Overview

The HAYNES® and HASTELLOY® alloys fall into two main categories:

Corrosion-resistant Alloys (CRA), which are generally used at temperatures below 1000°F, and are able to withstand corrosive liquids.
High-temperature Alloys (HTA), which are generally used above 1000°F, at which temperatures they possess considerable strength and resistance to hot air and/or other hot gases.

The high-temperature alloys can also be sub-categorized according to the mechanism used to provide their strength. Many of the alloys contain significant quantities of atomically-large elements; these provide strength through a mechanism known as solid-solution strengthening. Other HTA materials use a mechanism known as age-hardening (also known as precipitation-hardening) to attain the required strength levels. There is also one age-hardenable, corrosion-resistant alloy.

The heat treatments required to strengthen the age-hardenable materials are normally performed after welding and hot/cold-working, and prior to these heat treatments, there is much in common with the fabrication techniques/parameters employed with the solid-solution strengthened alloys, as long as they are supplied in the annealed condition.

As with the stainless steels and other alloy systems, it is advantageous to have a rudimentary understanding of the metallurgical changes that might occur in the HAYNES® and HASTELLOY® alloys, if exposed to the heat of welding, the high temperatures involved with hot-working, or the effects of annealing after cold-working. If brazing is to be attempted, it is very important to understand how the temperatures involved with brazing might affect the HAYNES® and HASTELLOY® materials, or conversely how subsequent age-hardening (in the case of the age-hardenable alloys) or annealing treatments (in the case of any of the alloys) might affect the brazed joint.

In addition to the general purpose alloys manufactured by Haynes International, there are several special purpose alloys, requiring different fabrication approaches. One is a titanium alloy made only in the form of tubulars, and for which fabrication references are given. One is a high-temperature, nickel-based alloy that requires a nitrogen diffusion treatment to impart strength to the material, and for which there are some specific fabrication issues. The other two are cobalt-based, wear-resistant alloys, one of which is not normally welded or formed; the other is easily welded, but somewhat resistant to cold-working due to a high work-hardening rate.

Haynes International Alloys

High-temperature Alloys (HTA)

High-temperature Alloys (HTA)
Base Solid-Solution Age-Hardenable
Nickel
N, S, W, X
75
214®, 230®
617®, 625, 625SQ®
HR-120®, HR-160®, HR-224®, HR-235®
242®, 244®, 263, 282®
718
R-41
Waspaloy
X-750
Cobalt
25, 188
-
Iron
556®, MULTIMET®
-
Corrosion-resistant Alloys (CRA)
Base Solid-Solution Age-Hardenable
Nickel
B-3®
C-4, C-22®, C-276, C-2000®
G-30®, G-35®
HYBRID-BC1®
C-22HS®
Lightweight Alloy (LA)
Base Age-Hardenable
Titanium Ti-3Al-2.5V
High-temperature Alloy (HTA-NS)
Base Nitrogen-Strengthenable
Cobalt
NS-163®
Wear-resistant Alloy (WRA)
Base -
Cobalt 6B
Wear & Corrosion-resistant Alloy (WCRA)
Base -
Cobalt
ULTIMET®

Wire and Welding Product Forms

wire1

Standard product size range for wire and welding consumables:

  • Loose Coils: 0.030 – 0.187” (0.76 – 4.70mm) diameters
  • Precision Layer Wound Wire: 0.030 – 0.093” (0.76 – 2.40mm) diameters
  • Cut-length Wire: 0.030 – 0.187” (0.76 – 4.70mm) diameters
  • Wire Rod for Redraw: 0.218 – 0.275” (5.50 – 7.00mm) diameters
  • Coated Electrodes: 0.093 – 0.187” (0.187 – 4.70mm) diameters
  • Drum Packs: 0.035 – 0.125″ (0.88 – 3.17mm) diameters. We offer 250 LB – 500 LB drums.

If you require a non-standard size, please contact one of our sales representatives.

wire2Our Wire Products Manufacturing Facility , located in Mountain Home, North Carolina, manufactures finished high-performance alloy wire and welding consumables. The Mountain Home plant is located on approximately 29 acres of land, and includes approximately 100,000 square feet of building space. Finished wire products are also warehoused at this facility.

The Wire Facility receives HASTELLOY® and HAYNES® alloy rod coil from the main manufacturing facility in Kokomo, Indiana. The product is melted in Kokomo, rolled into rod coil, and then shipped to the Wire Products Manufacturing Facility. The majority of the rod coil is 0.218” (5.50mm). The Wire Facility also produces many other nickel alloys and stainless steel grades rod coils from various suppliers throughout the world. The products produced include:

  • Round wire only in MIG, TIG, loose coils, coated electrodes, and spools
  • Sizes from 0.030” to 0.156” for welding products and, as small as, 0.008” in fine wire

Common medical applications include stents, bone drill bits, cerclage cables, guide rods, orthopedic cables and heart valves.

Other wire products for the medical industry:

  • 304V (ASTM F899)
  • 316LVM (ASTM A580, ASTM F138)
  • 420DVM (ASTM A580, ASTM F899)
  • Nickel 200/201/205 (ASTM B160-05)
  • NiCr 80 (ASTM-B-344)

wire4
High-speed, in-line cleaner for finished wire

Manufacturing Equipment

  • 4 Morgan Draw Benches
  • 6 Barcro Intermediate Draw Benches
  • 12 Bull Blocks
  • 32 Fine Wire Drawing Machines
  • 5 Heavy Wire Strand Annealing Lines
  • 5 Fine Wire Strand Annealing Lines
  • 2 Ultrasonic Cleaners
  • 2 Precision Level Winders
  • 6 Straighten and Cut Machines
  • 1 Flag Tag Machine

wire7
The GIMAX Precision Winder produces high-quality layer wound welding spools.
wire9
Rigorous positive material identifications are built into every product.

Certifications and Approvals

wire8
Wire is available in loose coil form in standard diameters.

Hot-working

The HAYNES® and HASTELLOY® alloys can be hot-worked into various shapes; however, they can be more sensitive to the amounts and rates of hot-reduction than the austenitic stainless steels. In addition, the hot-working temperature ranges for the HAYNES® and HASTELLOY® alloys are quite narrow, and careful attention to hot-working parameters is necessary

In developing suitable hot-working practices, particular attention should be paid to the solidus of the alloy in question (the temperature at which the alloy begins to melt), the high strengths of the HAYNES® and HASTELLOY® alloys at elevated temperatures, their high work-hardening rates, and their low-thermal conductivities. Furthermore, their resistance to deformation increases markedly as the temperature falls to the low end of the hot-working range.

Accordingly, hot-working practices that incorporate high (heavy) initial reductions, followed by moderate final reductions, coupled with frequent re-heating, generally yield the best results. In addition, slow deformation rates tend to minimize adiabatic heating and applied force requirements.

*Following any hot-working operation, the HAYNES® and HASTELLOY® alloys should be annealed, to return them to their optimal condition for service, age-hardening (in the case of the age-hardenable alloys), or for further fabrication. Annealing temperatures and techniques are detailed in the heat treatment section.

Melting Temperature Ranges

Melting Temperature Range
Alloy Solidus* Liquidus**
- °F °C °F °C
B-3® 2500 1370 2585 1418
C-4 - -
C-22® 2475 1357 2550 1399
C-22HS® 2380 1304 2495 1368
C-276 2415 1323 2500 1371
C-2000® 2422 328 2476 1358
G-30® - -
G-35® 2430 1332 2482 1361
HYBRID-BC1® 2448 1342 2509 1376
N 2375 1302 2550 1399
ULTIMET® 2430 1332 2470 1354
25 2425 1329 2570 1410
75 2445 1341 2515 1379
188 2400 1316 2570 1410
214® 2475 1357 2550 1399
230® 2375 1302 2500 1371
242® 2350 1288 2510 1377
244® 2480 1360 2550 1399
263 2370 1299 2470 1354
282® 2370 1299 2510 1377
556® 2425 1329 2480 1360
617 2430 1332 2510 1377
625 2350 1288 2460 1349
625SQ® 2350 1288 2460 1349
718 2300 1260 2435 1335
HR-120® 2478 1359 2542 1395
HR-160® 2360 1293 2500 1371
HR-224® 2449 1343 2510 1377
HR-235® 2401 1316 2473 1356
MULTIMET® 2350 1288 2470 1354
R-41 2385 1307 2450 1343
S 2435 1335 2516 1380
W 2350 1288 2510 1377
Waspaloy 2425 132 2475 1357
X 2300 1260 2470 1354
X-750 2540 1393 2600 1427

*Temperature at which alloy starts to melt
**Temperature at which alloy is fully molten

Forging

Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy

The following procedures are recommended for forging of the HAYNES® and HASTELLOY® alloys:

  • Soak billets or ingots at the forging start temperature for at least 30 minutes per inch of thickness. The use of a calibrated optical pyrometer is essential.
  • The stock should be turned frequently to make sure that it is heated evenly. Direct flame impingement on the alloy must be avoided.
  • Forging should begin immediately after withdrawal from the furnace. A short time lapse may allow surface temperatures to drop as much as 100-200°F (55-110°C). Do not raise the forging temperature to compensate for heat loss, as this may cause incipient melting.
  • Moderately heavy reductions (25-40%) are beneficial, to maintain as much internal heat as possible, thus minimizing grain coarsening and the number of re-heatings. Reductions greater than 40% per pass should be avoided.
  • Care must be taken to impart sufficient hot-work during forging to ensure that the appropriate structure and properties are achieved in the final part. For parts with large cross-sections, it is advisable to include a number of forging upsets in the hot-working schedule, to allow for adequate forging reductions. Upset L/D ratios of 3:1 are generally acceptable.
  • Light-reduction finish sizing sessions should generally be avoided. If required, they should be performed at the lower end of the forging temperature range.
  • Do not make radical changes in the cross-sectional shape, such as going directly from a square to a round, during initial forming stages. Instead, go from a square to a “round cornered square”, then to an octagon, then to a round.
  • Remove (condition) any cracks or tears developed during forging. This can be done at intermediate stages, between forging sessions.

Forging/Hot-working Temperature Ranges

Forging/Hot-Working Temperature
Alloy Start Temperature* Finish Temperature**
- °F °C °F °C
B-3® 2275 1246 1750 954
C-4 2200 1204 1750 954
C-22® 2250 1232 1750 954
C-22HS® 2250 1232 1750 954
C-276 2250 1232 1750 954
C-2000® 2250 1232 1750 954
G-30® 2200 1204 1800 982
G-35® 2200 1204 1750 954
HYBRID-BC1® 2250 1232 -
N 2200 1204 1750 954
ULTIMET® 2200 1204 1750 954
25 2200 1204 1750 954
75 2200 1204 1700 927
188 2150 1177 1700 927
214® 2150 1177 1800 982
230® 2200 1204 1700 927
242® 2125 1163 1750 954
244® - -
263 2150 1177 1750 954
282® 2125 1163 1850 1010
556® 2150 1177 1750 954
617 2125 1163 1600 871
625 2150 1177 1600 871
625SQ® - -
718 2050 1121 1650 899
HR-120® 2150 1177 1700 927
HR-160® 2050 1121 1600 871
HR-224® - -
HR-235® 2250 1232 1750 954
MULTIMET® 2150 1177 1700 927
R-41 2150 1177 1850 1010
S 2100 1149 1700 927
W 2240 1227 1800 982
Waspaloy 2150 1177 1850 1010
X 2100 1149 1750 954
X-750 2150 1177 1750 954

*Maximum
**Dependent upon the nature and degree of working

Hot-rolling

Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy

Hot rolling of the HAYNES® and HASTELLOY® alloys can be performed to produce conventional rolled forms, such as bars, rings, and flats. The hot rolling temperature range is the same as that listed above (in the Forging section, under Forging/Hot-working Temperature Ranges).

Moderate reductions per pass (15 to 20 percent reduction in area), and rolling speeds of 200 to 300 surface feet per minute tend to provide good results, without overloading the mill. The total reduction per session should be at least 20 to 30 percent. It is usual to finish at the low end of the hot-working temperature range, since this generally provides the optimum structure and properties.

Care should be taken to ensure that the work piece is thoroughly soaked at the hot working start temperature before rolling. Frequent re-heating may be required during hot-rolling, to keep the temperature of the work piece in the hot working range.

Hot-forming

Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy

The hot-forming of plates into components, such as dished heads is normally performed by cold-pressing or spinning, with intermediate anneals. However, sometimes the size and thickness of the material is such that hot-forming is necessary.

When hot-forming is required, the start temperature (to which the furnace is heated) is approximately mid-way between the annealing temperature (of the alloy in question) and its lower (finish) forging temperature. During hot-forming, the temperature of the piece should not fall below the lower (finish) forging temperature. Re-heating may be necessary to maintain the correct hot forming temperature, and dies should be warmed to avoid excessive chilling of the surfaces.

Other Hot-Working Processes

Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy

The HAYNES® and HASTELLOY® alloys are amenable to several other hot-working processes, such as hot-extrusion and hot-spinning. Impact extrusion should be performed at the solution annealing temperature of the alloy involved. Uniform and accurate temperatures throughout the work-piece are necessary during impact extrusion, and re-strikes should be avoided. The parameters for hot extrusion and hot spinning are specific to the exact nature of the intended work and material. For more information, please contact our technical support team.

Cold-working

The HAYNES® and HASTELLOY® alloys can be readily formed into various configurations by cold-working. Since they are generally stronger, and work harden more rapidly, than the austenitic stainless steels, the application of greater force is normally required to achieve the same amount of cold deformation. The higher yield strengths of the HAYNES® and HASTELLOY® alloys may also result in greater spring-back after cold forming, relative to the austenitic stainless steels. Furthermore, rapid work hardening may necessitate more frequent annealing treatments between forming steps, to attain the final shape. Graphs illustrating the effects of cold-work upon the hardness, yield strength, and ductility of some of the HAYNES® and HASTELLOY® alloys are shown below.

Effect of Cold-work on Hardness Applicable to:

Effect of Cold-Work on Yield Strength:

Effect of Cold-work on Elongation Applicable to:

Generally, as-supplied materials (annealed at the Haynes International mills) have sufficient ductility for mild forming. However, for higher levels of cold deformation, where cracking is a possibility due to a reduction in ductility, a series of successive forming operations is recommended, each followed by an intermediate annealing treatment. Under most circumstances, this should be a solution anneal (the temperatures for which are given in the Heat Treatment section). A final (solution) anneal is recommended after the completion of such successive forming/annealing operations, to restore the material to its optimum condition and properties. This is particularly important for restoring resistance to stress corrosion cracking, in the case of the corrosion-resistant alloys.

However, the annealing of material subjected to low levels of cold-work (less than about 7 to 10% outer fiber elongation) is generally not suggested since it can result in abnormal grain growth, leading to a surface condition known as “orange peel” or “alligator hide”, and significantly affect properties.  Please refer to any additional ‘Fabrication and Welding’ information for the specific alloy or contact Haynes International for further guidance.

As discussed below, it is very important that any lubricants, or other foreign matter, be carefully removed from the surfaces of the workpiece prior to any intermediate (or final) annealing treatment, to prevent the diffusion of detrimental elements into the alloy.

It is highly recommended that any scales (i.e. surface films) caused by intermediate annealing treatments be removed prior to the next forming operation by pickling or mechanical means.

Lubrication is a significant consideration for successfully cold-working the HAYNES® and HASTELLOY® alloys. Although lubrication is not normally required for simple bending operations, the use of lubricants may be essential for other forming operations, such as cold-drawing. Mild forming operations can be successfully completed using lard oil or castor oil, which are easily removed. More severe forming operations require metallic soaps or chlorinated/sulfo-chlorinated oils. When sulfo-chlorinated oils are used, the work-piece must be carefully cleaned in a de-greaser or alkaline cleaner, after each step (to prevent sulfur diffusion into the alloy during subsequent annealing).

Lubricants that contain white lead, zinc compounds, or molybdenum disulfide are not recommended because they are difficult to remove and can cause lead, zinc, or sulfur to diffuse into the alloy during subsequent annealing, resulting in severe embrittlement. For the same reason, any die materials, lubricants, or foreign matter should be carefully removed from the work-piece before any intermediate or final annealing treatments.

Bending, Roll-Forming, Roll-Bending, and Press-Braking

Recommended Procedures Applicable to:

HAYNES® and HASTELLOY® sheets and plates are amenable to simple bending, roll-forming, roll-bending, and press-braking operations. Lubrication is not generally required for such operations. Minimum bend radius guidelines are given in the table below, but may vary from alloy to alloy.

Material Thickness Suggested Minimum Bend Radius*
in mm -
<0.050 <1.27 1T
0.050-0.187 1.27-4.75 1.5T
0.188-0.500 4.76-12.70 2T
0.501-0.750 12.71-19.05 3T
0.751-1.000 19.06-25.40 4T

*T = Material thickness

Thick sections may require multiple steps, with intermediate annealing treatments to restore ductility. These treatments should be performed in accordance with the recommendations given in the Heat Treatment section, and again care must be taken to clean the surfaces of the work-piece prior to annealing.

Deep Drawing, Stretch Forming, and Hydroforming

Recommended Procedures Applicable to:

The HAYNES® and HASTELLOY® alloys are amenable to deep drawing, stretch forming, hydro-forming, and such like. Lubrication is generally required for these processes. In the case of the high temperature alloys, fine-grained starting material possessing superior forming characteristics may be available. As with bending operations, thick sections may require multiple steps, with intermediate annealing treatments to restore ductility. These treatments should be performed in accordance with the recommendations given in the Heat Treatment section, and again care must be taken to clean the surfaces of the work-piece prior to annealing.

As a guide to the formability of the high-temperature alloys, Olsen Cup (lubricated) test results are provided below for some of the alloys, along with 310 stainless steel for comparison.

Alloy Average Olsen Cup Depth*
- in mm
25 0.443 11.3
188 0.490 12.4
230® 0.460 11.7
556® 0.480 12.2
625 0.440 11.2
S 0.513 13.0
X 0.484 12.3
310 Stainless Steel 0.505 12.8

*Average of 3 to 12 measurements on 0.040-0.070 in (1.0-1.75 mm) thick sheet

Spinning and Shear Spinning

Recommended Procedures Applicable to:

Spinning is a deformation process for forming sheet metal or tubing into seamless hollow cylinders, cone hemispheres, or other symmetrical circular shapes, by a combination of rotation and force. There are two basic forms, known as manual spinning and power (or shear) spinning. In the former method, no appreciable thinning of the metal occurs, whereas in the latter, metal is thinned as a result of shear forces.

Nearly all HAYNES® and HASTELLOY® alloys can be spin formed, generally at room temperature. The control of quality, including freedom from wrinkles and scratches, in addition to dimensional accuracy, is largely dependent upon operator skill. The primary parameters that should be considered when spinning these alloys are:

  • Speed
  • Feed Rate
  • Lubrication
  • Material
  • Strain Hardening Characteristics
  • Tool Material, Design, and Surface Finish
  • Power of the Machine

Optimum combinations of speed, feed, and pressure are normally determined experimentally when a “new job” is set up. During continuous operation, changes in the temperature of the mandrel and spinning tool may necessitate the adjustment of pressure, speed, and feed to obtain uniform results.

Lubrication should be used in all spinning operations. The usual practice is to apply lubricant to the blank prior to loading of the machine. It may be necessary to add lubricants during operation. During spinning, the work-piece and tools should be flooded with a coolant, such as an emulsion of soluble oil in water.

Sulfurized or chlorinated lubricants should not be used, since the spinning operation might burnish the lubricant into the surface, resulting in detrimental surface effects (due to diffusion of sulfur and/or chlorine) during any subsequent annealing treatments. If these types of lubricant are used accidentally, they should be thoroughly removed (by grinding, polishing, or pickling) prior to any intermediate or final anneal.

The tool material, work-piece design, and surface finish are all very important in achieving trouble-free operation. Mandrels used in spinning must be hard, wear-resistant, and resistant to the fatigue resulting from normal eccentric loading.

As is the case for other cold-forming operations, parts produced by cold spinning should be intermediate and final annealed in accordance with the recommendations in the Heat-Treatment section of this guide.

Tube-forming

Recommended Procedures Applicable to:

The HAYNES® and HASTELLOY® alloys can be cold formed in standard pipe and tube bending equipment. The minimum recommended bending radius, from the radius point to the centerline of the tube, is three times the tube diameter, for most bending operations. When measured from centerline to centerline of the “hairpin” straight legs, it is six times the tube diameter. On the other hand, there are some combinations of tube diameter and wall thickness where a bending radius of twice the tube diameter is possible (from the radius point to the centerline of the tube).

As the ratio of tube diameter to wall thickness increases, the need for internal and external support becomes increasingly important, in order to prevent distortion. If too small a bending radius is used, then wrinkles, poor ovality, and buckling can occur (in addition to wall thinning).

Punching

Recommended Procedures Applicable to:

Punching of the HAYNES® and HASTELLOY® alloys is usually performed at room temperature. Perforation should be limited to a minimum diameter of twice the gage thickness. The center-to-center dimension should be approximately three to four times the diameter of the hole.

Punch to Die Clearances per Side
Annealed Sheet up to 0.125 in (3.2 mm) 3-5% of Thickness
Annealed Sheet or Plate over 0.125 in (3.2 mm) 5-10% of Thickness

Cutting and Shearing

Recommended Procedures Applicable to:

In view of the high strengths and high work-hardening rates of the HAYNES® and HASTELLOY® alloys (relative to many austenitic stainless steels), band saw cutting is generally ineffective. For flat products, shearing can be successful on “scissor-type” shears rated for carbon steel thicknesses at least 50% above the alloy thickness involved.

Generally, alloy thicknesses up to 0.4375 in (11.1 mm) are shear-able, while thicker material is normally cut by abrasive saw or plasma arc. Abrasive water-jet cutting is not normally recommended, but may be practical in some cases. Bar and tubular products are normally cut using abrasive saws.

Resin-bonded, aluminum oxide wheels are used to successfully cut the HAYNES® and HASTELLOY® alloys. A typical grain and grade designation is 86A361-LB25W EXC-E.

The HAYNES® and HASTELLOY® alloys can be plasma arc cut using any conventional system. The best arc quality is achieved using a mixture of argon and hydrogen gases. Nitrogen gas can be substituted for hydrogen; however, this will result in a cut of reduced quality. Shop air and oxygen-containing gases are unsuitable and should be avoided when plasma cutting these alloys.

Oxy-acetylene cutting of these alloys is not recommended. Air carbon arc cutting is feasible, but subsequent grinding, to remove any carbon contamination, is likely to be required.

Heat Treatment

Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy

The heat treatment of the HAYNES® and HASTELLOY® alloys is a very important topic. In the production of these wrought materials, there are many hot- and cold-reduction steps, between which intermediate heat treatments are necessary, to restore the optimum properties, in particular ductility. In the case of the corrosion-resistant alloys, these intermediate heat treatments are generally solution-annealing treatments. In the case of the high-temperature alloys, this is not necessarily so.

Once the materials have reached their final sizes, they are given a final anneal. This is usually a solution-anneal; however, a few high-temperature alloys (HTA) are final annealed at an adjusted temperature, to control grain size, or some other microstructural feature.

Subsequent fabrication of these as-supplied materials can again involve hot- or cold-working, as discussed in the Hot-working and Cold-working sections of this guide. Again, working often involves steps, with intermediate annealing (normally solution-annealing for the CRA materials) treatments to restore ductility. Beyond that, fabricated components will require a final anneal (normally a solution-anneal for the CRA materials), to restore optimum properties prior to use, or (in the case of the age-hardenable alloys) to prepare them for age-hardening.

Applicable to:
Corrosion-resistant Alloys

The compositions of the corrosion-resistant alloys (CRA) comprise a nickel base, substantial additions of chromium and/or molybdenum (in some cases partially replaced by tungsten), small additions such as copper (to enhance resistance to certain media) and iron (to allow the use of less expensive raw materials), and minor additions such as aluminum and manganese, which help remove deleterious elements such as oxygen and sulfur, during melting. As-supplied, they generally exhibit single phase (face-centered cubic, or gamma) wrought microstructures.

In most cases, the presence of a single phase microstructure in as-supplied (CRA) materials is due to a high temperature, solution-annealing treatment, followed by quenching (rapid cooling), to “lock-in” the high-temperature structure. Left to cool slowly, most of these alloys would contain second phases (albeit in small amounts), commonly within the structural grain boundaries, as a result of the fact that the combined contents of the alloying additions exceed their solubility limits.

This is exacerbated by the fact that, despite sophisticated melting techniques and procedures, traces of unwanted elements (with very low solubility), such as carbon and silicon, can be present. Fortunately, solution-annealing, followed by quenching (by water or cold gas), solves this problem also.

The corrosion-resistant alloys are usually supplied in the solution-annealed condition, and their normal solution-annealing temperatures are given in the table below. They represent temperatures at which phases other than gamma (and, in rare cases, primary carbides and/or nitrides) dissolve, yet provide grain sizes within the range known to impart good mechanical properties. Primary carbides and/or nitrides are seen in C-4 alloy, due to the presence of titanium.

In the case of the corrosion-resistant alloys (CRA), the terms solution-annealed and mill-annealed (MA) are generally synonymous; however, the temperatures used in continuous hydrogen-annealing furnaces (in sheet production) are adjusted to compensate for the line speeds (hence time at temperature).

Solution-annealing Temperatures of the Corrosion-resistant Alloys (CRA)

Alloy Solution-annealing Temperature* Type of Quench
- °F °C -
B-3® 1950 1066 WQ or RAC
C-4 1950 1066 WQ or RAC
C-22® 2050 1121 WQ or RAC
C-22HS® 1975 1079 WQ or RAC
C-276 2050 1121 WQ or RAC
C-2000® 2100 1149 WQ or RAC
G-30® 2150 1177 WQ or RAC
G-35® 2050 1121 WQ or RAC
HYBRID-BC1® 2100 1149 WQ or RAC

*Plus or Minus 25°F (14°C)
WQ = Water Quench (Preferred); RAC = Rapid Air Cool

There are no specific rules regarding the times required to heat up, then anneal, the corrosion-resistant alloys (CRA), since there are many types of furnace, involving different modes of loading, unloading, and operation. There are only general guidelines.

The temperature of the work-piece being annealed should be measured with an attached thermocouple, and recording of the annealing time should begin only when the entire section of the work-piece has reached the recommended annealing temperature. It should be remembered that the center of the section takes longer to reach the annealing temperature than the surface.

The general guidelines regarding time are:

  • Normally, once the whole of the workpiece is at the annealing temperature, the annealing time should be between 10 and 30 minutes, depending upon the section thickness.
  • The shorter times within this range should be used for thin sheet components.
  • The longer times should be used for thick (heavier) sections.

Rapid cooling is essential after annealing, to prevent the nucleation and growth of deleterious second phase precipitates in the microstructure, particularly at the grain boundaries. Water quenching is preferred, and highly recommended for materials thicker than 3/8 in (9.5 mm). Rapid air cooling has been used for thin sections. The time between removal from the furnace and the start of quenching must be as short as possible (and certainly less than three minutes).

Special precautions are necessary with B-3® alloy. Although more stable than other nickel-molybdenum alloys (particularly its predecessor, B-2® alloy), it is still prone to significant, deleterious, microstructural changes in the temperature range 1100-1500°F (593-816°C), especially after being cold-worked. Thus, care must be taken to avoid exposing B-3® alloy to temperatures within this range for any length of time. B-3®alloy should be annealed in furnaces pre-heated to the annealing temperature (1950°F/1066°C), and with sufficient thermal capacity to ensure rapid recovery of the temperature after loading of the furnace with the B-3® work-piece.

One of the potential problems associated with these microstructural changes (which can occur during heating to the annealing temperature) in the nickel-molybdenum (B-type) alloys is cracking due to residual stresses, in cold-worked material. Shot peening of the knuckle radius and straight flange regions of cold-formed heads, to lower residual tensile stress patterns, has been found to be very beneficial in avoidance of such problems. Cold or hot formed heads should always be annealed after forming, regardless of forming strain level. This is especially important if the material is to be subsequently welded.

Applicable To:
High-temperature Alloys

The high-temperature alloys (HTA), whether based on nickel, cobalt, or a mixture of nickel, cobalt, and iron, are compositionally much more complicated. However, as in the CRA alloys, chromium is an important alloying element, enabling the formation of protective, surface films (particularly oxides) in hot gases.

Large atoms such as molybdenum and tungsten are used to provide solid-solution strength to many of the high-temperature alloys. Those relying on age-hardening for strength include significant quantities of elements such as aluminum, titanium, and niobium (columbium), which can form extremely fine precipitates of second phases (“gamma prime” and “gamma double prime”) known to be very effective strengtheners.

Aluminum can play another role in the high temperature alloys, and that is to modify the protective films (oxides, in particular) that form on the surfaces of these materials at high-temperatures, in the presence of oxygen, etc. Indeed, aluminum oxide is very adherent, stable, and protective.

Unlike the CRA materials, in which carbon is generally a negative actor, the high-temperature HAYNES® and HASTELLOY® (HTA) alloys rely upon deliberate carbon additions, or rather the carbides they induce in the microstructures, to provide the necessary levels of strength (particularly creep strength) for high-temperature service. In some cases, these carbides form during solidification of the materials (primary carbides). In other cases, they form during high-temperature exposure, in the solid state (secondary carbides).

As a consequence of the need for specific carbide types and morphologies in the HTA materials, annealing is a much more complicated subject, especially between steps in the manufacturing and fabrication processes.

The high-temperature HAYNES® and HASTELLOY® alloys are normally supplied in the solution-annealed condition, which is attained by heat treatment at the following temperatures (or within the specified ranges):

Solution-annealing Temperatures of the High-temperature Alloys (HTA)

Alloy Solution-annealing Temperature/Range Type of Quench
- °F °C -
25 2150-2250 1177-1232 WQ or RAC
75 1925* 1052* WQ or RAC
188 2125-2175 1163-1191 WQ or RAC
214® 2000 1093 WQ or RAC
230® 2125-2275 1163-1246 WQ or RAC
242® 1900-2050 1038-1121 WQ or RAC
244® 2000-2100 1093-1149 WQ or RAC
263 2100 + 25 1149 + 14 WQ or RAC
282® 2050-2100 1121-1149 WQ or RAC
556® 2125-2175 1163-1191 WQ or RAC
625 2000-2200 1093-1204 WQ or RAC
718 1700-1850** 927-1010** WQ or RAC
HR-120® 2150-2250 1177-1232 WQ or RAC
HR-160® 2025-2075 1107-1135 WQ or RAC
HR-224®     WQ or RAC
HR-235® 2075-2125 1135-1163 WQ or RAC
MULTIMET® 2150 1177 WQ or RAC
N 2150 1177 WQ or RAC
R-41 2050 1121 WQ or RAC
S 1925-2075 1052-1135 WQ or RAC
W 2165 1185 WQ or RAC
WASPALOY 1975 1079 WQ or RAC
X 2125-2175 1163-1191 WQ or RAC
X-750 1900* 1038* WQ or RAC

WQ = Water Quench (Preferred); RAC = Rapid Air Cool
*Bright (Hydrogen) Annealing Temperature
**Not Strictly a Solution-annealing Temperature Range (More a Preparatory Annealing Temperature Range)

In the solution-annealed condition, the microstructures of the high-temperature alloys (HTA) generally consist of primary carbides dispersed in a gamma phase (face-centered cubic) matrix, with essentially clean (precipitate-free) grain boundaries. For the solid-solution strengthened alloys, this is usually the optimum condition for both high-temperature service, and for room temperature fabricability.

Although the HAYNES® and HASTELLOY® alloys should not be subjected to stress relief treatments at the sort of temperatures used for the steels and stainless steels, for fear of causing the precipitation of undesirable second phases (particularly in the alloy grain boundaries), some lower annealing temperatures have been used for the high-temperature alloys (HTA) between processing steps, to restore the ductility of partially-fabricated workpieces. These so-called intermediate annealing temperatures should be used with caution, since they too are likely to result in the aforementioned grain boundary precipitation. Some minimum, intermediate annealing temperatures are given in the following table (for selected solid-solution strengthened HTA materials):

Minimum Intermediate Annealing Temperatures (HTA)

Alloy Minimum Intermediate Annealing Temperature
- °F °C
25 2050 1121
188 2050 1121
230® 2050 1121
556® 1900 1038
625 1700 927
HR-120® 1950 1066
HR-160® 1950 1066
S 1750 954
X 1850 1010

Whether an intermediate annealing temperature (rather than a solution-annealing temperature) is appropriate between processing steps will depend upon the alloy and the effects of the lower temperature upon microstructure, and upon the nature of the subsequent operation. These issues must be studied carefully, and advice sought.

Annealing During Cold (or Warm) Forming

Applicable To:
High-temperature Alloys

The response of the HAYNES® and HASTELLOY® high-temperature alloys (HTA) to heat treatment is very dependent upon the condition of the material prior to the treatment. When the material is not in a cold- or warm-worked condition, the principal response is usually a change in the amount and morphology of the secondary carbide phases. Other minor effects might occur, but the grain structure normally remains the same (in the absence of prior cold or warm work).

When these alloys have been subjected to cold- or warm-work, the application of a solution or intermediate anneal will almost always alter the grain structure. Moreover, the amount of prior cold- or warm-work will significantly affect the grain structure, and consequently the mechanical properties of the material.

The following table indicates the effects of heat-treatments (of 5 minutes duration) at various temperatures upon the grain sizes of sheets of several high temperature alloys, subjected to different levels of cold-work.

Effects of Cold-work and Heat Treatment Temperature on Grain Size

Cold-work Heat TreatmentTemperature Cold-work
% °F °C 25 230® 556® X
0 None 3.5-4 3.5-4 3.5-4 3.5-4
10 1850 3.5-4 3.5-4 3.5-4 NR 3.5-4
1950 3.5-4 3.5-4 3.5-4 NR 3.5-4
2050 3.5-4 3.5-4 3.5-4 5-5.5 3.5-4
2150 3.5-4 3.5-4 3.5-4 5-5.5 3.5-4
2250 3.5-4 3.5-4 3.5-4 NA 3.5-4
15 1950 3.5-4 3.5-4 3.5-4 NA 3.5-4
2050 3.5-4 3.5-4 3.5-4 NA 3.5-4
2150 3.5-4 3.5-4 3.5-4 NA 3.5-4
2250 3.5-4 3.5-4 3.5-4 NA 3.5-4
20 1850 3.5-4 3.5-4 3.5-4 NR 3.5-4
1950 3.5-4 3.5-4 3.5-4 NR 3.5-4
2050 3.5-4 3.5-4 3.5-4 7.5-8.5 3.5-4
2150 3.5-4 3.5-4 3.5-4 6-6.5 3.5-4
2250 3.5-4 3.5-4 3.5-4 NA 3.5-4
25 1950 3.5-4 3.5-4 3.5-4 NA 3.5-4
2050 3.5-4 3.5-4 3.5-4 NA 3.5-4
2150 3.5-4 3.5-4 3.5-4 NA 3.5-4
2250 3.5-4 3.5-4 3.5-4 NA 3.5-4
30 1850 3.5-4 3.5-4 3.5-4 NFR 3.5-4
1950 3.5-4 3.5-4 3.5-4 7.5-9.5 3.5-4
2050 3.5-4 3.5-4 3.5-4 7-7.5 3.5-4
2150 3.5-4 3.5-4 3.5-4 4.5-6.5 3.5-4
2250 3.5-4 3.5-4 3.5-4 NA 3.5-4
40 1850 3.5-4 3.5-4 3.5-4 7.5-9.5 3.5-4
1950 3.5-4 3.5-4 3.5-4 8-9.5 3.5-4
2050 3.5-4 3.5-4 3.5-4 7-9 3.5-4
2150 3.5-4 3.5-4 3.5-4 4.5-6.5 3.5-4
2250 3.5-4 3.5-4 3.5-4 NA 3.5-4
50 1850 3.5-4 3.5-4 3.5-4 9-10 3.5-4
1950 3.5-4 3.5-4 3.5-4 8.5-10 3.5-4
2050 3.5-4 3.5-4 3.5-4 8-9.5 3.5-4
2150 3.5-4 3.5-4 3.5-4 5.5-6 3.5-4
2250 3.5-4 3.5-4 3.5-4 NA 3.5-4

NA=Not Available
NR= No Recrystallization Observed
NFR=Not Fully Recrystallized

The effects of cold-work plus heat treatment at various temperatures upon the mechanical properties of several solid solution strengthened, high temperature HAYNES® and HASTELLOY® alloys are shown in the following tables and figures.

Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES® 25 Sheet

Cold-work Heat Treatment* Temperature 0.2% Offset Yield Strength Ultimate Tensile Strength Elongation Hardness
% °F °C ksi MPa ksi MPa % HRC
No Cold-work No Heat Treatment 68 469 144 993 58 24
10 No Heat Treatment 124 855 182 1255 37 36
15 No Heat Treatment 149 1027 178 1227 28 40
20 No Heat Treatment 151 1041 193 1331 18 42
25 No Heat Treatment 184 1269 232 1600 15 44
10 1950 1066 98 676 163 1124 39 32
15 1950 1066 91 627 167 1151 44 30
20 1950 1066 96 662 171 1179 41 32
25 1950 1066 89 614 169 1165 44 32
10 2050 1121 74 510 157 1082 53 27
15 2050 1121 79 545 161 1110 52 28
20 2050 1121 82 565 165 1138 48 31
25 2050 1121 83 572 166 1145 48 30
10 2150 1177 67 462 148 1020 63 21
15 2150 1177 74 510 156 1076 55 26
20 2150 1177 72 496 154 1062 59 26
25 2150 1177 69 476 149 1027 62 25
10 2250 1232 69 476 144 993 64 95
15 2250 1232 64 441 142 979 68 97
20 2250 1232 62 427 135 931 69 97
25 2250 1232 61 421 138 951 70 96

*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRC= Hardness Rockwell “C”

Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES® 188 Sheet

Cold-work Heat Treatment* Temperature 0.2% Offset Yield Strength Ultimate Tensile Strength Elongation Hardness
% °F °C ksi MPa ksi MPa % HR BW/C
No Cold-work No Heat Treatment 67 462 137 945 54 98 HRBW
10 No Heat Treatment 106 731 151 1041 45 32 HRC
20 No Heat Treatment 133 917 166 1145 28 37 HRC
30 No Heat Treatment 167 1151 195 1344 13 41 HRC
40 No Heat Treatment 177 1220 215 1482 10 44 HRC
10 1950 1066 91 627 149 1027 41 30 HRC
20 1950 1066 88 607 153 1055 41 28 HRC
30 1950 1066 84 579 158 1089 41 30 HRC
40 1950 1066 91 627 163 1124 40 31 HRC
10 2050 1121 65 448 143 986 50 22 HRC
20 2050 1121 71 490 149 1027 47 25 HRC
30 2050 1121 80 552 155 1069 44 28 HRC
40 2050 1121 87 600 159 1096 43 30 HRC
10 2150 1177 62 427 140 965 55 96 HRBW
20 2150 1177 65 448 141 972 53 97 HRBW
30 2150 1177 67 462 143 986 52 99 HRBW
40 2150 1177 64 441 141 972 56 97 HRBW
10 2250 1232 59 407 132 910 59 95 HRBW
20 2250 1232 58 400 130 896 63 94 HRBW
30 2250 1232 58 400 131 903 63 93 HRBW
40 2250 1232 58 >400 132 910 62 93 HRBW

*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardness Rockwell “C”

Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES® 230® Sheet

Cold-work Heat Treatment* Temperature 0.2% OffsetYield Strength Ultimate Tensile Strength Elongation Hardness
% °F °C ksi MPa ksi MPa % HR BW/C
No Cold-work No Heat Treatment 62 427 128 883 47 95 HRBW
10 No Heat Treatment 104 717 145 1000 32 28 HRC
20 No Heat Treatment 133 917 164 1131 17 35 HRC
30 No Heat Treatment 160 1103 188 1296 10 39 HRC
40 No Heat Treatment 172 1186 202 1393 8 40 HRC
50 No Heat Treatment 185 1276 215 1482 6 42 HRC
10 1950 1066 92 634 144 993 33 24 HRC
20 1950 1066 81 558 142 979 36 26 HRC
30 1950 1066 76 524 142 979 36 99 HRBW
40 1950 1066 81 558 146 1007 32 23 HRC
50 1950 1066 86 593 148 1020 35 24 HRC
10 2050 1121 81 558 139 958 37 98 HRBW
20 2050 1121 65 448 136 938 39 97 HRBW
30 2050 1121 72 496 140 965 38 99 HRBW
40 2050 1121 76 524 142 979 36 99 HRBW
50 2050 1121 81 558 144 993 36 23 HRC
10 2150 1177 56 386 130 896 44 92 HRBW
20 2150 1177 64 441 134 924 40 96 HRBW
30 2150 1177 70 483 138 951 39 98 HRBW
40 2150 1177 73 503 139 958 38 98 HRBW
50 2150 1177 72 496 138 951 39 98 HRBW
10 2250 1232 52 359 125 862 47 92 HRBW
20 2250 1232 57 393 128 883 45 92 HRBW
30 2250 1232 54 372 126 869 48 92 HRBW
40 2250 1232 53 365 126 869 47 91 HRBW
50 2250 1232 55 379 128 883 46 89 HRBW

*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardness Rockwell “C”

Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES® 625 Sheet

Cold-work Heat Treatment* Temperature 0.2% Offset Yield Strength Ultimate Tensile Strength Elongation Hardness
% °F °C ksi MPa ksi MPa % HR BW/C
No Cold-work No Heat Treatment 70 483 133 917 46 97 HRBW
10 No Heat Treatment 113 779 151 1041 30 32 HRC
20 No Heat Treatment 140 965 169 1165 16 37 HRC
30 No Heat Treatment 162 1117 191 1317 11 40 HRC
40 No Heat Treatment 178 1227 209 1441 8 42 HRC
50 No Heat Treatment 184 1269 223 1538 5 45 HRC
10 1850 1010 63 434 134 924 46 NA
20 1850 1010 71 490 138 951 44 NA
30 1850 1010 78 538 141 972 44 NA
40 1850 1010 82 565 141 972 42 NA
50 1850 1010 82 565 141 972 42 NA
10 1950 1066 61 421 133 917 46 NA
20 1950 1066 71 490 137 945 45 NA
30 1950 1066 77 531 140 965 44 NA
40 1950 1066 83 572 142 979 42 NA
50 1950 1066 82 565 141 972 42 NA
10 2050 1121 58 400 128 883 50 NA
20 2050 1121 67 462 135 931 46 NA
30 2050 1121 58 400 127 876 52 NA
40 2050 1121 72 496 137 945 44 NA
50 2050 1121 61 421 130 896 50 NA
10 2150 1177 52 359 122 841 55 NA
20 2150 1177 54 372 124 855 55 NA
30 2150 1177 53 365 122 841 56 NA
40 2150 1177 52 359 122 841 55 NA
50 2150 1177 51 352 119 820 58 NA

*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
NA=Not Available
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardess Rockwell “C”

Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES HR-120® Sheet

Cold-work Heat-treatment* Temperature 0.2% Offset Yield Strength Ultimate Tensile Strength Elongation Hardness
% °F °C ksi MPa ksi MPa % HR BW/C
No Cold-work No Heat Treatment 60 414 113 779 39 93 HRBW
10 No Heat Treatment 103 710 126 869 26 27 HRC
20 No Heat Treatment 129 889 144 993 11 32 HRC
30 No Heat Treatment 143 986 157 1082 6 34 HRC
40 No Heat Treatment 159 1096 179 1234 6 35 HRC
50 No Heat Treatment 166 1145 186 1282 5 36 HRC
10 1950 1066 52 359 109 752 38 89 HRBW
20 1950 1066 55 379 111 765 38 92 HRBW
30 1950 1066 60 414 115 793 38 93 HRBW
40 1950 1066 65 448 117 807 37 93 HRBW
50 1950 1066 67 462 118 814 34 93 HRBW
10 2050 1121 49 338 108 745 47 88 HRBW
20 2050 1121 53 365 117 807 41 90 HRBW
30 2050 1121 55 379 112 772 40 91 HRBW
40 2050 1121 58 400 114 786 37 91 HRBW
50 2050 1121 59 407 114 786 37 89 HRBW
10 2150 1177 49 338 109 752 43 86 HRBW
20 2150 1177 50 345 109 752 42 87 HRBW
30 2150 1177 51 352 110 758 43 88 HRBW
40 2150 1177 50 345 111 765 38 86 HRBW
50 2150 1177 50 345 110 758 39 82 HRBW
10 2250 1232 46 317 106 731 46 84 HRBW
20 2250 1232 44 303 104 717 47 80 HRBW
30 2250 1232 44 303 103 710 48 80 HRBW
40 2250 1232 44 303 104 717 45 81 HRBW
50 2250 1232 44 303 104 717 43 83 HRBW

*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardness Rockwell “C”

Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HASTELLOY® X Sheet

Cold-work Heat Treatment* Temperature 0.2% Offset Yield Strength Ultimate Tensile Strength Elongation Hardness
% °F °C ksi MPa ksi MPa % HR BW/C
No Cold-work No Heat Treatment 57 393 114 786 46 89 HRBW
10 No Heat Treatment 96 662 129 889 29 25 HRC
20 No Heat Treatment 122 841 147 1014 15 31 HRC
30 No Heat Treatment 142 979 169 1165 10 35 HRC
40 No Heat Treatment 159 1096 186 1282 8 37 HRC
50 No Heat Treatment 171 1179 200 1379 7 39 HRC
10 1850 1010 76 524 125 862 32 98 HRBW
20 1850 1010 91 627 132 910 27 23 HRC
30 1850 1010 87 600 135 931 28 99 HRBW
40 1850 1010 77 531 133 917 32 98 HRBW
50 1850 1010 81 558 135 931 33 99 HRBW
10 1950 1066 74 510 122 841 34 93 HRBW
20 1950 1066 66 455 124 855 35 96 HRBW
30 1950 1066 63 434 126 869 36 96 HRBW
40 1950 1066 70 483 129 889 35 96 HRBW
50 1950 1066 74 510 129 889 34 97 HRBW
10 2050 1121 53 365 119 820 42 89 HRBW
20 2050 1121 56 386 121 834 40 91 HRBW
30 2050 1121 61 421 123 848 39 94 HRBW
40 2050 1121 65 448 125 862 37 94 HRBW
50 2050 1121 67 462 125 862 38 94 HRBW
10 2150 1177 45 310 109 752 49 94 HRBW
20 2150 1177 47 324 111 765 47 87 HRBW
30 2150 1177 49 338 113 779 46 86 HRBW
40 2150 1177 46 317 110 758 48 85 HRBW
50 2150 1177 46 317