Specifications

Composition and properties

Phosphorus and sulphur limits as given in the standards.

Values for solution-annealed material as given in ASTM B575.

The most requested product has its own page: Hastelloy C276 sheets and plates.

Solid plate, clad plate or lining

Hastelloy can be used in three ways in equipment. Solid plate is used for smaller vessels, internals, agitators and parts where both sides see the process. Clad plate – a carbon steel backing with a Hastelloy layer bonded by explosion welding or roll bonding – is used for large pressure vessels and columns, where the backing carries the pressure and the cladding resists corrosion. Thin sheet is used as a lining ("wallpapering") on carbon steel ducts, stacks and scrubbers in flue gas desulphurisation and waste incineration, welded to the steel in overlapping strips. Each method needs suitable material thickness and surface condition, so please tell us how the sheet or plate will be used.

Fabrication notes

Hastelloy sheet and plate form well cold but work-harden, so heavy forming may need intermediate solution annealing; hot forming must be followed by solution annealing and rapid cooling. Welding uses matching filler metal, low heat input and very clean joints. Plasma, laser or water-jet cutting is preferred, with thermally cut edges dressed before welding. Store material away from carbon steel and protect finished surfaces from contamination.

Ordering

Please give the alloy and UNS number, specification, thickness, width, length, quantity, the intended use (solid, cladding, lining) and any supplementary tests or inspection.

Why Hastelloy for chemical equipment

The C-type alloys combine high nickel, molybdenum, chromium and tungsten to resist both oxidising and reducing corrosion, pitting and crevice corrosion and chloride stress corrosion cracking. This versatility is why they are used in multi-purpose pharmaceutical and fine-chemical plants, where one reactor may see many different chemistries, and in pollution-control equipment, where acid condensate, chlorides and fluorides concentrate. Because Hastelloy is an expensive material, the design usually limits its use to the surfaces that need it, using clad plate or lining over carbon steel where possible.

Ordering for clad equipment

For explosion-clad or roll-bonded plates, the Hastelloy cladding layer and the carbon steel backing are ordered to their own specifications, and the bond is tested to a cladding standard. For weld overlay, Hastelloy filler metal is used rather than plate. For loose linings, thin sheet is ordered with close flatness tolerance so that strips fit and weld cleanly. In each case, the material certificate of the Hastelloy layer should be traceable to its heat, so that the corrosion-resistant surface can be verified.

Applications and related products

Hastelloy sheets and plates are used for chemical and pharmaceutical reactors, heat-exchanger tube sheets and channels, flue gas desulphurisation scrubbers, ducts and stacks, pulp bleaching equipment, pickling tanks, waste incinerators and sour-gas equipment. To complete a Hastelloy project we also supply Hastelloy pipes and tubes, Hastelloy round bars, Hastelloy flanges, Hastelloy pipe fittings and Hastelloy fasteners. Other plate and sheet materials are on the plates and sheets pages, and alloy guidance on the Hastelloy page.