Inside high-pressure chemical reactors, the lining serves as your final line of defense. For procurement managers and chemical engineers handling high-temperature phosphoric, sulfuric, or organic acids, localized pitting is a major pain point.
At Gnee Alloy, we help you completely eliminate these risks. As experts in high-temperature corrosion resistance, we are dedicated to providing solutions that ensure structural integrity and zero leakage.
Click to get a quote for Inconel 625 products
Inconel 600 vs 625 vs 718: How to Choose the Right Nickel Alloy for Your Project
Inconel 600 vs 625 vs 718: How to Choose the Right Nickel Alloy for Your Project
Choose Inconel 600 for high-temperature oxidation resistance; Inconel 625 for harsh corrosive environments and ease of welding; and Inconel 718 for extremely high mechanical strength. The optimal choice depends entirely on your project's temperature, stress limits, and environmental conditions.
What are the disadvantages of Inconel 625?
Disadvantages: High cost-due to its complex composition and high production costs, the price of Inconel 625 is significantly higher than that of many other materials. Difficult to machine-Inconel 625 possesses high toughness, which makes machining challenging and requires specialized tools and processes.
Inconel 600 vs 625 vs 718 at a Glance
| Property | Inconel 600 | Inconel 625 | Inconel 718 |
|---|---|---|---|
| UNS Number | N06600 | N06625 | N07718 |
| Main Elements | 72% Ni, 14-17% Cr | 58% Ni, 20-23% Cr, 8-10% Mo | 50-55% Ni, 17-21% Cr, Nb, Mo, Ti, Al |
| Max Service Temp | ~1093°C | ~982°C | ~704°C |
| Tensile Strength | ~655 MPa | ~930 MPa | ~1240 MPa (aged) |
| Corrosion Resistance | Excellent oxidation & carburization | Excellent pitting/crevice resistance | Good general corrosion resistance |
| Typical Applications | Heat exchangers, furnaces, nuclear | Marine, chemical, aerospace weldments | Turbine discs, fasteners, high-strength parts |
| Price Level | $ (Lowest) | $$ | $$$ (Highest) |
Inconel 600/625/718 description
Inconel 600 (UNS N06600)
Inconel 600 is a standard engineering material suitable for applications requiring corrosion and heat resistance. Its balanced nickel-chromium composition provides excellent high-temperature oxidation resistance, as well as good resistance to carburization and chloride-ion stress corrosion cracking.
Key Characteristics
Excellent oxidation resistance at temperatures up to 1093°C
Good corrosion resistance in carburizing and nitriding atmospheres
Maintains high mechanical stability across a wide temperature range
Good formability and weldability
Non-magnetic with excellent dimensional stability
Product Forms Available from Gnee Alloy
We stock and supply Inconel 600 in the form of sheet, plate, bar, pipe (seamless and welded), wire, and coil. All materials can be supplied with EN 10204 3.1 Material Test Certificates (MTC) and third-party inspection reports upon request.
Inconel 718 (UNS N07718)
Inconel 625 is a nickel-chromium-molybdenum alloy with the addition of niobium. The combined effect of molybdenum and niobium imparts high strength to the alloy without the need for heat treatment, while chromium provides excellent resistance to oxidation and corrosion in aggressive media.
Key Characteristics of Inconel 718
Possesses the highest tensile and yield strengths among these three alloys
Exhibits excellent creep resistance at temperatures up to 704°C
Demonstrates good weldability as a precipitation-hardened alloy
Offers exceptional oxidation and corrosion resistance at moderate temperatures
Maintains good mechanical properties under cyclic thermal loading
Inconel 625 (UNS N06625)
Inconel 625 is a nickel-chromium-molybdenum alloy with the addition of niobium. The synergistic effect of molybdenum and niobium enables it to maintain high strength without heat treatment, while chromium provides excellent resistance to oxidation and corrosion in various media.
Key Characteristics
Excellent resistance to pitting, crevice corrosion, and intergranular corrosion
High strength maintained from room temperature up to 980°C
Superior fatigue strength and resistance to stress corrosion cracking
Excellent weldability (even for heavy-section components)
Good resistance to chloride-ion stress corrosion
inconel 600/625/718 Chemical Composition Comparison (wt%)
| Element | Inconel 600 (UNS N06600) | Inconel 625 (UNS N06625) | Inconel 718 (UNS N07718) |
|---|---|---|---|
| Nickel (Ni) | ≥ 72.0 (Balance) | ≥ 58.0 (Balance) | 50.0 – 55.0 |
| Chromium (Cr) | 14.0 – 17.0 | 20.0 – 23.0 | 17.0 – 21.0 |
| Iron (Fe) | 6.0 – 10.0 | ≤ 5.0 | Balance |
| Molybdenum (Mo) | - | 8.0 – 10.0 | 2.8 – 3.3 |
| Niobium + Tantalum (Nb+Ta) | - | 3.15 – 4.15 | 4.75 – 5.50 |
| Cobalt (Co) | ≤ 1.0 | ≤ 1.0 | ≤ 1.0 |
| Carbon (C) | ≤ 0.15 | ≤ 0.10 | ≤ 0.08 |
| Manganese (Mn) | ≤ 1.00 | ≤ 0.50 | ≤ 0.35 |
| Silicon (Si) | ≤ 0.50 | ≤ 0.50 | ≤ 0.35 |
| Copper (Cu) | ≤ 0.50 | - | ≤ 0.30 |
| Titanium (Ti) | - | ≤ 0.40 | 0.65 – 1.15 |
| Aluminum (Al) | - | ≤ 0.40 | 0.20 – 0.80 |
Room-temperature mechanical properties of Inconel 600/625/718
| Property | Inconel 600 (Annealed) | Inconel 625 (Annealed) | Inconel 718 (Aged) |
|---|---|---|---|
| Tensile Strength, UTS (MPa) | ≥ 550 – 690 | ≥ 827 – 1034 | ≥ 1240 – 1275 |
| Yield Strength, YS 0.2% (MPa) | ≥ 240 – 310 | ≥ 414 | ≥ 1030 – 1034 |
| Elongation at Break (%) | ≥ 30 – 45 | ≥ 30 | 12 – 20 |
| Hardness (HB) | 150 – 200 | 200 – 250 | 330 – 380 |
| Modulus of Elasticity (GPa) | ~ 214 | ~ 207 | ~ 207 |
Click to download the Inconel 625 alloy PDF datasheet
Physical Properties of Inconel 600/625/718
| Property | Inconel 600 | Inconel 625 | Inconel 718 |
|---|---|---|---|
| Density (g/cm³) | 8.47 | 8.44 | 8.19 |
| Melting Range (°C) | 1354 – 1413 | 1290 – 1350 | 1260 – 1336 |
| Thermal Conductivity (W/m·K) | 14.9 | 9.8 | 11.4 |
| Coefficient of Thermal Expansion (×10⁻⁶/°C, 20-100°C) | 13.3 | 12.8 | 13.0 |
| Magnetic Properties | Non-magnetic | Non-magnetic | Non-magnetic |
Comparison of Corrosion Resistance of Inconel 600, 625, and 718
| Corrosion Type | Inconel 600 | Inconel 625 | Inconel 718 |
|---|---|---|---|
| General Corrosion | Good | Excellent | Good |
| Pitting / Crevice (PREN) | ~ 30 | ≥ 45 | ~ 35 |
| Chloride SCC | Good (resistant) | Immune | Immune (high Ni) |
| High-Temperature Oxidation | Excellent | Excellent | Good |
| Reducing Acids | Moderate | Excellent | Moderate |
| Oxidizing Acids | Good | Excellent | Good |
| Sour Service (NACE MR0175) | Limited | Yes (annealed) | Limited (requires special heat treatment) |
Overview of Key Applications for Inconel 600, 625, and 718
| Industry | Inconel 600 | Inconel 625 | Inconel 718 |
|---|---|---|---|
| Aerospace | Gas turbine components | Combustion chambers, exhaust ducts | Turbine discs, blades, high-strength fasteners |
| Oil & Gas / Marine | Limited | Subsea flowlines, wellhead equipment, seawater systems | Downhole tools, BOP components |
| Chemical Processing | Caustic alkali, furnace components | Reactors, FGD systems, acid service | Limited (valves, fasteners) |
| Nuclear | Steam generator tubing | Waste processing | Control rod mechanisms |
| Heat-Treating | Furnace components, retorts | Limited | Limited |
Contact our experts to recommend the right alloy for your project
Why Choose Gnee as Your Nickel-Based Alloy Supplier
✅️AS9100 Certified Quality: Every meter of material is governed by the highest aviation and pressure vessel management protocols.
✅️Total Traceability: Every order includes a full EN 10204 3.1 Mill Test Certificate (MTC) documenting PREN and NDT results.
✅️Direct Factory Price: Eliminate middleman markups and secure the best rates for bulk maintenance or new vessel builds.
Gnee Alloy inconel 625 Certificate
📦 Packaging and Shipping
All Nickel Based Alloy products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Gnee Alloy 625 Alloy Product Packing
Contact us for the latest export price quote for 625 Alloy
FAQ
Q1: Can Inconel 625 be used for Weld-Overlay cladding instead of plates?
A: Yes, but Lining Plates are often the more Cost-effective Solution for large surface areas. Lining allows for faster installation and easier localized replacement during MRO shutdowns compared to grinding out cladding.
Q2: Is your GH3625 interchangeable with Inconel 625 for my reactor?
A: Absolutely. GH3625 is the technische designation used within the Chinese national standard for the exact same metallurgical system as UNS N06625. We provide certificates proving total chemical and mechanical parity.
Q3: How do you handle shipping to Europe or the Middle East?
A: We work with global carriers to provide secure, insured delivery to major industrial hubs within 5-7 business days for stock items, ensuring your turnaround schedule is met.
Q4: Do you offer trial quantities for coupon testing?
A: Yes. We support Innovation and R&D by offering Flexible MOQs on our in-stock inventory for site corrosion tests.
