HASTELLOY^® C-22HS^®

Principal Features

HASTELLOY^® C-22HS^® alloy (N07022) is the premier nickel-chromium-molybdenum, corrosion-resistant material for oil and gas industry use. Cold working of the alloy at levels between 30 and 65% result in high room temperature yield strengths. It exhibits exceptional resistance to sour gas environments and is NACE/ISO approved.

Product Forms

C-22HS^® alloy is available in the form of plate, sheet, strip, billet, bar, wire, pipe, and tube. Round products in the form of solid bars are available up to 10″ with various amounts of cold work to achieve high strength and toughness by simultaneously retaining the excellent corrosion resistance of the alloy.

Oil & Gas Applications

The data in this document is believed to be useful for applications in the oil & gas industry, or other industries which may require an alloy with excellent corrosion resistance and strength levels higher than “standard” HASTELLOY^® C-22^® alloy. For additional oil and gas information on C-22HS^®, please click here.

Available in Three Very High-Strength Conditions

Early testing of C-22HS^® alloy was focused on material in the annealed + age-hardened condition where the material was annealed at 1975°F (1079°C) and age-hardened at 1300°F (704°C)/16h/Furnace cool (FC) to 1125°F (607°C)/32h/Air-cool (AC.) In this “standard condition” C-22HS^® alloy will typically have strengths around 100 ksi (690 MPa). While this strength level is almost double of “C-type” alloys in the annealed condition, many oil and gas applications require even greater strength. For this reason, a considerable development effort has been generated on C-22HS^® alloy in three other “very high strength” conditions:

1) Cold Worked

2) Cold Worked + Age-Hardened^A

3) Low Temperature (LT) Annealed^B + Age-Hardened^C

^A1125°F (607°C)/10h/AC ^B1850°F (1010°C) ^C1300°F (704°C)/16h/FC to 1125°F (607°C)/32h/AC

A comparison of yield strengths for the three very high strength conditions is shown below along with that of the annealed and “standard” conditions. Haynes does not recommend use of highly cold worked and aged material because the increase in yield strengths is minimal and the susceptibility to hydrogen embrittlement in severe oil well conditions is increased.

Nominal Composition

Tensile Properties of Cold-worked Material

Average Room Temperature Tensile Properties of Bar
(Cold-worked in the Range 43-47%)

Room Temperature Tensile Properties of Bar as a Function of Diameter and Percentage Cold-work

*Averages from duplicate test samples

Room and Elevated Temperature Tensile Properties of 0.5 in Diameter
Cold-worked (43%) Bar

Room and Elevated Temperature Tensile Properties of 2.375 in Diameter Cold-worked (54%) Bar as a Function of Orientation (Longitudinal and Transverse)

Average Room Temperature Tensile Properties of Tube
(Cold-worked in the Range 52-53%)

Room and Elevated Temperature Tensile Properties of Cold-worked Tube

(3.5 in Diameter by 0.43 in Wall Thickness) (52-53%) as a Function of Orientation

Values are averages from 10 tests
RT= Room Temperature

Statistical Temperature De-rating C-22HS^® Cold-worked Tubing

Impact Strength

C-22HS^® Alloy Room Temperature Charpy V-Notch Impact Test Results

*Average of three tests

Fracture Toughness

Room Temperature ASTM E1820 Tests

4.25 in (108 mm) OD x 2.25 in (57 mm) ID Tube Pre-Cracked Half-T Compact Tension [C(T)] Specimens Located at 120° Increments

Hardness

*Average values HRC= Hardeness Rockwell “C”

Compressive Strength

Room Temperature Compressive Strength of 0.75 in Diameter Cold-worked (44%) Bar and Corresponding Tensile Data

*Average from two tests

Resistance to Sour Gas Environments

Sour Gas Testing – NACE TM0177 Method A Tensile Test, Test Levels II and III, 720 hours, Applied Stress = 100% YS

*Triplicate tests

Sour Gas Testing – NACE TM0177 Method C, 90-Day C-Ring Test,
Test Level VII:  25% NaCl, 500 psi (3.5 MPa) H₂S + 500 psi (3.5 MPa) CO₂, Elemental Sulfur = 1 g/l and 5 g/l**

Test Temperature: 401°F (205°C), Applied Stress = 100% YS
Material Condition: Cold-Worked

*Triplicate tests
**With stirring

Sour Gas Testing – NACE TM0177 Method C, 90-Day C-Ring Test, Test Level VII-Plus: 25% NaCl, 1000 psi (6.9 MPa) H2S + 1000 psi (6.9 MPa) CO2

Test Temperature: 401°F (205°C)
Material Condition: Cold-Worked

Sour Gas Testing – NACE TM0198 Slow Strain Rate Tensile Test, Test Level VII:  25% NaCl,
500 psi (3.5 MPa) H2S + 500 psi (3.5 MPa) CO2, Without (w/o) Elemental Sulfur

Test Temperature: 401°F (205°C)
Material Condition: Cold-Worked

*Air – single test; Level VII w/o S – triplicate tests

Sour Gas Testing – NACE TM0198 Slow Strain Rate Tensile Test, Test Level VII:  25% NaCl,
500 psi (3.5 MPa) H2S + 500 psi (3.5 MPa) CO2, With Elemental Sulfur

est Temperature: 401°F (205°C)
Material Condition: Cold-Worked

*Air – single test; Level VII w/S – triplicate tests

Resistance to Hydrogen Embrittlement

Slow Strain Rate Tensile Test – Cold-worked Material

Resistance to Acids

Corrosion Rates of Cold-worked (40%) Sheet in Aqueous Solutions of Common Acids

*ASTM G-28A = 50% H₂SO₄ + 42 g/l Fe₂(SO₄)₃
**ASTM G-28B = 23% H₂SO₄ + 1.2% HCl + 1% Fe₃Cl + 1% CuCl₂

Dynamic Modulus

High-Cycle Fatigue

Material: 0.5 in Diameter 43% Cold Worked Bar (0.2%YS – 191 ksi, UTS – 196 ksi, %EL – 18, %RA – 66)
Rotating Bend Fatigue Testing, RR Moore Rotating 4-Point Bend
R = -1.0 Stress Ratio, 167 Hz, Room Temperature

Hardness Profile

HRC = Hardness, Rockwell C Scale

HRC= Hardness Rockwell “C”

Thermal Stability

Effects of Thermal Exposure on Tensile Properties of 0.5 in Diameter,

Cold-worked (43%) Bar

AC=Air Cool
RT= Room Temperature
R.A.= Reduction of Area

Effects of Thermal Exposure on Impact Strength of 1 in Diameter, Cold-worked (44%) Bar

AC= Air Cooled
RT= Room Temperature

Resistance of Welds to Sour Gas Environments

Sour Gas Testing – NACE TM0177 Test Levels II and III, Method A, Solution A, Applied Stress = 100% YS, Material Condition: All Weld Metal, As Welded

*Triplicate tests

Sour Gas Testing – NACE TM0198 Slow Strain Rate Tensile, Level VII, Test Environment: 25% NaCl, 500 psi (3.5 MPa) H2S + 500 psi (3.5 MPa) CO2, 401°F (205°C),
Material Condition: All Weld Metal, As Welded

*Air – duplicate tests, Level VII w/o sulfur – triplicate tests
R.A.= Reduction of Area

Sour Gas Testing – NACE TM0198 Slow Strain Rate Tensile, Level VII, Test Environment: 25% NaCl, 500 psi (3.5 MPa) H2S + 500 psi (3.5 MPa) CO2,
Material Condition: All Weld Metal, As Welded, Heat 1

*Air – single test; Test Environment – **duplicate tests, ***triplicate tests

Weld Mechanical Properties

C-22HS^® alloy Room Temperature Transverse Weld Tensile Test Results, As-Welded Condition

C-22HS^® alloy Room Temperature All-Weld-Metal Tensile Test Results,
As-Welded Condition

C-22HS Alloy Weld Metal Charpy V-Notch Impact Test Results,
As-Welded Condition

*Test sample did not break

Specifications

Specifications

Disclaimer

Haynes International makes all reasonable efforts to ensure the accuracy and correctness of the data displayed on this site but makes no representations or warranties as to the data’s accuracy, correctness or reliability. All data are for general information only and not for providing design advice. Alloy properties disclosed here are based on work conducted principally by Haynes International, Inc. and occasionally supplemented by information from the open literature and, as such, are indicative only of the results of such tests and should not be considered guaranteed maximums or minimums.  It is the responsibility of the user to test specific alloys under actual service conditions to determine their suitability for a particular purpose.

For specific concentrations of elements present in a particular product and a discussion of the potential health affects thereof, refer to the Safety Data Sheets supplied by Haynes International, Inc.  All trademarks are owned by Haynes International, Inc., unless otherwise indicated.

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