Material Family

Nickel-Iron-Chromium Austenitic Alloy (Solid-Solution Strengthened) Coil/Strip

The coiled form of the versatile, economical high-temperature alloy.

Common Forms & Tempers

Forms: Cold Rolled Coil (Strip), Annealed Pickled Coil.
Temper: Annealed (Soft) for forming; Hard/Spring Temper for applications requiring high-temperature spring properties (e.g., clips, retainers).

For 800H/HT, the coil must be supplied in the annealed condition with a controlled coarse grain structure (ASTM 5 or coarser) to develop specified creep strength.

Chemical Composition (Typical wt.%)

Ni: 30.0 - 35.0
Cr: 19.0 - 23.0
Fe: ≥ 39.5 (Balance)
Al: 0.15 - 0.60
Ti: 0.15 - 0.60
C:
• 800: ≤ 0.10
• 800H: 0.05 - 0.10
• 800HT: 0.06 - 0.10 (plus Al+Ti: 0.85-1.20)

High Iron (Fe) content makes it more economical. Controlled C, Al, Ti in H/HT grades are critical for high-temperature strength.

Mechanical Properties (By Temper, Room Temp)

Annealed (Soft):
• Tensile: 520 - 690 MPa
• Yield: 205 - 345 MPa
• Elongation: 30 - 45%
Hard Temper (Typical):
• Tensile: 700 - 900 MPa
• Yield: 550 - 750 MPa
• Elongation: 10 - 20%

Good ductility and moderate strength. The key advantage is strength retention at high temperatures, especially for 800H/HT.

Coil Physical Specifications (Typical)

Thickness: 0.10mm - 3.0mm (0.004" - 0.125")
Width: 10mm - 600mm (0.4" - 24")
Coil I.D.: 300mm, 405mm, 508mm (12", 16", 20")
Coil Weight: 50kg - 2000kg

Precision slitting and gauge control are essential for producing consistent fin stock, clips, and formed parts.

Key Performance Attributes

• Excellent resistance to oxidation, carburization, and sulfidation.• Good resistance to chloride stress corrosion cracking and aqueous corrosion.• 800H/HT: Superior and predictable creep rupture strength at high temperatures.• Good formability and weldability in the annealed condition.

An excellent all-rounder coil for high-temperature, non-load-bearing and moderate-load components in the petrochemical and power industries.

Key Standards (Strip/Coil)

ASTM B409 / ASME SB-409 (Sheet, Strip, and Plate), ASTM B407 (Mandatory for 800H/HT grain size control), DIN 1.4876

For 800H/HT, compliance with ASTM B407 (coarse grain anneal) is essential to guarantee high-temperature properties.

Typical Coil Applications

• Heat Exchangers: Fin stock, strip for spiral heat exchangers, air preheater elements.
• Industrial Furnaces: Conveyor belt links, radiant tube support clips, furnace rolls, thermocouple protection sheaths.
• Power Generation: Spacer strips, seal strips in superheaters.
• Chemical Processing: Components for reforming furnace atmospheres, cracker tube hangers (800H/HT).

The most common application is in tubular and plate heat exchangers and continuous furnace systems across multiple industries.