Aleación C276

La Aleación 276 (UNS N10276) es una aleación de níquel – molibdeno – cromo – hierro – tungsteno que se encuentra entre las aleaciones más resistentes a la corrosión que están disponibles actualmente. Su alto contenido de molibdeno le imparte resistencia a la corrosión localizada como las picaduras. Su bajo nivel de carbono minimiza la precipitación de carburos durante el proceso de soldadura para mantener la resistencia al ataque intergranular en las zonas afectadas por el calor de las uniones soldadas.

La Aleación 276 también tiene una buena resistencia a altas temperaturas y resistencia moderada a la oxidación, aunque eventualmente forma precipitados a altas temperaturas que la hacen quebradiza.

Alloy C276 nickel alloy plate (UNS N10276) is a nickel-molybdenum-chromium-iron-tungsten alloy which is among the most corrosion-resistant alloys currently available. The high molybdenum content imparts resistance to localized corrosion such as pitting. The low carbon minimizes carbide precipitation during welding to maintain resistance to intergranular attack in heat affected zones of welding joints.

Alloy C276 nickel alloy plate also has good high temperature strength and moderate oxidation resistance although the alloy will eventually form embrittling high temperature precipitates.

General Properties

Alloy C276 nickel alloy plate (UNS N10276) is an austenitic nickel-molybdenum-chromium alloy with a small addition of tungsten. It is one of the premier corrosion resistant materials available for process industries. Alloy C276 nickel alloy plate has excellent corrosion resistance in both oxidizing and reducing environments.

The combination of the high molybdenum and chromium content, along with the addition of tungsten, make Alloy C276 nickel alloy plate highly resistant to chloride stress corrosion cracking, pitting, crevice corrosion and general corrosion.

Alloy C276 nickel alloy plate can operate in oxidizing atmospheres up to 1900oF (1038oC), however, the alloy lacks sufficient chromium content to operate successfully in the most strongly oxidizing environments like hot, concentrated nitric acid.

The low carbon content of Alloy C276 nickel alloy plate enables the alloy to be utilized in the as-welded condition. It cannot be hardened by heat treatment, but can be hardened by cold working. The alloy has a higher work-hardening rate than the austenitic stainless steels which should be taken into consideration.

Alloy C276 nickel alloy plate can be easily welded and processed utilizing standard shop fabrication practices for austenitic stainless steels and nickel based alloys.

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Chemical Analysis

Weight % (all values are maximum unless a range is otherwise indicated)

Mechanical Properties

Typicals Values at 68°F (20°C)

Corrosion Resistance

Alloy C276 nickel alloy plate is one of the premier corrosion resistant materials that performs exceptionally well in both oxidizing and reducing environments. It resists chloride stress corrosion cracking, pitting, crevice and general corrosion. The alloy is also resistant to carbide precipitation during welding enabling it to be utilized in the as-welded condition.

In chemical processing applications, the alloy has exceptional resistance to sulfuric, hydrochloric, formic, acetic and phosphoric acids. Alloy C276 nickel alloy plate performs well in environments containing acid chlorides, solvents and acetic anhydride, The alloy is one of the few grades that withstands wet chlorine gas, hypochlorite and chlorine dioxide solutions.

Alloy C276 nickel alloy plate is highly resistant to concentrated solutions of oxidizing salts including iron and copper chloride. It also performs well in seawater, especially under crevice conditions where other frequently used alloys such as stainless steel, Alloy 400 and Alloy 625 fail.

The operating conditions of flue gas desulfurization systems offer a challenging environment for corrosion resistant materials. Scrubber liquors and gas condensates often contain chlorides. Alloy C276 nickel alloy plate nickel alloy plate has been shown to withstand higher chloride levels than other grades before the onset of localized corrosion in these systems.

Alloy C276 nickel alloy plate is used extensively in the recovery and processing of sour natural gas which contains hydrogen sulfide along with carbon dioxide and chlorides. Carbon and alloy steels cannot withstand this corrosive environment. They are subject to failure by sulfide stress cracking or stress corrosion cracking. The rich chemistry of Alloy C276 nickel alloy plate makes it resistant to sour environments even at high temperatures in deep wells.

Corrosion Tests* in Hydrogen Fluoride Gas.

Test Duration, 36 Hours. Temperature 932-1112°F (500-600°C)

* 7 lb HF per hour at 4 psig was passed through a laboratory furnace for hydroflourination of metal oxides

Corrosion-resistance of nickel alloys in four 24-hour tests in boiling acetic acid

* (Pren) = %CR + 1.5 (%Mo + %W + %Nb) + 30 (%N)

Maximum Pitting or Crevice Attack, mils (MM), in FGD Scrubber Slurry^a

^a 6-month exposure at 126°F (62°C), pH 5.5, 5000 ppm chlorides
^b Perforated.

NOTE: The information and data in this product data sheet are accurate to the best of our knowledge and belief, but are intended for informational purposes only, and may be revised at any time without notice. Applications suggested for the materials are described only to help readers make their own evaluations and decisions, and are neither guarantees nor to be construed as express or implied warranties of suitability for these or other applications.