L-605

Haynes Stellite® 25 (HS-25) - Alloy L-605 - UNS R30605 - F90 - Alacrite - CoNiCrW Alloy

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Table of Contents
Datasheet Chemistry
Inventory Applications
General Data Mechanical Properties
Specifications Physical Properties & Application Data
Machining, Welding, & Processing References

Alloy L605 (also known as Haynes® 25) is the strongest of the fabricable cobalt alloys and is useful for continuous service to 1800 °F. L605 also maintains good strength up to 2150 °F.

Because of its long and widespread use, this alloy has been the subject of many investigations to determine its properties over a wide range of conditions. The vast research makes this alloy an unusually well characterized material. When exposed for prolonged periods at intermediate temperatures, alloy L605 exhibits a loss of room temperature ductility in much the same fashion as other superalloys, such as alloy X or alloy 625.

L605 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 interpass temperature, and cool rapidly from welding. For maximum ductility, fabricated components should be annealed 2150-2250 °F and rapidly cooled.

L605 maintains good oxidation resistance up to 1900 °F and has a unique ability to resist corrosion in very severe environments. It is highly resistant to hydrochloric acid, nitric acid, and wet chlorine (exercise care in its selection at certain concentrations and temperatures).

Datasheet

View or download Haynes' alloy 25/L605 datasheet here

Chemistry*

Nominal Composition (Weight%)
Co 51 Bal.
Ni 10
Cr 20
W 15
Fe 3 Max.
Mo 1 Max.
Mn 1.5
Si 0.4 Max.
C 0.1
*Composition information provided by Haynes' datasheet on HS 25 (L605), available here.

Typical Inventory

Round Bar, Plate, Machined, Forge

Applications

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

General Data

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

Mechanical Properties

The typical properties listed can usually be provided in rounds, sheet, strip, plate, & custom forgings. We have the equipment to produce small quantities in special sizes to meet our customers’ specific needs. The table below shows Haynes' Nominal Mechanical/Tensile Properties of Alloy 25 (L-605) Rod & Bars. For most common forms and exceptions, check out the datasheet linked underneath the table.

Form Cond. UTS ksi (MPa) 0.2% OS YS ksi (MPa) Elong., % Rockwell Hardness
Sheet Solution Treated 144.5 (996) 69 (476) 54.7 97B
Plate Solution Treated 145.1 (1000) 68.7 (474) 58.8 99B
Bar HR & Solution Anneal 147 (1015) 73 (505) 60 98B

UTS = Ultimate Tensile Strength, YS = Yield Strength, OS = Offset, HR = Hot Rolled

Link to Haynes' datasheet/brochure on HS 25

Common Specifications

Note that the specifications listed are common for this alloy but are for reference only and may be specific to a certain form. The specifications listed are not comprehensive nor indicative of any edition, revision, or similar such as an amendment. Please, reach out to our sales department to request the Material Test Report (MTR) or to confirm your required specifications.

Form Standard
Identification UNS R30605, EN 2.4964
Bar AMS 5759
Cold Worked Bar MCS 1031
Sheet, Plate, or Strip AMS 5537
Forging AMS 5759
Weld Wire AMS 5796
Weld Electrode AMS 5797
Medical ASTM F90

Physical Properties

TYPICAL TENSILE PROPERTIES, COLD-WORKED SHEET
Cold
Red.
Test
Temp.
Ultimate
Tensile Strength
0.2% Yield
Strength
Elong.
in 2 in.
%
°F °C Ksi MPa Ksi MPa
10

70
1000
1200
1400
1600
1800

20
540
650
760
870
980

155
114
115
87
62
39

1070
785
795
600
425
270

105
78
80
67
47
27

725
540
550
460
325
185

41
48
37
8
13
15

15

70
1000
1200
1400
1600
1800

20
540
650
760
870
980

166
134
129
104
70
40

1145
925
890
715
485
275

124
107
111
86
52
30

855
740
765
595
360
205

30
29
15
5
9
5

20

70
1000
1200
1400
1800

20
540
650
760
980

183
156
137
107
41

1260
1075
945
740
285

141
133
120
96
30

970
915
825
660
205

19
18
2
3
4

Cold Red. = Cold Reduced

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 Ultimet® alloy and Stellite® alloy 6B. Both of these materials were specifically designed to have excellent wear resistance.

Room-Temperature Wear Depth For Various Applied Loads
 
3,000 lbs. (1.365 Kg) 6,000 lbs. (2.725 Kg) 9,000 lbs. (4.090 Kg)
Alloy mils µm mils µm mils µm
Alloy 6B 0.02 0.6 0.03 0.7 0.02 0.5
Ultimet Alloy 0.11 2.9 0.11 2.7 0.08 2.0
Alloy L605 0.23 5.9 0.17 4.2 0.17 4.2
Alloy 188 1.54 39.2 3.83 97.3 3.65 92.6
HR-160™ alloy 1.73 43.9 4.33 109.9 3.81 96.8
214™ alloy 2.32 59.0 3.96 100.5 5.55 141.0
556™ alloy 3.72 94.4 5.02 127.6 5.48 139.3
230™ alloy 4.44 112.7 7.71 195.8 8.48 215.5
HR-120™ alloy 6.15 156.2 7.05 179.0 10.01 254.2

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.

Vickers Diamond Pyramid Hardness (Rockwell C/B Hardness)
 
70°F (20°C) 800°F (425°C) 1000°F (540°C) 1200°F (650°C) 1400°F (760°C)
Solution Treated 251 (RC22) 171 (RB87) 160 (RB83) 150 (RB80) 134 (RB74)
15% Cold Work 348 (RC22) 254 (RC23) 234 (RC97) 218 (RC95) --
20% Cold Work 401 (RC35) 318 (RC32) 284 (RC27) 268 (RC25) --
25% Cold Work 482 (RC48) 318 (RC32) 300 (RC30) 286 (RC28) --

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's corrosion-resistant alloys should be considered.

Average Corrosion Rate, mils per year (mm per year)
 
1% HCl (Boiling) 10% H2SO4 (Boiling) 65% HNO3 (Boiling)
C-22™ alloy 3 (0.08) 12 (0.30) 134 (3.40)
Alloy L605 226 (5.74) 131 (3.33) 31 (0.79)
Type 316L 524 (13.31) 1868 (47.45) 9 (0.23)

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.

COMPARATIVE BURNER RIG OXIDATION RESISTANCE 1000-HOUR EXPOSURE AT 1800°F (980°C)
 
Metal Loss Average
Metal Affected
Maximum
Metal Affected
Alloy mils µm mils µm mils µm
230 Alloy 0.8 20 2.8 71 3.5 89
Alloy 188 1.1 28 3.5 89 4.2 107
Alloy X 2.7 69 5.6 142 6.4 153
Alloy 625 4.9 124 7.1 180 7.6 193
Alloy L605 6.2 157 8.3 211 8.7 221
Alloy 617 2.7 69 9.8 249 10.7 272
Alloy 800H 12.3 312 14.5 368 15.3 389
Type 310 Stainless Steel 13.7 348 16.2 411 16.5 419
Alloy 600 12.3 312 14.4 366 17.8 452

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.

COMPARATIVE OXIDATION RESISTANCE IN FLOWING AIR
 
1800°F (980°C) 2000°F (1095°C) 2100°F (1150°C)
Alloy mils µm mils µm mils µm
Alloy 188 0.6 15 1.3 33 8.0 203
230 Alloy 0.7 18 1.3 33 3.4 86
Alloy L605 0.7 18 10.2 259 19.2 488
Alloy 625 0.7 18 4.8 122 18.2 462
Alloy X 0.9 23 2.7 69 5.8 147
Alloy 617 1.3 33 1.8 46 3.4 86

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 superalloys, 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 CO2 W laves phase. Haynes® alloy 188 is significantly better in this regard than alloy L605.

ROOM-TEMPERATURE PROPERTIES OF SHEET AFTER THERMAL EXPOSURE*
Exposure
Temp. °F (°C)
Hours Ultimate
Tensile Strength
0.2% Yield
Strength
Elong.
%
Ksi MPa Ksi MPa
None 0 135.0 930 66.8 460 48.7
1200 (650) 500
1000
2500
123.6
140.0
130.7
850
965
900
70.3
92.3
95.1
485
635
655
39.2
24.8
12.0
1400 (760) 100 115.3 795 68.9 475 18.1
1600 (870) 100
500
1000
113.6
126.1
142.0
785
870
980
72.1
77.3
81.7
495
535
565
9.1
3.5
5.0

Machining

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.

Material Speed
Surface ft/mm
Speed
%B1112
AISI B1112 165 100
Rene 41 12 7
25 (L-605) 15 9
188 15 9
N-155 20 12
Waspaloy 20 12
718 20 12
825 20 12
X 20 12
RA333 20-25 12-15
A-286 30 18
RA330 30-45 18-27
HR-120® 30-50 18-30
Ti 6Al-4V
- solution annealed
- aged

30-40
15-45

18-30
9-27
RA 353 MA~ 40-60 25-35
20Cb-3~ 65 40
AL6xN~ 65 40
RA309 70 42
RA310 70 42
304 75 45
321 75 45
446 75 45
Greek Ascoloy Annealed 90 55
Hardened Rc35 50 30
303 100 60
416 145 88
17-4 PH
- solution treated
- aged Hi 025

75
60

45
36

References

Link to Haynes' general information on HS 25

Link to Haynes' datasheet/brochure on HS 25

Link to Ulbrich's information on alloy L605

Haynes® is a registered trademark of Haynes International.


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