HAYNES 25 (L605, Stellite 25, UNS R30605)
AMS 5759, AMS 5537, UNS R30605

Co Base, Ni 10.0, Cr 20.0, W 15.00, Mn 1.5, C 0.33, Si 0.40, Fe 3.00, S 0.030, P 0.040

High Performance Alloys stocks and produces HAYNES 25 (L605) in this grade in the following forms: Bar, wire spools, wire cuts, sheet/plate, strip, tube. Request quote on this grade.

 

Features

• Outstanding high temperature strength
• Oxidation resistant to 1800° F
• Galling resistant
• Resistant to marine environments, acids and body fluids

 

Properties

HAYNES 25 (L605) is a non-magnetic cobalt based superalloy. HAYNES 25 (L605) maintains good strength upto 2150°F. AMS 5759 requires minimum yield strength of 45,000 psi at room temperature. HAYNES 25 (L605) maintains good oxidation resistance up to 1900° F. HAYNES 25 (L605) has a unique ability to resist corrosion in very severe environments. Highly resistant to hydrochloric acid, nitric acid and wet chlorine (subject to need for exercising care in its selection at certain con¬centrations and temperatures)

Applications

• Gas turbine engine combustion chambers and afterburners
• High temperature ball bearings and bearing races
• Springs
• Heart valves

 

 

Chemistry

Tensile Data

 

Hardenability

HAYNES 25 (L605) hardness is typically 250 BHN and never higher than 275 BHN by specification. Not significantly hardenable. Does not respond to customary aging treatments, but strain aging at relatively low temperatures (700-1100° F) can improve creep and rupture strength when the alloy is in service at temperatures under 1300° F. Also, tensile and creep strength can be improved by cold working. HAYNES 25 (L605) is an austenitic alloy.

 

Performance Profile

Alloy L605 is the strongest of the formable cobalt alloys, useful for continuous service to 1800°F. Because of long and widespread use, this alloy has been the subject of many investigations to determine its properties over a wide range of conditions, thus making it an unusually well characterized material. Alloy L-605 is also known as alloy 25.

When exposed for prolonged periods at intermediate temperatures, alloy L-605 exhibits a loss of room temperature ductility in much the same fashion as other super alloys, such as X or 625.

Alloy L-605 is welded using gas tungsten arc, gas metal arc, shielded metal arc, electron beam and resistance welding. Submerged arc welding is not recommended. Use good joint fit-up, minimum restraint, low inter-pass temperature and cool rapidly from welding. For maximum ductility fabricated components should be annealed 2150-2250°F, rapid cool.

Corrosion Resistance

HAYNES 25 (L605) resistance to high temperature oxidation and carburization is good. The alloy, while not primarily intended for aqueous corrosion, is also resistant to corrosion by acids such as hydrochloric and nitric acid, as well as being resistant to wet chlorine solutions.

Density: 0.330 lbs./cubic inch

Machinability

RATING: 15% of B-1112
TYPICAL STOCK REMOVAL RATE: 25 surface feet/minute with high speed tools, 70 surface feet/minute with carbide.

COMMENTS:
All customary machining operations are easily performed. M40 series high-speed tools are customarily used. M2 alloy and carbide tools have limited application and are not recom¬mended for end milling, drilling or tapping. Sulphur chlorinated, water-based cutting fluids work successfully when machining this alloy

COLD-WORKED PROPERTIES

Cobalt Alloy L605 has excellent strength and hardness characteristics in the cold-worked condition. These high property levels are also evident at elevated temperature, making Alloy L605 quite suitable for applications such as ball bearings and bearing races. A modest additional increase in hardness and strength can be achieved through aging of the cold-worked material.

THERMAL STABILITY

When exposed for prolonged periods at intermediate temperatures, Cobalt Alloy L605 exhibits a loss of room temperature ductility in much the same fashion as some other solid-solution-strengthened super alloys, such as HASTELLOY® ALLOY X OR INCONEL® ALLOY 625. This behavior occurs as a consequence of the precipitation of deleterious phases. In the case of Alloy L605, the phase in question is CO₂W laves phase. HAYNES alloy 188 is significantly better in this regard than Alloy L605.

*Composite of multiple sheet lot tests.

 

 

 

 

METAL-TO-METAL GALLING RESISTANCE

Cobalt Alloy L605 exhibits excellent resistance to metal galling. Wear results shown below were generated for standard matching material room-temperature pin on disc tests. Wear depths are given as a function of applied load. The results indicate that Alloy L605 is superior in galling resistance to many materials, and is surpassed only by ULTIMETTM alloy and HAYNES alloy 6B. Both of these materials were specifically designed to have excellent wear resistance.

 

HIGH-TEMPERATURE HARDNESS PROPERTIES

The following are results from standard vacuum furnace hot hardness tests. Values are given in originally measured DPC (Vickers) units and conversions to Rockwell C/B scale in parentheses.

 

AQUEOUS CORROSION RESISTANCE

HAYNES 25 (L605) was not designed for resistance to corrosive aqueous media. Representative average corrosion data are given for comparison. For applications requiring corrosion resistance in aqueous environments, ULTIMET alloy and HASTELLOY® corrosion-resistant alloys should be considered.

OXIDATION RESISTANCE

Cobalt Alloy L605 exhibits good resistance to both air and combustion gas oxidizing environments, and can be used for long-term continuous exposure at temperatures up to 1800°F (980°C). For exposures of short duration, Alloy L605 can be used at higher temperatures.

Oxidation Test Parameters

Burner rig oxidation tests were conducted by exposing samples 3/8 in. x 2.5 in. x thickness (9 mm x 64 mm x thickness), in a rotating holder, to products of combustion of No. 2 fuel oil burned at a ratio of air to fuel of about 50:1. (Gas velocity was about 0.3 mach). Samples were automatically removed from the gas stream every 30 minutes and fan-cooled to near ambient temperature and then reinserted into the flame tunnel.

*Flowing air at a velocity of 7.0 ft./min. (213.4 cm/min.) past the samples. Samples cycled to room temperature once a week.
**Metal Loss + Average Internal Penetration.

 

Machining

Machinability Ratings

 

The alloys described here work harden rapidly during machining and require more power to cut than do the plain carbon steels. The metal is ‘gummy,’ with chips that tend to be stringy and tough. Machine tools should be rigid and used to no more than 75% of their rated capacity. Both work piece and tool should be held rigidly; tool overhang should be minimized. Rigidity is particularly important when machining titanium, as titanium has a much lower modulus of elasticity than either steel or nickel alloys. Slender work pieces of titanium tend to deflect under tool pressures causing chatter, tool rubbing and tolerance problems.
Make sure that tools are always sharp. Change to sharpened tools at regular intervals rather than out of necessity. Titanium chips in particular tend to gall and weld to the tool cutting edges, speeding up tool wear and failure. Remember- cutting edges, particularly throw-away inserts, are expendable. Don't trade dollars in machine time for pennies in tool cost.

Feed rate should be high enough to ensure that the tool cutting edge is getting under the previous cut thus avoiding work-hardened zones. Slow speeds are generally required with heavy cuts. Sulfur chlorinated petroleum oil lubricants are suggested for all alloys but titanium. Such lubricants may be thinned with paraffin oil for finish cuts at higher speeds. The tool should not ride on the work piece as this will work harden the material and result in early tool dulling or breakage. Use an air jet directed on the tool when dry cutting, to significantly increase tool life.

Lubricants or cutting fluids for titanium should be carefully selected. Do not use fluids containing chlorine or other halogens (fluorine, bromine or iodine), in order to avoid risk of corrosion problems. The following speeds are for single point turning operations using high speed steel tools. This information is provided as a guide to relative machinability, higher speeds are used with carbide tooling.

 

RA330 TM and RA333 TM are Registered Trademarks of Rolled Alloys
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20Cb-3 TM is a Registered Trademark of Carpenter Technology
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