Chemical Processing UNS N10276 High Performance Alloys Easy To Form And Weld

Corrosion resistant alloy UNS N10276, alloy C276, Hastelloy C276 for chemical processing

PRODUCT

Corrosion resistant alloy UNS N10276, alloy C276, Hastelloy C276, Inconel C276 for chemical processing components including heat exchangers, reaction vessels, evaporators, transfer piping and columns, etc.

EQUIVALENT DESIGNATION

NS334, Alloy C276, Hastelloy® C276, Inconel® C276, W.Nr. 2.4819, NiMo16Cr15W(DIN), AWS A5.11, NC17D(France), NiMo16Cr15Fe6W4(ISO)

PRODUCT FORM

Alloy UNS N10276 is available in the form of plate, sheet, strip, billet, round bar, flat bar, hexagon bar, wires, pipes, tubes, pipe fitting, forging, fastener, ring, forging stock and covered electrodes.

Wrought products are supplied in the mill annealed condition, unless otherwise specified.

OVERVIEW

Alloy UNS N10276 (Alloy C276) is known for its corrosion resistance in a wide range of aggressive media. 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 welded joints.

By virtue of extremely low carbon and silicon contents, alloy UNS N10276 is a wrought Ni-Cr-Mo material to alleviate concerns over welding. Like other nickel alloys, it is ductile, easy to form and weld, and possesses exceptional resistance to stress corrosion cracking in chloride-bearing solutions (a form of degradation to which the austenitic stainless steels are prone). With its high chromium and molybdenum contents, it is able to withstand both oxidizing and non-oxidizing acids, and exhibits outstanding resistance to pitting and crevice attack in the presence of chlorides and other halides. Furthermore, it is very resistant to sulfide stress cracking and stress corrosion cracking in sour, oilfield environments.

APPLICATION

UNS N10276 is used in chemical processing, pollution control, pulp and paper production, industrial and municipal waste treatment and the recovery of “sour” natural gas. Applications in air pollution control include stack liners, ducts, dampers, scrubbers, stack-gas re-heaters, fans and fan housings. In chemical processing, the alloy is used for components including heat exchangers, reaction vessels, evaporators, transfer piping and columns.

CHEMICAL COMPOSITION (wt%):

PHYSICAL PROPERTY

Density: 8.89g/cm³

Melting point:1325-1370℃

CORROSION RESISTANCE

Alloy C276 is resistant to general corrosion, stress corrosion cracking, pitting and crevice corrosion in a broad range of severe environments. Its resistance to carbide precipitation during welding maintains corrosion resistance in the heat affected zones of welded joints.

It has exceptional resistance to sulfuric acid and hydrochloric acid. It resists many of the most severe media encountered in chemical processing, including reducing and oxidizing acids, highly oxidizing, neutral, and acid chlorides, solvents, formic and acetic acids, acetic anhydride, wet chlorine gas, hypochlorites, and chlorine solutions. It has excellent resistance to phosphoric acid. At all temperatures below the boiling point and at concentrations lower than 65 wt%, tests have shown corrosion rates of less than 5 mpy (0.13 mm/y).

Alloy C276 exhibits excellent resistance to corrosion by seawater especially under crevice conditions which induce attack in other commonly used materials such as 316 stainless steel, Monel® 400, and Inconel 625.

MECHANICAL PROPERTIES

Typical room temperature tensile properties annealed material

HEAT TREATMENT

Hot forming should be between 1600-2250℉(870-1230℃), with all heavy forming above 2000℉(1090℃). alloy C276 is normally annealed at 2100-2150℉(1150-1175℃) and rapidly cooled such as by water quenching.

FABRICATING

Alloy C276 can be hot forged, hot rolled, hot upset, hot extruded, and hot formed. However, it is more sensitive to strain and strain rates than the austenitic stainless steels, and the hot working temperature range is quite narrow. For example, the recommended start temperature for hot forging is 1232℃(2250℉) and the recommended finish temperature is 954℃(1750℉). Moderate reductions and frequent re-heating provide the best results. The alloy is stiffer than most austenitic stainless steels, and more energy is required during cold forming. Also, alloy C276 work hardens more readily than most austenitic stainless steels, and may require several stages of cold work, with intermediate anneals.

JOINTING

Alloy C276 is very amenable to the Gas Metal Arc Weld (GMAW), Gas Tungsten Arc Weld(GTAW), and Shielded Metal Arc Weld(SMAW) welding processes. Matching filler metals (i.e. solid wires and coated electrodes) are available for these processes.

Alloy C276 has good weldability and can be used as-welded for most applications. INCO-WELD® filler metal and welding electrode 686CPT® can be used to “overmatch” alloy C-276 where enhanced corrosion resistance is required.

Table 26 Corrosion resistance of weldments in alloy C276

STANDARD SPECIFICATION

ASME SB366 / ASTM B366 Fittings

ASME SB462 / ASTM B462 Rod, bar and forging stock

ASME SB472 / ASTMB472 Nickel alloy billet and bar for reforging

ASME SB564 / ASTM B564 Nickel alloy forging

ASME SB574 / ASTMB574 Low carbon nickel alloy rod

ASME SB575 / ASTMB575 Low carbon nickel alloy sheet, plate & strip

ASME SB619 / ASTM B619 Welded Nicke and Nickel-Cobalt alloy pipe and tube

ASME SB622 / ASTM B622 Seamless Nicke and Nickel-Cobalt alloy pipe and tube

ASME SB626 / ASTM B626 Welded Nicke and Nickel-Cobalt alloy pipe and tube

ASME SB 751 / ASTM B751 Welded Tube

ASME SB 775 / ASTM B775 Welded pipe

ASME SB 829 / ASTM B829 Seamless Tube

ASME SB983 / ASTM B983 Precipitation hardened or cold worked seamless nickel alloy pipe and tube

AWS A5.11,ENiCrMo-4 Electrode

TÜV Werkstoffblatt 400

TÜV Kennblatt 320

TÜV Kennblatt 319

NACE MR0175 ISO 15156

COMPETITIVE ADVANTAGE:

(1) More than 50 years experience of research and develop in high temperature alloy, corrosion resistance alloy, precision alloy, refractory alloy, rare metal and precious metal material and products.
(2) 6 state key laboratories and calibration center.
(3) Hundreds of patent technologies.

DESCRIPTION:

BUSINESS TERM