce heat transfer efficiency and cause premature failure. Our Inconel 718 bar undergoes rigorous surface treatment and inspection processes:
1. Standard Surface Treatment: All bars are supplied in the solution annealed and pickled condition, which removes oxide scale and produces a uniform, corrosion-resistant passive film. This treatment ensures optimal corrosion resistance in most industrial applications 2. Optional Surface Treatments: – Passivation: Enhances the natural passive film, providing additional corrosion protection in aggressive environments. Performed in accordance with ASTM A967 standards – Electropolishing: Produces a smooth, mirror-like surface with Ra ≤0.2μm, ideal for food, pharmaceutical and sanitary applications where hygiene and cleanability are critical – Mechanical Polishing: Available in various grades from Ra 0.8μm to Ra 0.05μm, reducing fouling and improving heat transfer efficiency by up to 12% – Shot Blasting: Creates a uniform matte surface, improving paint adhesion for coated applications – Pickling and Passivation: Combined treatment for maximum corrosion resistance in harsh chemical environments 3. Defect Control Standards: All bars are 100% visually inspected by trained technicians using magnifying equipment. Surface defects including scratches, pits, cracks, inclusions, seams and laps are strictly controlled. Any defect deeper than 0.03mm is rejected or reworked to meet quality standards 4. Surface Cleanliness: After processing, all bars are thoroughly cleaned with alkaline cleaners and deionized water to remove oil, grease, debris and residual acids. They are then dried and wrapped in protective film to prevent contamination during transportation and storage 5. Special Requirements: We can provide custom surface treatments and quality standards according to customer specifications, including aerospace-grade surface finish requirements and nuclear industry cleanliness standards |
| Straightness (Key Focus) | Straightness is a critical parameter for Inconel 718 bar used in heat exchanger tube manufacturing, as poor straightness can lead to assembly difficulties, stress concentration, reduced heat transfer efficiency and premature tube failure:
1. Standard Straightness Guarantee: Our standard heat exchanger grade Inconel 718 bar has a straightness of ≤0.15mm/m, with a maximum full-length straightness error of ≤0.4mm for 6m long bars. This is significantly better than the industry standard of ≤0.3mm/m 2. Precision Straightening Process: All bars undergo multi-pass precision straightening using state-of-the-art CNC hydraulic straightening machines. The straightening process is computer-controlled to ensure consistent accuracy and avoid introducing internal stresses that could lead to deformation during subsequent processing or heat treatment 3. Advanced Straightness Inspection: Each bar is individually inspected for straightness using high-precision laser straightness measuring equipment with an accuracy of ±0.001mm. The inspection results are recorded and included in the material test report for full traceability 4. Custom Straightness Options: For high-precision applications such as nuclear power plant heat exchangers and aerospace engine components, we can provide bars with straightness as low as ≤0.1mm/m upon request 5. Importance for Heat Exchangers: Excellent straightness ensures that tubes can be easily inserted into heat exchanger tube sheets without forcing, which prevents damage to the tubes and tube sheets. It also ensures uniform spacing between tubes, maximizing heat transfer efficiency and reducing flow-induced vibration that can cause premature tube failure. Additionally, straight tubes experience less stress during operation, extending their service life |
| Eddy Current Testing (ET) (Key Focus) | Eddy current testing is a non-destructive testing method used to detect surface and near-surface defects in Inconel 718 bar. It is an essential quality control step for heat exchanger applications where even minor defects can lead to catastrophic failures and costly downtime:
1. Testing Standards: All eddy current testing is performed in strict accordance with ASTM E2439, ASME V Article 6 and TEMA standards. The testing equipment is calibrated daily using standard reference blocks with artificial defects of known size and depth 2. 100% Full Coverage Inspection: Every inch of the bar surface is inspected, including the entire length, ends and transition areas. The testing is performed at a controlled speed of 0.5-1.5m/s to ensure thorough inspection and accurate defect detection 3. Detection Capability: Our advanced multi-frequency eddy current testing equipment can detect surface and near-surface defects as small as 0.08mm in depth, including cracks, pits, inclusions, seams, laps and wall thickness variations. It can also detect changes in material properties such as hardness and conductivity that could affect performance 4. Testing Process: Each bar passes through a multi-coil eddy current array, which generates a magnetic field and detects changes in electrical conductivity caused by defects. Any detected defect is automatically marked on the bar with paint, and its location, size and severity are recorded in the test report 5. Acceptance Criteria: Only bars with no detectable defects exceeding the acceptance level are approved for delivery. Any bar with defects exceeding the specified limits is rejected and destroyed to prevent it from entering the supply chain 6. Documentation: A detailed eddy current test report is provided for each batch of bars, including test parameters, calibration records, defect locations and acceptance criteria. All test records are retained for a minimum of 15 years for full traceability 7. Significance: Eddy current testing ensures that only defect-free material is used in heat exchanger manufacturing, preventing costly leaks, equipment failures, production losses and potential environmental damage. It is particularly important for critical applications in aerospace and nuclear power where safety is paramount |
| Hydrostatic Testing & Fixed Length (Key Focus) | Hydrostatic testing verifies the pressure resistance and structural integrity of Inconel 718 bar and finished tubes, while precision fixed length cutting ensures perfect fit in heat exchanger assemblies:
1. Hydrostatic Testing Standards: Performed in accordance with ASTM B444, ASME B31.3 and TEMA standards. The test pressure is calculated as 1.5 times the design working pressure, with a minimum test pressure of 42MPa (6000psi) for all heat exchanger grade material. For high-pressure applications, test pressures up to 100MPa are available 2. Testing Procedure: Each bar or finished tube is filled with clean, deionized water with a chloride content of ≤25ppm to prevent corrosion. The pressure is gradually increased to the specified test pressure and held for a minimum of 15 minutes. During this time, the bar is carefully inspected for leaks, bulges, deformation or pressure drop 3. Acceptance Criteria: A bar passes hydrostatic testing only if there is no leakage, no visible deformation and no pressure drop during the entire holding period. Any bar that fails the test is immediately rejected and destroyed 4. Special Testing Options: For ultra-high integrity applications such as nuclear power and aerospace, we can perform helium leak testing with a sensitivity of 1×10⁻⁹ Pa·m³/s, as well as pneumatic testing and burst testing 5. Precision Fixed Length Cutting: We use CNC automatic saws with laser alignment to cut bars to exact customer specifications. Standard fixed lengths include 2m, 3m, 4m, 6m, 9m and 12m. Custom lengths from 0.5m to 16m are available upon request 6. Length Tolerance Guarantee: Fixed length tolerance is ±0.2mm/m, with a maximum full-length tolerance of ≤0.8mm for 6m long bars. This ensures that all tubes in a heat exchanger bundle are the same length, facilitating easy assembly and alignment 7. End Preparation After Cutting: After cutting, the ends are automatically deburred to remove sharp edges and burrs. The cut ends are flat and perpendicular to the bar axis, with a squareness tolerance of ≤0.1mm/m, ensuring proper fit during tube-to-tube sheet joining |
| Tube End Treatment Standards (Key Focus) | Proper tube end treatment is essential for ensuring leak-proof connections and reliable long-term operation of heat exchangers. We offer a full range of standardized and custom tube end treatments to meet all customer requirements:
1. Standard Chamfering: The most common tube end treatment for heat exchanger tubes. We provide 30°-45° chamfers with a 1-2mm flat land, in accordance with ASME B16.25 standards. This treatment facilitates easy insertion into tube sheet holes and prevents damage to the tube sheet during assembly 2. Square Cut Ends: Used for butt welding applications. The ends are cut square and deburred, with a squareness tolerance of ≤0.1mm/m. The end face is machined to ensure a flat, uniform surface for high-quality welding 3. Expanded Ends: Used for tube-to-tube sheet expansion joints. The ends are expanded to a specified diameter using hydraulic or mechanical expanders, with expansion tolerances of ±0.02mm. This creates a tight, leak-proof mechanical bond between the tube and tube sheet. We offer both partial and full expansion options 4. Reduced Ends (Swaged Ends): Used for connecting tubes of different diameters. The ends are swaged or machined to a smaller diameter with a smooth, gradual transition to avoid stress concentration. Available in both concentric and eccentric configurations 5. Threaded Ends: Used for threaded connections. Threads are cut in accordance with NPT, BSPT, BSPP or ISO standards, with thread tolerances of 2A/2B. The threads are deburred and coated with anti-seize compound to prevent galling during assembly 6. Flanged Ends: Used for bolted connections. Flanges are welded to the tube ends in accordance with ASME B16.5 standards. All welds are 100% inspected using ultrasonic testing to ensure integrity 7. Grooved Ends: Used for mechanical coupling connections. Grooves are machined to exact specifications, ensuring proper fit with standard mechanical couplings 8. Beveled Ends: Used for orbital welding applications. Bevels are machined to specified angles (typically 30°-37.5°) with a root face, ensuring high-quality welds 9. Custom End Treatments: We can provide custom tube end treatments according to customer drawings and specifications, including counterboring, threading, flaring and special machining operations |
| Why Choose Us (Emily PIPE) | 1. 20+ Years of Heat Exchanger Material Expertise: We have supplied Inconel 718 materials to over 500 high-end heat exchanger projects worldwide, including aerospace, nuclear power and offshore oil & gas applications
2. Complete International Certifications: Our products hold ASTM, ASME, ISO, TEMA and AS9100 certifications, ensuring compliance with all global heat exchanger manufacturing standards 3. Heat Exchanger-Specific Quality Control: We implement a dedicated quality control process for heat exchanger materials, including 100% non-destructive testing and thermal fatigue verification 4. Full Material Traceability: Every bar comes with a unique heat number and complete traceability documentation from raw material to finished product, meeting the strictest aerospace and nuclear industry requirements 5. Advanced Customization Capability: We can produce custom sizes, lengths, surface finishes and tube end treatments according to your drawings and technical specifications, with lead times as short as 10 days 6. Professional Technical Support: Our team of metallurgical engineers provides expert material selection guidance, heat treatment parameters, welding procedures and machining recommendations for Inconel 718 heat exchanger applications 7. Global One-Stop Service: We handle everything from material selection and production to international shipping and customs clearance, with reliable logistics partners ensuring on-time delivery to any location worldwide |
| Inquiry Guidance Words | 1. If you need Inconel 718 heat exchanger bar for your critical project, please send us your specific requirements including dimensions, quantity, required certifications, heat treatment condition and delivery date, and we will provide a detailed quotation within 12 hours
2. For any questions about material properties, non-destructive testing, tube end treatments or application guidance for Inconel 718 heat exchangers, our industry specialists are available to assist you promptly 3. Emily PIPE is your trusted partner for high-performance heat exchanger alloy materials. Contact us today to discuss how we can support your next project with reliable, cost-effective solutions |
| Supplementary Information | 1. Comprehensive Test Reports: Each batch comes with a full Material Test Report (MTR), including chemical composition, mechanical properties, heat treatment records, non-destructive testing results and corrosion resistance data
2. Professional Packaging: We use anti-corrosion wrapping, wooden crates and steel strapping to protect products during long-distance transportation, with clear identification and traceability labels 3. Urgent Order Support: We maintain a large inventory of standard Inconel 718 bar sizes in solution annealed condition, enabling us to fulfill urgent orders within 5-7 days 4. Small Batch Production: We support small batch orders for prototype development, equipment repairs and spare parts, with no minimum order quantity for standard sizes 5. After-Sales Service: We provide lifetime technical support for all our products, including on-site assistance for material-related issues and replacement parts for warranty claims 6. Sustainability: All our products are 100% recyclable, and we are committed to reducing our environmental impact through sustainable manufacturing practices and energy-efficient production processes |