www.specialmet als

1 INCOLOY alloy 925w w 21 199 38 199 93 195 149 192 204 188 260 185 316 182 371 178 427 175 482 172 168 593 164 160 155 150 145 139 132 alloy 925 (UNS N09925) is an age-hardenable nickel -iron-chromium alloy with additionsof molybdenum, copper, titanium and aluminum.

2 Thealloy s chemical composition, listed in Table 1, isdesigned to provide a combination of high strength andexcellent corrosion resistance. The nickel content issufficient for protection against chloride-ion stress-corrosion cracking. The nickel , in conjunction with themolybdenum and copper, also gives outstandingresistance to reducing chemicals. The molybdenum aidsresistance to pitting and crevice corrosion. The alloy schromium content provides resistance to oxidizingenvironments. The titanium and aluminum additionscause a strengthening reaction during heat alloy 925 is used in variousapplications requiring a combination of high strengthand corrosion resistance.

3 Because of the alloy sresistance to sulfide stress cracking and stress-corrosioncracking in sour (H2S containing) crude oil andnatural gas, it is used for down-hole and surface gas-well components including tubular products, valves,hangers, landing nipples, tool joints and packers. Thealloy is also useful for fasteners, marine and pumpshafting and high-strength piping 1 - Limiting Chemical Composition (UNSN09925) ofINCOLOY alloy 925, % nickel ..22 .. PropertiesSome physical constants of INCOLOY alloy 925 aregiven in Table 2. They are room-temperature valuesexcept for the melting range.

4 Table 3 provides physicalproperty data for INCOLOY alloy 925 at elevatedtemperatures. Coefficient of expansion and specific heatdata over a range of temperatures are in Table temperature thermophysical properties are givenin Table 2 - Physical Properties of INCOLOY alloy 925 Density, Range, Resistivity, at 200 oersteds ( kA/m) .. 3 - Elevated Temperature Dynamic Young s Modulusand Shear Modulus Values for INCOLOY alloy 925(hot rolled round, solution-annealed and aged)FPoissons RatioGPa103ksiGPa103ksiCTemperatureShear ModulusYoung sModulusINCOLOY fialloy 925223 73 212 392 572 752 932 1112 4 - Thermal Properties of INCOLOY alloy 925 TemperatureCoefficient ofExpansionaTemperatureS pecific HeatCoefficient ofExpansionaS pecific HeatF m/m CCBtu/lb F10-6 in/in FJ/kg C70.

5 - 435100 456200 486300 507400 532500 561600 586700 611800 641900 - 666aExpansion testing in accordance with ASTM E228. Reference temperature = 77 F (25 C).Table 5 - Elevated Temperature Thermophysical Properties ofINCOLOY alloy 925 (hot rolled round, solution-annealed and aged)CBTU in/ft2hFW/m CFTemperatureThermal ConductivityMechanical PropertiesMechanical properties at room temperature of solution-annealed and solution-annealed plus aged products are givenin Table 6.

6 Mechanical properties limits for specificationpurposes are shown in Table 7 (Special Metals Corporationinternal specification HA 46).As shown in Figure 1, INCOLOY alloy 925 retains asubstantial portion of its strength at temperatures up to about1200 F (650 C). Figure 2 shows rotating beam fatigue data forINCOLOY alloy 925 and MONEL alloy 3 shows mean axial stress vs. cycles of fatigue inthe 1365 F (740 C) dual aged condition. The compressiontest result, at room temperature, for a solution-annealed andaged bar was ksi (846 MPa) and the yield strengthtension test result was ksi (851 MPa)500600700800900800600400200018016014 01201008060402000 200 400 600 800 1000 1200 1400 1600100011001200100200300400 ElongationTensile StrengthY ield Strength( Offset)Temperature, FElongation, % Stress, ksiTemperature, CS tress, MPaFigure 1.

7 Tensile properties at high temperatures of solution-annealed and aged INCOLOY alloy 9253 Cold Worked5/8 965 105 724 18 25 35 26 38to to Worked1 965 110 758 18 25 35 26 38to 10 to 254 685 271 56 76 BRound/Solution-Annealed 1154 832 27 32 Cand AgedCold Drawn Tubing/Solution- 1189 830 27 35 CAnnealed and AgedTable 6 - Tensile Properties of INCOLOY alloy 925 Form/ConditionY ield Strength ( Offset)Tensile StrengthRockwellksi M P a ksi M P a %Hardness*Elongation*All values meet the requirements of NACE Standard 7 - Mechanical Property Limits for INCOLOY alloy 925, Solution-Annealed and Aged Material (SMC internal specification HA 46)ConditionHardness2 Rockwell CReduction ofAreaminimumImpactStrength1min.

8 AverageElongation in 2in ( mm) or4D ield Strength( offset) mftlbf%%MPaksiMPaksimmin1 Charpy V-Notch - Impact test s performed at -75 F (-60 C), in accordance with ASTM E23. Capability of meeting the strengths shown at room temperature is testing in accordance with ASTME to FailureS tress, ksiStress, MPaINCOLOY alloy 925 MONEL alloy K-500 Figure 2. Rotating beam fatigue data for INCOLOY alloy 925 andMONEL alloy to FailureM e a n S tress, ksiMean Stress, MPaFigure 3. Mean axial stress vs. cycles of fatigue for INCOLOY alloy925 in the 1365 F (740C) dual aged condition. 9254 MetallurgyINCOLOY alloy 925 is an austenitic nickel -iron-chromiumalloy made precipitation hardenable by additions of titaniumand aluminum.

9 The precipitation-hardening (age-hardening) heat treatment causes precipitation of gammaprime phase, Ni3(Al, Ti). The phase greatly increases boththe hardness and strength of the to elevated temperatures also causesformation of other phases, including eta and sigma. Figure 4is a time-temperature-transformation diagram, and Figure 5shows effects of the phases on impact strength of thesolution-annealed plus aged ResistanceINCOLOY alloy 925 has a high level of corrosionresistance. In both reducing and oxidizing environments, thealloy resists general corrosion, pitting, crevice corrosion,intergranular corrosion and stress-corrosion cracking.

10 Someenvironments in which INCOLOY alloy 925 is particularlyuseful are sour (H2S containing) crude oil and natural gas,sulfuric acid, phosphoric acid, and performance of INCOLOY alloy 925 underconditions representing sour gas wells is indicated in Figure6 and Tables 8, 9 and 10. Figure 6 shows resistance to stress-corrosion cracking in a sour environment at high pressureand temperature. Table 8 shows that the alloy resists sulfidestress cracking, a form of hydrogen embrittlement. The testsinvolve exposure of stressed C-ring specimens (made from aportion of tubing cross section) to a solution containinghydrogen sulfide, sodium chloride and acetic - M23C6 GammaPrimeSigmaMCExposure Time, hExposure Temperature, FExposure Temperature, CFigure 4.