Hastelloy C-276 (UNS N10276): Round Bars, Seamless Tubes & Plates — Technical Data Sheet

Quick Answer: What Is Hastelloy C-276?

Hastelloy C-276 (UNS N10276 / W.Nr. 2.4819) is a premier nickel-molybdenum-chromium superalloy formulated for service environments demanding high mechanical strength and exceptional corrosion resistance. Its high performance stems from the solid-solution strengthening from molybdenum (15–17%), chromium (14.5–16.5%), and tungsten (3.0–4.5%) within its stable nickel-chromium-molybdenum matrix. Its low carbon content (≤0.01%) minimizes carbide precipitation and preserves corrosion resistance in the as-welded condition. Operating efficiently from cryogenic temperatures up to a maximum oxidation service of approximately 650°C (1200°F), Hastelloy C-276 is widely utilized in severe chemical processing, flue-gas desulfurization (FGD), and sour-gas oilfield service.

Product Overview

At the atomic level, its face-centered cubic (FCC) austenitic matrix providing excellent ductility and toughness. Its primary advantage is outstanding resistance to both oxidizing and reducing acids, combined with exceptional resistance to localized corrosion, which yields superior resistance to pitting, crevice corrosion, and stress-corrosion cracking in chloride-containing and acidic media.

Shanghai Hangbo Alloy Group Co., Ltd., established in 2012, stands as a top-tier global manufacturer and supplier of Hastelloy C-276. Operating under a certified ISO 9001:2015 quality management system, we command an export network covering 50+ countries. Our portfolio contains high-precision centerless ground round bars, heavy industrial plates, and high-pressure seamless tubing engineered for critical industrial applications. By managing carbon distribution and grain refinement during melting and forging, we ensure our material provides robust structural performance under severe stress. Every order comes with 100% material traceability and certified documentation, ensuring compliance with strict global engineering standards.

Executive Standards

Shanghai Hangbo Alloy Group Co., Ltd. manufactures Hastelloy C-276 in strict compliance with international technical specifications:

Note: Shanghai Hangbo executes 100% confirmation of chemical compliance using Optical Emission Spectroscopy (OES) for every melt lot.

Chemical Composition

The corrosion-resistant profile of Hastelloy C-276 depends on its exact chemical balance. Chromium ensures high-temperature oxidation resistance, while molybdenum safeguards against localized pitting in chloride environments.

Mechanical Properties

Hastelloy C-276 delivers excellent design allowable stresses. The data below outlines typical properties for annealed stock.

Room-Temperature Mechanical Properties

High-Temperature Performance: Strength Retention Analysis

Hastelloy C-276 retains remarkable mechanical properties under thermal stress, establishing its credentials as a critical superalloy:

How Hastelloy C-276 Is Produced

Round Bar & Forging

• 1. Double Melting (VIM + ESR): ensures high purity and uniform chemistry across large ingots.
• 2. Hot Forging: ingots are forged on hydraulic presses to refine grain structure.
• 3. Solution Annealing: rapid water quenching after heating preserves the single-phase solid solution.
• 4. Precision Grinding: bars are centerless-ground to h8/h9 tolerances.

Seamless Tube & Pipe

• 1. Billet Piercing & Extrusion: forged rounds are pierced into hollows.
• 2. Cold Pilgering / Drawing: multi-pass reductions ensure uniform wall thickness.
• 3. Bright Annealing: hydrogen-atmosphere annealing produces an oxide-free finish.
• 4. Defect Testing: 100% Eddy Current and hydrostatic testing.

Sheet, Plate & Strip

• 1. Hot Rolling: four-high mill processing with controlled reduction.
• 2. Cold Rolling: precise gauge control within ±0.05 mm.
• 3. Leveling: tension leveling for flatness.
• 4. Pickling: nitric-hydrofluoric bath to restore passive surface.

Industry Applications: Solving Engineering Challenges

Chemical Processing

C-276 is the industry standard for reactors, heat exchangers, and piping handling hydrochloric, sulfuric, and phosphoric acids, as well as chloride-containing process streams.

Flue Gas Desulfurization (FGD)

Its resistance to wet SO₂/SO₃ environments makes it ideal for scrubber liners, absorber towers, and reheater components.

Oil & Gas

Used in sour-gas (H2S) service, acid-gas removal units, and downhole completion equipment.

Pulp & Paper

C-276 handles aggressive bleaching chemicals such as chlorine dioxide and hypochlorite.

Quality Assurance: 7-Stage Zero-Defect Inspection Protocol

Shanghai Hangbo Alloy Group Co., Ltd. deploys an intensive inspection matrix to support a zero-defect mandate across all production lines:

• 1. Chemical verification: OES analysis on every melt batch alongside handheld PMI validation on finished products ensures composition parameters match executive limits.
• 2. Ultrasonic Testing (UT): Performed per ASTM A388 standards across all bars and plates to confirm the absence of inner voids, seams, or gas inclusions.
• 3. Eddy Current Testing (ET): Applied 100% to tubes following ASTM E309 protocols to check surface and sub-surface continuity.
• 4. Hydrostatic Pressure Verification: Tubes undergo hydrostatic tests up to 10,000 PSI to verify wall integrity under high-pressure parameters.
• 5. Mechanical Destructive Testing: Tensile, offset yield, elongation, and Brinell hardness examinations are executed per heat lot to verify strength criteria.
• 6. Dimensional Metrology Check: Digital calipers and computerized laser sensors measure geometry, guaranteeing all diameter, wall, and length tolerances match orders.
• 7. Visual and Microstructure Audit: Surface quality checks are paired with metallographic microscope tests to evaluate grain size (ASTM E112) and phase homogeneity.

All items leave our facilities accompanied by ISO 9001:2015 certification and EN 10204 3.1 Mill Test Certificates. Third-party inspection options through SGS, TUV, or Bureau Veritas (BV) are organized upon customer request.

Frequently asked questions