Type Analysis | Description | Application | Corrosion Resistance
Physical Properties | Heat Treatment | Workability | Typical Mechanical Properties

Type Analysis

Description

Rene 41 is a precipitation hardening, nickel-based high temperature alloy possessing high strength in the 1200/1800°F (649/982°C) temperature range. This alloy is designed for use in severely stressed high temperature applications.

Applications

Rene 41 has found applications in jet engine and high speed airframe components such as: afterburner parts, turbine casings, wheels, buckets, bolts, and fasteners.

Corrosion Resistance

Rene 41 is highly corrosion and oxidation resistant. It provides very good resistance to jet engine combustion gases up to 1800°F (982°C).

Physical Properties

Density                                                                                         Melting range
   lb/cu in ............................... 0.298                                       °F ...................................... 2400/2500
   kg/cu m ............................... 8249                                       °C ...................................... 1316/1371

Modulus of Elasticity

Electrical resistivity

Specific heat
   Btu/lb-°F (70/600°F)...................... 0.108
   kJ/kg-K (21/316°C)........................ 0.452

Mean coefficient of thermal expansion

Thermal conductivity

Heat Treatment

Annealing
Lowest hardness is obtained by quenching from temperatures above the gamma prime solvus temperature - 1950°F (1066°C) is usually satisfactory. Hardness will be in the Rockwell B 98/C 30 range, depending on the rapidity of the quench. It is unlikely that large sections can be quenched rapidly enough to obtain low hardness.

Solution Temperatures

Gamma prime
   solvus temp............................. 1960/1980°F
                                                  (1071/1082°C)
M6C carbide......................... 2100°F (1149°C)
                                                         and higher
M23C6 carbide......................... 1800°F (982°C)
                                                         and higher

Grain growth will be encountered at temperatures above gamma prime solvus temperatures. If fine grain size and best tensile ductility are desired, the solution treatment should be executed in the range of 1900/1925°F (1038/1052°C), hold 4 hrs at temperature, then air cool.
Stress rupture properties may be improved if a temperature "above solvus" is employed - 1975°F (1080°C), hold 1 hour, then air cool.
In general, high temperature treatments should be avoided.
If the M6C carbide, normally present in this alloy, is solutioned by treating above 2100°F (1149°C), it will precipitate during cooling or aging as M23C6,a continuous grain boundary film which results in low ductility. Resolutioning - at least 1800°F (982°C) and preferably 1900°F (1038°C) - is required to restore ductility by reforming M6C.

Precipitation Hardening Treatment
Heat to 1400°F (760°C), hold at heat for 16 hrs, then air cool. Hardness will be in the Rockwell C 40/45 range.

Workability

Hot Working/Forging
Rene 41 is best forged between an initial furnace temperature of 2100°F (1149°C) and an optical finishing temperature of 1850/1900°F (1010/1038°C).

Cold Working
Rene 41 work hardens rapidly; frequent anneals will be required. Aging after cold working can be result in strain age cracking.
Cold worked sections must be heated rapidly through the aging temperature range, 1200/1700°F (649/927°C), to the solution or annealing temperature ot prevent strain age cracking. A sizable amount of cold reduction between anneals is mandatory. Small reductions, such as sizing passes, must be avoided.

Machinability
Rene 41 is difficult to machine. Tungsten carbide tools are recommended. Suggested tool geometry, speeds and feeds are as follows:
0° back rake
6° side rake
7° clearance end and size
10° end cutting edge angle
45° side cutting edge angle
1/16" (1.59 mm) nose radius
The following parameters have been found satisfactory:
Feed - 0.005/0.011"(0.13/0.28mm)
Depth of cut - 1/32-1/8"(0.79/3.18mm)
Speeds - 30/60ft. per minute (0.15/0.30 m/s)
Machined finishes are generally better when the alloy is in the fully treated or partially aged condition. Air cooling from the solution or annealing treatment is adequate.
If the solution treating is required after finish machining, treating in a protective atmosphere to prevent intergranular surface oxidation is suggested.
Surface oxidation is minor at aging temperatures; thus, machining followed by aging may be useful for some applications.
Caution:
Aging will result in a size change (contraction) of about 0.0013 inch per inch if the stock is quenched from the prior solution treatment.
The following chars include typical machining parameters used to machine Rene 41. The data listed should be used as a guide for initial mahcine setup only.

Turning-Single Point and Box Tools

Turning-Cut Off and Form Tools

Drilling

Tapping

Reaming

Figures used for all metal removal operations covered are average. On certain work, the nature of the part may require adjustment of speeds and feeds. Each job has to be developed for best production results with opitmum tool life. Speeds and feeds should be increased or decreased in small steps.

Welding
Rene 41 can be welded by inert gas-arc methods. The part should be in the solution treated condition, 1950/1975°F (1066/1080°C) for 4 hours, and preferably water quenched.
The alloy should be re-solution treated, preferably 1900/1925°F (1038/1052°C), after welding. In addition, an aging treatment of 1650°F (899°C) for 1 hour , air cool, can be employed prior to the final 1400°F (760°C) precipitation hardening treatment to minimize the potential for cracking.

Typical Mechanical Properties

The following charts report mechanical properties from material solution treated 1950°F, 4 hrs, air cooled and aged 1400°F, 16 hrs, air cooled.

Room and Elevated Temperature Tensile Properties

Elevated Temperature Stress Rupture Properties

Rene 41 - Current Inventory Stock