Incoloy Alloy Pipe/Tube is a tubular product made from a family of nickel-iron-chromium-based superalloys primarily known for their balanced combination of high-temperature stability and excellent aqueous corrosion resistance. These alloys balance Nickel (to resist chloride stress-corrosion cracking) and Chromium (to resist oxidation and general corrosion), maintaining structural stability and resistance to oxidation and carburization at elevated temperatures. Incoloy pipe is widely used in chemical processing (such as handling sulfuric and phosphoric acids with Grade 825), the power industry (heat exchangers, furnace tubing), and the oil and gas industry (piping exposed to high temperatures and corrosive media), serving as a critical component requiring strength, oxidation resistance, and defense against aqueous corrosion.

Incoloy Alloy Pipe Description

Incoloy alloys are a family of nickel-iron-chromium alloys characterized by their excellent balance of high-temperature strength, resistance to oxidation/carburization, and moderate aqueous corrosion resistance at a competitive cost. Incoloy tube and pipe products are widely used in industrial heating, power generation, and chemical/petrochemical processing.

Core Incoloy Alloy Tube/Pipe Grades Comparison

The Incoloy series is typically divided between high-temperature/high-strength grades (800 series) and specialized aqueous corrosion-resistant grades (825, 25-6MO).

General Performance Characteristics of Incoloy Alloy Tube and Pipe

1. High-Temperature Service

Oxidation and Carburization Resistance: Grades 800 and 800H/HT exhibit outstanding resistance to scaling and attack in industrial heating and furnace atmospheres due to the stable nickel-chromium oxide layer.

Creep and Stress Rupture: The controlled composition and annealing of 800H/HT ensure high strength retention under stress at extremely elevated temperatures, making them suitable for pressure tubing.

2. Aqueous and Chemical Corrosion

Acid Resistance (825, 25-6MO): High Ni, Mo, and Cu content (in 825) provide strong resistance to non-oxidizing acids, while the high Mo in 25-6MO ensures durability against chlorides, pitting, and crevice corrosion.

Stress Corrosion Cracking (SCC): The high nickel content provides good resistance to chloride-ion SCC.

3. Fabrication and Workability

Weldability: Most Incoloy grades are readily weldable. Grades 800 and 825 are solid-solution alloys that are generally easy to weld without special post-weld treatments for corrosion.

Formability: The alloys are ductile and can be easily drawn and bent to produce seamless or welded tubing and piping for complex layouts.

Application Value of Incoloy Tube and Pipe

Incoloy tubing is chosen when superior high-temperature performance or specific resistance to corrosive acids is required, balancing performance and material cost:

Petrochemical and Refining: Cracking coils, pyrolysis tubes, transfer piping, and radiant tube assemblies (Grade 800H/HT).

Power Generation: Superheater and reheater tubing in conventional boilers and heat exchanger tubing in nuclear plants (Grade 800).

Chemical Processing: Piping, heat exchangers, and vessels handling sulfuric acid, phosphoric acid, and aggressive chemical streams (Grade 825, 25-6MO).

Oil and Gas: Downhole service tubing and high-strength components in sour wells (Grade 925).