The main difference between Inconel 601 and 625 is that Inconel 601 is a good choice for chemical processing and aerospace because it resists oxidation at high temperatures. Inconel 625 is stronger and more resistant to corrosion in harsh environments like oil and gas. Inconel 625 has a higher nickel content (around 58%) than Inconel 601 (48-55%), and also has a higher tensile strength.
ASTM B444 Inconel 625 Seamless Pipe Manufacturer
We, Zhejiang Xintongda Special Steel (XTD), are a renowned Inconel 625 seamless pipe manufacturer in China. Inconel 625 pipe is a high-performance nickel-chromium-molybdenum alloy. It consists of around 58% nickel, ~20% chromium, approximately 8% molybdenum, and 3.15–4.15% niobium. We produce this pipe in compliance with the ASTM B444 / ASME SB444 standard. It is known for its resistance to corrosion and thermal stability in extreme conditions. This SMLS 625 pipe is an ideal choice for industries like aerospace, chemical processing, marine engineering, and heat treatment. This is because of its unique blend of properties like oxidation resistance and high temperature strength. As a multiple international certified supplier, we supply this pipe that is put through strict destructive and non-destructive tests to ensure it meets important standards for mechanical properties and integrity. We maintain an annual supply capacity of 25000 tons and supply these pipes within a week for stock orders. Production orders can take 15-60 days.
The key specifications of this seamless pipe include:
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Standard
ASTM B444
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OD Range
6-457 mm
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Thickness
1-35 mm
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Length
≤ 18 m
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Technical Data
Technical Data
Alloy 625 Seamless Pipe Manufacturing Process
The manufacturing of Alloy 625 seamless pipe starts by heating a solid round bar of Inconel 625, called a billet to a very high temperature. Then, the hot billet is pushed through a hot extruded to make a hollow shell. After that, the shell goes through a series of machines that roll and stretch it until it is the right size and thickness. Heat treatment and pickling are done to the metal to keep it strong and resistant to rust. Lastly, the pipes are cut to the right length and checked for strength and quality. To learn about how we make our seamless pipes in detail, visit this page.
Features of Inconel 625 Seamless Pipe
Alloy 625 pipes have 6 characteristics that make them a preferred choice for demanding environments. These include seamless construction, high temperature resistance, oxidation resistance, corrosion resistance, mechanical strength, weldability, and easy fabrication.
- Seamless construction: This pipe is manufactured without a welded seam. The seamless construction makes the structure stronger and better able to handle pressure. It is also less likely to fail and doesn't corrode at the seams. This makes it perfect for applications where leaks are not tolerated.
- High-temperature resistance: Inconel 625 pipe maintains its high strength and integrity at extreme temperatures (up to 1800°F or 982°C). This is due to its thermal stability and chemical composition. However, for applications where extreme heat exposure is the main concern, Inconel 601 Seamless Pipe is preferred.
- Oxidation Resistance: A protective, passivating oxide layer forms on the pipe when the material is exposed to heat. This offers excellent resistance to oxidation and scaling in high-temperature, oxygen-rich environments.
- Corrosion Resistance: UNS N06625 pipe is very resistant to multiple corrosive media, such as strong acids, alkalis and saltwater. The high molybdenum content makes it better at protection against localised attacks like pitting and crevice corrosion.
- Mechanical Strength: The strength of these pipes is due to solid solution strengthening by molybdenum and niobium additions to the nickel-chromium alloy. This gives the pipe superior tensile strength and exceptional resistance to fatigue and creep, even under high stress and pressure conditions.
- Weldability and Fabrication: Despite its high strength the pipe has excellent weldability and can be readily fabricated using a standard process. This ease of joining and forming allows the formation of complex piping systems and components.
Inconel 625 Pipe Equivalent Material
The equivalent designation of Inconel 625 pipe is UNS N06625. Some other equivalents include GB NS336, NCF 625 and Werkstoff 2.4856. The table below explains these equivalent materials clearly.
| GRADE | UNS | GB | JIS | ISO | DIN/EN | GOST | |
| ISC | NEW | ||||||
| Inconel 625 | N06625 | - | NS336 | NCF625 | - | 2.4856 | - |
Inconel 625 Pipe Grade Standard
We ensure that each of our Inconel 625 pipes follows strict international standards. This ensures the material’s performance, composition, and integrity worldwide.
| Pipe Seamless | ASTM B444, ASTM B829, ASME SB 444 |
| Pipe Welded | ASTM B705, ASTM B775, ASME SB 705 |
| Tube Seamless | ASTM B444, ASME SB444 |
| Tube Welded | ASTM B704, ASME SB 704 |
100% Certified Testing & Documentation
Each of our pipes comes with full traceability and quality assurance. We provide the following test reports for verification:
- EN 10204 3.1 and EN 10204 3.2 Material Test Certificates (MTC)
- Raw Materials Certificate
- 100% PMI
- Heat Treatment Charts
- Third-Party Inspection Report
- Surface roughness and size measurement
- Manufacturer Test Certificate (Impact Testing, Flattening, Flare, Bend, Hardness, Intergranular, Pitting Corrosion, Grain size, ET, UT, HT)
- Laboratory Test Certificate from the Government-Approved Lab
Application of Alloy 625 Seamless Pipe
Alloy 625 pipes have 6 major applications.
Chemical processing
Inconel 625 seamless pipe is used for piping systems, reaction vessels, and heat exchangers that handle highly corrosive media, like sulfuric, nitric, and hydrochloric acids. Its high resistance to different organic and mineral acids and superior resistance to pitting and crevice corrosion make it suitable in the chemical processing industry.
Power Generation
This pipe is crucial in power generation in auxiliary nuclear components, boiler tubing, and flue gas desulfurisation systems. Its high-temperature resistance and ability to maintain structural integrity in radiation environments provide safety in conditions with high pressure, high heat, and potential radiation exposure.
Aerospace & Engineering
Inconel 625 pipes are used for thrust reverser systems, jet engine ducting systems, exhaust systems, and hydraulic/fuel lines. Its high tensile strength, creep-rupture strength, and fatigue strength at high temperatures allow parts to handle the extreme thermal and mechanical stress of flight.
Heat Treatment
Alloy 625 pipe is used in heat treatment processes to manufacture furnace hardware like muffles, retort tubes and parts that are exposed to high heat cycles.
Oil & Gas
In the oil & gas industry, this seamless pipe is used for downhole tubulars, control lines, wellhead components, and subsea equipment. Its exceptional resistance to stress-corrosion cracking and corrosion fatigue in sour gas (H₂S) and chloride environments makes it valuable for deep well and offshore applications.
Marine Industry
In the marine environment, the pipe is used in propeller shafts, submarine components like auxiliary propulsion systems, and seawater heat exchangers/piping. The main property that makes it ideal is its excellent resistance to pitting, crevice, and stress corrosion cracking. This prevents premature failure in constantly submerged, saline conditions.
Frequently Asked Questions
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What is the difference between Inconel 601 and 625?
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What sizes are available for Inconel 625 seamless pipes?Inconel 625 seamless pipes are available in Outside Diameters ranging between 6–457 mm, Thickness Range from 1-35 mm, and maximum length up to 18 m.
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Can Zhejiang Xintongda Special ship Inconel pipes internationally?Yes, we can ship international shipments of Inconel pipes worldwide.
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What is Inconel 625 Pipe?Inconel 625 pipe is a nickel-chromium-molybdenum superalloy (UNS N06625). Seamless versions are constructed without a welded seam, offering superior pressure handling. It is known for its high strength, corrosion resistance, and exceptional performance at elevated temperatures. It is one of the grades of Inconel seamless pipes.