ASME SB407 seamless alloy 800 pipe is based on a nickel-iron-chromium system that with excellent high-temperature stability, corrosion resistance, and good processing properties, it is widely used in extreme operating conditions such as petrochemicals, power generation, and nuclear power industries. HT PIPE is a astm b407 uns n08800 pipe supplier with 15+ export experience. Contact us for more information and quotes for free!
chemical composition of alloy 800 pipe
The alloy contains 30.0%-35.0% nickel (Ni), 19.0%-23.0% chromium (Cr), and at least 39.5% iron (Fe), forming the basic framework of the alloy. In addition, 0.15%-0.60% titanium (Ti) and 0.15%-0.60% aluminum (Al) are added, with the total content of titanium and aluminum controlled between 0.30%-1.20%, to form stable carbides and improve structural stability at high temperatures. the carbon (C) content is strictly limited to a maximum of 0.10%, and impurities such as sulfur (S) and phosphorus (P) are strictly limited to below 0.015% to ensure the purity and processing plasticity of the alloy.
incoloy n08800 pipe High-Temperature Performance
Incoloy 800 Pipe exhibits excellent high-temperature stability, with a service temperature up to 1100℃. It maintains excellent creep resistance and structural integrity even at temperatures above 600℃. At a high temperature of 816℃, its tensile strength can still maintain about 70% of its room temperature strength. in high-temperature endurance tests at 700℃ and 200MPa pressure, the continuous working time is no less than 100 hours.
alloy n08800 pipe Mechanical Properties
After solution treatment, Incoloy 800 Pipe exhibits stable mechanical properties at room temperature: tensile strength is no less than 500MPa, yield strength is no less than 210MPa, and elongation is no less than 30%. some specifications can reach a tensile strength of 600MPa, a yield strength of 275MPa, and an elongation of 45%, combining both strength and toughness. Its hardness is controlled at HB≤180, possessing good machinability, and its strength can be further improved through cold work hardening.
astm b407 incoloy 800 seamless pipe Corrosion Resistance
In high-temperature oxidizing, carburizing, and nitriding atmospheres, the dense oxide film formed by chromium effectively prevents the intrusion of corrosive media.
In corrosive media containing sulfur and chlorine, its corrosion resistance far exceeds that of 304 stainless steel. In a seawater environment at 80°C with 50,000 ppm Cl⁻, the annual corrosion rate is extremely low.
In a hydrogen-containing environment (4 MPa hydrogen partial pressure, 450°C), its resistance to hydrogen-induced cracking is 8-10 times higher than that of ordinary stainless steel. In addition, this alloy also possesses good resistance to chloride ion stress corrosion, with a critical stress of no less than 250 MPa.
Production Process of Incoloy 800 Pipe
asme sb407 seamless alloy 800 pipe Melting Process
To ensure material purity, Incoloy 800 pipes generally use a dual process of vacuum induction melting (VIM) + electroslag remelting (ESR). This process can strictly control the gas content in the alloy to extremely low levels: oxygen (O) content ≤ 50 ppm, nitrogen (N) content ≤ 150 ppm, effectively reducing internal defects such as pores and inclusions, and improving the material's hot workability and corrosion resistance.
alloy n08800 welded pipe Forming Process
The forming process of Incoloy 800 pipes is divided into two categories: hot working and cold working. Hot working mainly includes hot rolling and hot extrusion, with the processing temperature controlled in the range of 1100-900°C, and the deformation amount maintained at 30-70% to obtain a uniform austenitic structure.
Cold working is suitable for the precision forming of thin-walled pipes (wall thickness ≤ 1 mm), mainly using the cold drawing process, which can achieve a pipe diameter tolerance of ±0.1 mm, a wall thickness tolerance of ±5%, and a straightness of ≤1.5 mm/m, meeting the needs of high-precision equipment such as compact heat exchangers.
alloy 800 welded tube Welding and Heat Treatment Process
In welded pipe production, it is recommended to use ERNiCr-3 welding wire and the GTAW (TIG) welding process. The purity of the shielding gas should be ≥99.995%, and the interpass temperature should be controlled at 100-150°C.
After welding, a solution treatment at 1065℃±15℃ is mandatory, with a cooling rate of ≥55℃/min to ensure complete dissolution of carbides and eliminate the welding sensitization zone. The welded joint must pass RT Level II radiographic testing.
For cold-worked pipes, solution treatment is also required at a temperature of 1100-1175℃, followed by rapid cooling to ensure uniform material properties.
incoloy 800 tubing Core Specifications
Outer diameter range: 6.00mm-914.4mm, including seamless pipes with outer diameters covering 1/8″NB-24″NB and ERW welded pipes with outer diameters covering 1/8″NB-36″NB.
Wall thickness range: 0.3mm-50mm, corresponding to various wall thickness grades such as SCH 5, SCH 10, SCH 20, SCH 40, SCH 80, XXS, etc.
Length: Available in single random lengths, double random lengths, and standard lengths of 0-12m, or customized according to customer requirements.
Pipe end forms include plain ends, beveled ends, and threaded ends. Surface treatments include annealing and pickling (AP), bright annealing (BA), and polishing. For special purpose pipes, the inner surface is electropolished to a roughness Ra≤0.8μm.
