HASTELLOY® alloy C-276 (UNS N10276)


Ni 57.0, Mo 16.0, Cr 15.5, Fe 5.5, W 3.8

 

High Performance Alloys stocks and produces this grade in the following forms: Bar, wire, sheet, plate, coil, fasteners and forgings. Request quote on this grade. See our on-line catalog for sizes stocked

 

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Overview

Nickel-chromium-molybdenum wrought alloy that is considered the most versatile corrosion resistant alloy available. This alloy is resistant to the formation of grain boundary precipitates in the weld heat-affected zone, thus making it suitable for most chemical process applications in an as welded condition. Alloy C-276 also has excellent resistance to pitting, stress-corrosion cracking and oxidizing atmospheres up to 1900°F. Alloy C-276 has exceptional resistance to a wide variety of chemical environments.

 

Characteristics

  • One of the few alloys resistant to wet chloride gas, hypochlorite and chlorine dioxide solutions.
  • Exceptional resistance to strong solutions of oxidizing salts, such as ferric and cupric chlorides.
  • Not prone to grain boundary precipitation in the as welded condition and therefore suitable for many chemical process applications

Applications

  • Digesters and bleach plants in the paper industry.
  • Components exposed to sour gas.
  • Equipment for flue-gas desulfurisation plants.
  • Evaporators, heat exchangers, filters and mixers used in sulfuric acid environments.
  • Sulfuric acid reactors.
  • Organic chloride process equipment.
  • Equipment for processes utilizing halide or acid catalysts.

Some typical applications include equipment components in chemical and petrochemical organic chloride processes and processes utilizing halide or acid catalysts. Other industry applications are pulp and paper (digesters and bleach areas), scrubbers and ducting for flue gas desulfurization, pharmaceutical and food processing equipment.

HASTELLOY Alloy C-276 is a nickel-chromium-molybdenum alloy with universal corrosion resistance unmatched by any other alloy. It has outstanding resistance to a wide variety of chemical process environments including ferric and cupric chlorides, hot contaminated mineral acids, solvents, chlorine and chlorine contaminated (both organic and inorganic), dry chlorine, formic and acetic acids, acetic anhydride, sea water and brine solutions and hypochlorite and chlorine dioxide solutions. Alloy C-276 also resists formation of grain boundary precipitates in the weld heat affected zone making it useful for most chemical processes in the as-welded condition. It has excellent resistance to pitting and stress corrosion cracking.

HASTELLOY Alloy C-276 sheet 0.044" thick in the heat-treated condition at 2050°F, rapid quenched, has an average olsen cup depth of 0.48". C-276 can be successfully fabricated by many methods. The alloy tends to work harden but with the proper care, the alloy is readily hot and cold formed. Complete information on welding, machining and forming is available

Chemistry

Chemical Requirements

Ni

Cr

Mn

Mo

C

Si

Fe

Max

Bal.

16.5

1.0

17.0

0.010

0.08

7.0

Min

14.5

15.0

4.0


Tensile Data

Mechanical Property Requirements

Ultimate Tensile

Yield Strength (0.2% OS)

Elong. in 2 in. (50.8mm) or 4D min,%

R/A

Hardness

Min

100 KSi

41 KSi

40

Max

Min

690 MPa

283 MPa

Max


Specifications

Form

Standard

Metal Type

UNS N10276

Bar

ASTM B574 Din 17752

Wire

Sheet

ASTM B575 Din 17750

Plate

ASTM B575 Din 17750

Fitting

ASTM B366

Forging

ASTM B564

Tube

ASTM B619 ASTM B622 ASTM B626 Din 17751

Pipe
ASTM B619 ASTM B622 ASTM B626 Din 17751
Weld Wire
A5.14 ERNiCrMo-4
Weld Electrode
A5.11 ENiCrMo-4

Din.

2.4819 All Forms





Machining

 

Machinability Ratings

 

Nickel & cobalt base corrosion, temperature and wear-resistant alloys are classified as moderate to difficult when machining, however, it should be emphasized that these alloys can be machined using conventional production methods at satisfactory rates. During machining these alloys work harden rapidly, generate high heat during cutting, weld to the cutting tool surface and offer high resistance to metal removal because of their high shear strengths. The following are key points which should be considered during machining operations:

CAPACITY - Machine should be rigid and overpowered as much as possible.
RIGIDITY - Work piece and tool should be held rigid. Minimize tool overhang.
TOOL SHARPNESS - Make sure tools are sharp at all times. Change to sharpened tools at regular intervals rather than out of necessity. A 0.015 inch wear land is considered a dull tool.
TOOLS - Use positive rake angle tools for most machining operations. Negative rake angle tools can be considered for intermittent cuts and heavy stock removal. Carbide-tipped tools are suggested for most applications. High speed tools can be used, with lower production rates, and are often recommended for intermittent cuts.
POSITIVE CUTS - Use heavy, constant, feeds to maintain positive cutting action. If feed slows and the tool dwells in the cut, work hardening occurs, tool life deteriorates and close tolerances are impossible.
LUBRICATION - lubricants are desirable, soluble oils are recommended especially when using carbide tooling. Detailed machining parameters are presented Tables 16 and17. General plasma cutting recommendations are presented in Table 18.

 

Table 16
RECOMMENDED TOOL TYPES AND MACHINING CONDITIONS
Operations Carbide Tools
Roughing, with severe interruption Turning or Facing C-2 and C-3 grade: Negative rake square insert, 45 degree SCEA1, 1/32 in. nose radius. Tool holder: 5 degree neg. back rake, 5 degree neg. side rake. Speed: 30-50 sfm, 0.004-0.008 in. feed, 0.150 in depth of cut. Dry2, oil3, or water-base coolant4.
Normal roughing Turning or Facing C-2 or C-3 grade: Negative rate square insert, 45 degree SCEA, 1/32 in nose radius. Tool holder: 5 degree neg. back rake, 5 degree neg. side rake. Speed: 90 sfm depending on rigidity of set up, 0.010 in. feed, 0.150 in. depth of cut. Dry, oil, or water-base coolant.
Finishing Turning or Facing C-2 or C-3 grade: Positive rake square insert, if possible, 45 degree SCEA, 1/32 in. nose radius. Tool holder: 5 degree pos. back rake, 5 degree pos. side rake. Speed: 95-110 sfm, 0.005-0.007 in. feed, 0.040 in. depth of cut. Dry or water-base coolant.
Rough Boring C-2 or C-3 grade: If insert type boring bar, use standard positive rake tools with largest possible SCEA and 1/16 in. nose radius. If brazed tool bar, grind 0 degree back rake, 10 degree pos. side rake, 1/32 in. nose radius and largest possible SCEA. Speed: 70 sfm depending on the rigidity of setup, 0.005-0.008 in. feed, 1/8 in. depth of cut. Dry, oil or water-base coolant.
Finish Boring C-2 or C-3 grade: Use standard positive rake tools on insert type bars. Grind brazed tools as for finish turning and facing except back rake may be best at 0 degrees. Speed: 95-110 sfm, 0.002-0.004 in feed. Water-base coolant.
Notes:
1 SCEA - Side cutting edge angle or lead angle of the tool.

2 At any point where dry cutting is recommended, an air jet directed on the tool may provide substantial tool life increases. A water-base coolant mist may also be effective.

3 Oil coolant should be premium quality, sulfochlorinated oil with extreme pressure additives. A viscosity at 100 degrees F from 50 to 125 SSU.

4 Water-base coolant should be premium quality, sulfochlorinated water soluble oil or chemical emulsion with extreme pressure additives. Dilute with water to make 15:1 mix. Water-base coolant may cause chipping and rapid failure of carbide tools in interrupted cuts.

 

Table 17
RECOMMENDED TOOL TYPES AND MACHINING CONDITIONS
Operations Carbide Tools
Facing Milling Carbide not generally successful, C- grade may work. Use positive axial and radial rake, 45 degree corner angle, 10 degree relief angle. Speed: 50-60 sfm. Feed: 0.005-0.008 in. Oil or waterbase coolants will reduce thermal shock damage of carbide cutter teeth.
End Milling Not recommended , but C-2 grades may be successful on good setups. Use positive rake. Speed: 50-60 sfm. Feed: Same as high speed steel. Oil or water-base coolants will reduce thermal shock damage.
Drilling C-2 grade not recommended, but tipped drills may be successful on rigid setup if no great depth. The web must thinned to reduce thrust. Use 135 degree included angle on point. Gun drill can be used. Speed: 50 sfm. Oil or water-base coolant. Coolant-feed carbide tipped drills may be economical in some setups.
Reaming C-2 or C-3 grade: Tipped reamers recommended, solid carbide reamers require vary good setup. Tool geometry same as high speed steel. Speed: 50 sfm. Feed: Same as high speed steel.
Tapping Not recommended, machine threads, or roll-form them.
Electrical Discharge Machining The alloys can be easily cut using any conventional electrical discharge machining system (EDM) or wire (EDM).
Notes:
5 M-40 series High Speed Steels include M-41 , M-42, M-43, M-44, M-45 and M-46 at the time of writing. Others may be added and should be equally suitable.

6 Oil coolant should be a premium quality, sulfochlorinated oil with extreme pressure additives. A viscosity at 100 degree F from 50 to 125 SSU.

7 Water-base coolant should be premium quality, sulfochlorinated water soluble oil or chemical emulsion with extreme pressure additives. Dilute with water to make 15:1 mix.

 

Table 18
Plasma Arc Cutting
Our alloys can be cut using any conventional plasma arc cutting system. The best arc quality is achieved using a mixture of argon and hydrogen gases. Nitrogen gas can be substituted for hydrogen gases, but the cut quality will deteriorate slightly. Shop air or any oxygen bearing gases should be avoided when plasma cutting these alloys.

 

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