Q1: What are the material grades corresponding to UNS N08800, N08810, N08825, and N06625?
A1:
UNS N08800 = Incoloy 800
UNS N08810 = Incoloy 800H / 800HT
UNS N08825 = Incoloy 825
UNS N06625 = Inconel 625They are all nickel‑based alloys but differ in composition, high‑temperature strength, and corrosion resistance.
Q2: What is the main difference between Incoloy 800, 800H, and 825?
A2: Incoloy 800 is designed for general high‑temperature oxidation and creep resistance. 800H has controlled carbon and grain size for stronger creep performance at high temperatures. Incoloy 825 adds molybdenum and copper, greatly improving resistance to pitting, crevice corrosion, and acidic media like sulfuric and phosphoric acid.
Q3: How does Inconel 625 (N06625) differ from the Incoloy 800 series?
A3: Inconel 625 contains high molybdenum and niobium, offering extremely high strength, excellent corrosion resistance in seawater, acids, and chloride environments, and superior high‑temperature performance. Incoloy 800 series focus more on heat resistance and cost efficiency, while 625 is used in more severe corrosive and high‑stress conditions.
Q4: What are the typical applications of these four nickel alloys?
A4:Incoloy 800/800H: furnace tubes, heating elements, boiler tubes, petrochemical reformer tubes
Incoloy 825: acid processing, flue gas desulfurization, seawater equipment, heat exchangers
Inconel 625: offshore components, gas turbines, aerospace parts, high‑corrosion piping, fasteners
Q5: What common characteristics do these nickel alloys share?
A5: All have excellent high‑temperature stability, good mechanical properties, outstanding resistance to oxidation and corrosion, good weldability and formability, and long service life in harsh industrial environments. They are widely used in chemical, petrochemical, power, marine, and aerospace fields.
