Hastelloy Sheet Plate

Hastelloy is a family of nickel-based superalloys originally developed by Haynes International (formerly Union Carbide). Despite the common name "Hastelloy steel sheet," Hastelloy is not a steel — it is a nickel-based alloy with chromium and molybdenum.

The defining characteristic of Hastelloy sheet is their exceptional resistance to uniform corrosion, pitting, crevice corrosion, and stress-corrosion cracking in the most aggressive environments: hot contaminated sulfuric acid, hydrochloric acid, wet chlorine, seawater with high chloride, and mixed oxidising/reducing acids.

Hastelloy sheets are grouped into two families by their primary corrosion mechanism:

• "C-series" (C276, C22, C4, C2000): molybdenum-chromium-tungsten-nickel alloys optimised for general corrosion resistance across a wide pH and oxidising spectrum. C-276 is the most widely used grade.

• "B-series" (B2, B3): nickel-molybdenum alloys with virtually no chromium, optimised specifically for hydrochloric acid (HCl) service at all concentrations and temperatures up to the boiling point.

• Other families: "X-series" (Hastelloy X) for high-temperature oxidation resistance (aerospace, gas turbines); "G-series" (G-30, G-35) for nitric and phosphoric acid service.

Available Hastelloy Sheet Grades

Six Hastelloy grades are commonly available in sheet form.

Hastelloy Sheet Types and Product Forms

Hastelloy is available in multiple product forms. "Sheet" specifically refers to material with thickness 0.5mm to 6.35mm (0.020" to 0.250"). Material thicker than 6.35mm is called "plate." The thinner forms (0.05mm to 0.5mm) are called "foil" or "strip."

Standard Sheet Sizes Most Commonly Stocked

Production and Material Standards

Hastelloy sheets are produced to internationally recognised standards. Specifying the correct standard ensures that the material you receive meets the chemistry, mechanical property, and dimensional tolerance requirements for your application.

Mechanical Properties and Physical Data

Sheet Dimensions, Weights, and Tolerances

Hastelloy density is 8.89 g/cm3 (C-276) — approximately 11% heavier than 316L (7.98 g/cm3). Always use the correct density when calculating freight and crane capacity.

Frequently Asked Questions

Q: Is Hastelloy a stainless steel?

A: No. Hastelloy is a nickel-based superalloy (typically 52-58% nickel). Stainless steel is iron-based (typically < 10% nickel). The high nickel content gives Hastelloy its exceptional corrosion resistance.

Q: What is the difference between Hastelloy C-276 and C-22?

A: C22 has higher chromium (22% vs. 15.5%) and lower molybdenum (13.5% vs. 16%), giving it better resistance to oxidising acids (nitric, ferric chloride). C276 has better resistance to reducing acids (sulfuric, hydrochloric). For mixed environments, C22 is preferred. For strongly reducing acids, C276 is preferred.

Q: Can I use Hastelloy C276 in nitric acid (HNO3)?

A: Not recommended. C276 contains 15-17% molybdenum, which forms molybdenum trioxide (soluble in HNO3) and accelerates corrosion. For HNO3 service, use Hastelloy G30 or 304L/316L stainless steel (which are adequate for pure HNO3).

Q: What is the maximum operating temperature for Hastelloy C276 sheet?

A: For corrosion service: up to 1040C (continuous). Above 1040C, sigma phase and mu phase precipitate, reducing corrosion resistance. For high-temperature structural applications (aerospace), use Hastelloy X (up to 1200C).

Q: Can Hastelloy sheets be bent or formed?

A: Yes, but with difficulty. Hastelloy work-hardens rapidly. Bending requires larger bend radii (minimum 2-3x thickness for C276 vs. 1x thickness for 316L). Always anneal after severe cold work.

Q: How do I identify Hastelloy C276 sheet on-site?

A: Use PMI (XRF or OES). Check for: Ni ~ 55-58%, Mo ~ 15-17%, Cr ~ 14.5-16.5%, W ~ 3-4.5%. If you do not have a PMI device, send a sample to a laboratory for OES analysis.

Q: Can I weld Hastelloy C276 to 316L stainless steel?

A: Not recommended. The dissimilar metal weld has high risk of crackng (different thermal expansion, different microstructure). If you must join them, use Inconel 625 (UNS N06625) as a transition piece, or use a flange connection with PTFE gasket.

Q: Why does Hastelloy C276 cost 12-18x more than 304 stainless steel?

A: Nickel (the primary element in Hastelloy) costs 3-4x more than iron. Molybdenum and tungsten (both expensive) add further cost. Processing is also more expensive: Hastelloy requires dedicated tooling (no contamination from carbon steel), and work-hardening increases forming time.