Hastelloy C-276 Pipe for Severe Corrosion Service

Hastelloy C-276 pipe, also identified as UNS N10276, is a nickel-molybdenum-chromium alloy developed for demanding chemical processing and highly corrosive service. Its high molybdenum and chromium content provides strong resistance to pitting, crevice corrosion, and a wide range of reducing and oxidizing media.

Unlike general-purpose stainless steel pipe, Hastelloy C-276 is normally selected when the process environment itself is the main design concern. Chlorides, wet chlorine, acidic solutions, sulfur-containing compounds and mixed chemical streams can create corrosion conditions where conventional stainless grades are no longer a reliable choice.

Hastelloy C-276 Pipe Specifications

Item

Specification

Alloy

Hastelloy C-276

Seamless Pipe

ASTM B622 / ASME SB622

Welded Pipe

ASTM B626 / ASME SB626

Outside Diameter

6–630 mm, or customized

Wall Thickness

0.5–50 mm, or customized

Length

5.8 m / 6 m / 11.8 m / 12 m / Customized

Heat Treatment

Solution Annealed

Surface

Annealed & Pickled / Bright / Customized

Element	Composition, %
Nickel (Ni)	Balance
Chromium (Cr)	14.5–16.5
Molybdenum (Mo)	15.0–17.0
Tungsten (W)	3.0–4.5
Iron (Fe)	4.0–7.0
Cobalt (Co)	≤ 2.5
Manganese (Mn)	≤ 1.0
Vanadium (V)	≤ 0.35
Silicon (Si)	≤ 0.08
Carbon (C)	≤ 0.01
Copper (Cu)	≤ 0.50

Property	Typical Requirement
Tensile Strength	≥ 690 MPa
Yield Strength, 0.2% Offset	≥ 283 MPa
Elongation	≥ 40%
Hardness	According to applicable specification

Why C-276 Is Used in Difficult Corrosion Environments

Hastelloy C-276 was developed for environments where corrosion can occur in several forms at the same time.

Its chemistry gives the alloy a useful combination of:

Resistance to pitting and crevice corrosion
Good resistance to localized corrosion in chloride-containing media
Resistance to many oxidizing and reducing chemicals
Good resistance to stress corrosion cracking
Good weldability compared with many highly alloyed materials
Useful performance in wet chlorine-containing environments
Resistance to many sulfur-bearing process streams

The alloy is particularly useful when the process cannot be described simply as either "acidic" or "chloride-containing." Industrial process streams can contain several aggressive components simultaneously, and this is where C-276 is often considered.