High-Temperature & Special Alloy Solutions

High-Temperature & Special Alloy Solutions

Heat-resistant and corrosion-resistant alloys — supplied to the designation on your drawing, with equivalency confirmed in writing before production.

When a Special Alloy Is the Answer

Some components are defined less by their geometry than by what they have to survive: sustained elevated temperature, thermal cycling, a corrosive medium, or a combination of all three. In those conditions the grade carries as much of the specification as the drawing does, and substituting a conventional carbon or low-alloy steel is not a cost saving — it is a different part with a shorter service life.

We manufacture components in nickel-based and other heat- and corrosion-resistant alloys, selected to the service conditions stated for the application.

Typical Application Directions

  • Components in prolonged contact with elevated-temperature process media
  • Parts subject to repeated thermal cycling, where oxidation resistance governs service life
  • Corrosive environments where a stainless grade is insufficient for the duty
  • Special alloy requirements specified by the original equipment drawing

Grade Designations

The same alloy is designated differently under different standards systems. Two frequently specified nickel-based grades are given below.

Common name UNS EN / Werkstoff Composition designation
Inconel 718 N07718 2.4668 NiCr19NbMo
Inconel 625 N06625 2.4856 NiCr22Mo9Nb

On Equivalent Grades

Customers in different regions specify the same alloy under different systems, and the terminology is not used consistently across markets. This is a documentation problem rather than a metallurgical one, and it is resolved before production rather than after.

  • We supply to the designation on your drawing. If it states a UNS, EN, composition, JIS or GB designation, material is supplied and certified to that designation.
  • Where an equivalent is requested, we confirm in writing what is being matched — chemical composition, mechanical properties, heat-treatment condition, or service behaviour. Standards that are frequently treated as interchangeable are close, but their composition ranges and acceptance conditions are not identical.
  • Heat-treatment condition is part of the specification. Solution annealed, aged and stress-relieved conditions produce different properties from the same grade, so the required condition is taken from the drawing.

Inconel 718 — Typical Composition

The following is given as an indication of the grade. The composition actually supplied and certified is the one specified on your drawing and in the order documentation.

Element Typical range (wt %) Element Typical range (wt %)
Nickel (Ni) 50.00 – 55.00 Titanium (Ti) 0.65 – 1.15
Chromium (Cr) 17.00 – 21.00 Aluminium (Al) 0.20 – 0.80
Niobium + Tantalum (Nb+Ta) 4.75 – 5.50 Cobalt (Co) ≤ 1.00
Molybdenum (Mo) 2.80 – 3.30 Carbon (C) ≤ 0.08
Iron (Fe) Balance Manganese (Mn) ≤ 0.35
Silicon (Si) ≤ 0.35 Phosphorus (P) ≤ 0.015
Sulfur (S) ≤ 0.015 Boron (B) ≤ 0.006
Copper (Cu) ≤ 0.30  

Mechanical Properties

Mechanical properties depend on heat-treatment condition, section size and sampling direction, and are taken from the standard and condition stated on the drawing. Typical room-temperature values for solution-treated and aged material are given below, as an indication only.

Property Typical value Basis
Tensile strength, Rm ≥ 1275 MPa (185 ksi) Solution treated and aged
Yield strength, Rp0.2 ≥ 1035 MPa (150 ksi) Solution treated and aged
Elongation ≥ 12 % Solution treated and aged
Reduction of area ≥ 15 % Solution treated and aged
Hardness ≥ 331 HB Solution treated and aged

Values vary with section thickness and heat-treatment condition. Where your drawing or specification states ASME SB 637 or another standard, material is supplied and certified to the edition and condition specified. Values above are indicative and do not replace the applicable standard.

Manufacture and Verification

Special alloys are formed and machined to the route stated in the order documentation. Melting records and heat-treatment records are retained against heat number, and an inspection report is issued per shipment, to the drawing and the applicable standard.

Whether a part is acceptable is settled by the drawing and the technical parameters stated on it — that is what production and acceptance are measured against.

Products are supplied for civil and industrial applications only.

Related pages

Industry Solutions · Materials & Processes · Manufacturing Capabilities · Forged Components · Inspection & Testing · International Standards

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