Abstract
Heat treatments of magnets utilizing INCOLOY® alloy 908* as a conduit have been successfully performed in vacuum. Similar experience with large scale heat treatment in an inert gas environment such as argon is lacking. Prior studies on other nickel-iron base superalloys that are susceptible to intergranular oxygen embrittlement and cracking emphasize the importance of establishing an allowable oxygen impurity level in argon for alloy 908. Initial screening using C-ring tests have shown that cracking can occur in an argon atmosphere if proper control over the oxygen impurity level is not maintained. Stress-rupture tests performed in air show that this material is susceptible to intergranular cracking in notched sections when subjected to stresses in excess of 300 MPa for a stress-concentration factor (Kt) of 4.1 at the notch. A series of stress-rupture tests are now underway on alloy 908 base metal in oxygen containing argon atmospheres. A double-edged notched test specimen design is used to determine the rupture time as functions of applied stress, temperature and oxygen concentration. The oxygen concentration at the specimen notches is continuously measured using an electrochemical sensor. Initial results suggest that an argon atmosphere does yield an improved stress-rupture life over air at low oxygen concentrations. Results are discussed to establish whether the possibility for heat treatments in argon exists and if so what guidelines must be used for successful heat treatment.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
R.H. Bricknell and D.A. Woodford, “Environmental Effects in the Iron Base Alloy IN903A”, General Electric Company, Schenectady, NY, Report Number 80CRD268, (1980).
D.F. Smith, E.F. Clustworthy, D.G. Tipton, and W.L. Mankins, Improving the notch-rupture strength of low-expansion superalloys, in: “Superalloys 1980”, 521, ASM, Metals Park, OH (1980).
D.A. Woodford and R.H. Bricknell, Environmental embrittlement of high temperature alloys by oxygen, in: “Treatise on Materials Science and Technology”, C.L. Briant and S.K. Banerji, eds., Academic Press, NY, (1983)
R.H. Bricknell and D.A. Woodford, Grain boundary embrittlement of the iron-base superalloy IN903A, Met. Trans., 12A: 1673 (1981).
M.M. Morra, R.G. Ballinger, J.L. Martin, M.O. Hoenig, and M.M. Steeves, Incoloy® 9XA, a new low coefficient of thermal expansion sheathing alloy for use in ICCS magnets, in: “Advances in Cryogenic Engineering Materials”, A.F. Clark and R.P. Reed, eds., 34/157 (1987).
M.M. Morra, “Alloy 908, A New High Strength, Low Coefficient of Thermal Expansion Alloy for Cryogenic Applications”, S.M. Thesis, Massachusetts Institute of Technology, February, (1989).
M.M. Mona, R.G. Ballinger, and I.S. Hwang, Incoloy 908, a low coefficient of expansion alloy for high strength cryogenic applications: part 1-physical metallurgy, Met.Trans. A, 3177 (December 1992).
M.M. Steeves, T.A. Painter, M. Takayasu, R.N. Randall, J.E. Tracey, I.S. Hwang, and M.O. Hoenig, The US demonstration poloidal coil, IEEE Trans. Mag., 27, No. 2: 2369 (March 1991).
M.M. Steeves, M.O. Hoenig, M. Takayasu, R.N. Randall, J.E. Tracey, J.R. Hale, M.M. Mona, I. Hwang and P. Marti, Progress in the manufacture of the US-DPC test coil, IEEE Trans. Mag., 25, No. 2: 1738 (March 1989).
M.M. Steeves, T.A. Painter, J.E. Tracey, M.O. Hoenig, M. Takayasu, R.N. Randall, M.M. Mona, I.S. Hwang and P. Marti, Further progress in the manufacture of the US-DPC test coil, in: “Proceedings, 11th International Conference on magnet Technology”, Tsukuba, Japan, (1989).
S. Floreen, Effects of environment on intermediate temperature crack growth in superalloys, in: “Micro and Macro Mechanics of Crack Growth”, K. Sadananda, B.B. Rath, and D.J. Michel, eds., The Metallurgical Society of AIME, 177, (1981).
S. Floreen and R.H. Kane, An investigation of the creep-fatigue-environment interaction in a Ni-base superalloy, Fatigue of Eng. Mat. and Struct., 2: 401.
S. Floreen and R.H. Kane, Effects’ of environment on high temperature fatigue crack growth in a superalloy, Met. Trans. A, 10A: 1745 (November 1979).
D. Zheng and H. Ghonem, Oxidation-assisted fatigue crack growth behavior in alloy 718 - part II. applications, Fatigue Fract. Engng. Mater. Struct., 14, No. 7: 761 (1991).
D.J. Wilson, Relationship of mechanical characteristics and microstructural features to the time-dependent edge-notch sensitivity of inconel 718 sheet“, J. Eng. Mater. and Tech., 112 (April 1973).
D. Zheng and H. Ghonem, Influence of prolonged thermal exposure on intergranular fatigue crack growth behavior in alloy 718 at 650 °C, Met. Trans. A., 23A: 3169 (November 1992).
A. Diboine and A. Pineau, Creep crack initiation and growth in inconel 718 alloy at 650 °C, Fatigue Fract. Engng. Mater. Struct., 10, No. 2: 414 (1987).
J.P. Pedron and A. Pineau, The effect of microstructure and environment on the crack growth behavior of inconel 718 alloy at 650 °C under fatigue, creep and combined loading, Mater. Sci. and Eng., 56: 143 (1982).
H. Ghonem and D. Zheng, Depth of intergranular oxygen diffusion during environment-dependent fatigue crack growth in alloy 718, Mater. Sci. and Eng., A150: 151 (1992).
K. Sadananda and P. Shahinian, The effect of environment on the creep crack growth behavior of several structural alloys, Mater. Sci. and Eng., 43: 159 (1980).
H.H. Smith and D.J. Michel, Fatigue crack propagation and deformation mode in alloy 718 at elevated temperatures, in: “Ductility and Toughness Considerations in Elevated Temperature Service, MPC8”, G.V. Smith, ed., The American Society of Mechanical Engineers, NY, 225, (1978).
K. Sato and T. Ohno, Development of low thermal expansion superalloys, in: “Superalloys 1992”, 247, ASM Metals Park, OH (1992).
E.A. Wanner and D.A. DeAntonio, Development of a new controlled thermal expansion superalloy with improved oxidation resistance, in: “Superalloys 1992”, 237, ASM Metals Park, OH (1992).
NJ. Grant and A.W. Mullendore, “Deformation and Fracture at Elevated Temperatures”, The MIT Press, Cambridge, MA (1965)
R.M. Goldhoff, The evaluation of elevated temperature creep and rupture strength data: an historical perspective“, in: ”Characterization of Materials for Service at Elevated Temperatures, MPC-7“, G.V. Smith, ed., American Society of Mechanical Engineers, NY, 247 (1978).
H.E. Boyer, ed., “Atlas of Creep and Stress-Rupture Curves”, ASM Int., Metals Park, OH, 1.1–2.11 (1988).
H.E. Evans, “Mechanisms of Creep Fracture”, Elsevier Science Publishing Co., London (1984).
C.J. Moss and J.W. Martin, The effect of grain boundary y’ precipitation on the stress rupture behavior of nimonic PE16, Materials Forum, 15: 324 (1991).
D. J. Wilson, Sensitivity of the creep-rupture properties of waspaloy sheet to sharp-edged notches in the temperature range 1000–1400 deg F, J. Basic Eng., 13 (March 1972).
S. Nicol, “Stress-Rupture Properties of Incoloy 908 in Air”, B.S.M.E Thesis, Worcester Polytechnic Institute, (July 1993).
I.S. Hwang, R.G. Ballinger, M.M. Morra, and M.M. Steeves, Mechanical properties of incoloy 908 - an update, in: “Advances in Cryogenic Engineering (Materials)”, 38, F. Fickett and R.P. Reed, eds., Plenum Press, NY (1992).
I.P. Vasatis and R.M. Pelloux, “dc potential drop technique in creep stress rupture testing, J. of Met., 44 (October 1985).
ASTM Book of Standards, (E292–83).
J.H. Weber and H. Sizek, Private Communication from Inco Alloys Int., Huntington, WV, (May 27, 1993 ).
G.F. Vander Voort, “Metallography Principles and Practice”, McGraw-Hill, NY (1984).
M.S. Loveday, Practical aspects of testing circumferential notch specimens at high temperature, in: “Techniques for Multiaxial Creep Testing”, Elsevier, NY, 177 (1986).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1994 Springer Science+Business Media New York
About this chapter
Cite this chapter
Morra, M.M., Nicol, S., Toma, L., Hwang, I.S., Steeves, M.M., Ballinger, R.G. (1994). Stress Accelerated Grain Boundary Oxidation of Incoloy Alloy 908 in High Temperature Oxygenous Atmospheres. In: Reed, R.P., Fickett, F.R., Summers, L.T., Stieg, M. (eds) Advances in Cryogenic Engineering Materials . An International Cryogenic Materials Conference Publication, vol 40. Springer, Boston, MA. https://doi.org/10.1007/978-1-4757-9053-5_164
Download citation
DOI: https://doi.org/10.1007/978-1-4757-9053-5_164
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4757-9055-9
Online ISBN: 978-1-4757-9053-5
eBook Packages: Springer Book Archive