Article Periodicals » Materials Evaluation » Article
Comprehensive Evaluation of Aging Behavior in M250 Grade Maraging Steel Using Nondestructive Parameters

In order to nondestructively characterize the material (microstructural and mechanical) properties of M250 grade (UNS K93120) maraging steel, a study was designed to understand the influence of complex microstructural changes (precipitation of two intermetallics and austenitic reversion) of this steel on the mechanical properties and on three nondestructive testing (NDT) parameters. The NDT parameters (positron lifetime, magnetic Barkhausen emission peak root mean square voltage and ultrasonic velocity) and mechanical properties (yield strength and impact toughness) were measured on solution annealed (1093 K for 1 h) samples aged for various durations (755 K for 0.25 to 100 h). In the present study, an attempt has been made to compare the sensitivity and ability of the three NDT parameters in characterizing the developed microstructures. The decrease in discontinuity density due to discontinuity annihilation during initial aging and the increase in discontinuity density due to intermetallic precipitation upon longer aging could be revealed by positron lifetime. The study further showed that the precipitation of intermetallics during initial aging can be revealed by the ultrasonic velocity, and the austenitic reversion obtained upon longer aging can be revealed by the magnetic Barkhausen emission. However, none of the selected NDT parameters is found suitable for unambiguous identification of the technological regime (that is, optimum material properties achieved upon aging for 3 to 10 h). This paper demonstrates the applicability of a combination of two NDT parameters for qualifying the aging treatment corresponding to the technological regime in maraging steel.

References
Brasche, L.J.H., D.J. Bracci, D.C. Jiles and O. Buck, “Electrical and Mechanical Properties of Precipitation Hardened Al-Li Alloys,” Materials Science and Engineering A, Vol. 119, 1989, pp. 7–15. Brauer, G., L. Liszkay, B. Molnar and R. Krause-Rehberg‚“Microstructural Aspects of Neutron Embrittlement of Reactor Pressure Vessel Steels – A View from Positron Annihilation Spectroscopy,” Nuclear Engineering and Design, Vol. 127, 1991, pp. 47–54. Dobmann, G., Luigi Debarberis and Jean-Francois Cosle, “Aging Material Evaluation and Studies by Non-destructive Techniques (AMES-NDT) A European Network Project,” Nuclear Engineering and Design, Vol. 206, 2001, pp. 363–374. Floreen, S. and R.F. Decker, “Heat Treatment of 18% Ni Maraging Steel,” Source Book on Maraging Steels, R.F. Decker, ed., Metals Park, Ohio, ASM, 1979, pp. 20–32. Gur, C.H. and I. Yildiz, “Non-destructive Investigation on the Effect of Precipitation Hardening on Impact Toughness of 7020 Al-Zn-Mg Alloy,” Materials Science and Engineering A, Vol. 382, 2004, pp. 395–400. Jin, S., D. Huang and J.W. Morris, Jr., “Structure and Properties of a Microduplex Maraging Steel,” Metallurgical Transactions A, Vol. 7A, 1976, pp. 637–645. Kirkegaard, P., M. Eldrup, O.E. Mogensen and N.J. Pedersen, “Program System for Analysing Positron Lifetime Spectra and Angular Correlation Curves,” Computer Physics Communications, Vol. 68, 1981, pp. 307–335. Kumar A., T. Jayakumar, Baldev Raj and K.K. Ray, “Correlation between Ultrasonic Shear Wave Velocity and Poisson’s Ratio for Isotropic Solid Materials,” Acta Materialia, Vol. 51, 2003, pp. 2417–2426. Ledbetter, H.M. and D.T. Read, “Low-Temperature Elastic Properties of a 300-Grade Maraging Steel,” Metallurgical and Materials Transactions A, Vol. 8A, Nov. 1977, 1805–1808. Li, P., S.L. Chu, C.P. Chou and F.C. Chen, “Use of Ultrasonic Velocity for Nondestructive Evaluation of Ferrite Content in Duplex Fe-Mn-Al Alloy Steels,” Scripta Metallurgica et Materialia, Vol. 26, 1992, pp. 127–132. Miller, G.P. and W.I. Mitchell, “Structure and Hardening Mechanisms of 18% Nickel-Cobalt-Molybdenum Maraging Steels,” Journal of the Iron and Steel Institute, Vol. 203, 1965, pp. 899–904. Moore, K.D., P.L. Jones and H.F. Cocks, “A Positron Annihilation Study of the Precipitation Hardening Effects in a Maraging Steel,” Physica Status Solidi A, Vol. 72, 1982, pp. K223–K227. Peters, D.T. and C.R. Cupp, “The Kinetics of Aging Reactions in 18 Pct Ni Maraging Steels,” Transactions of the Metallurgical Society of AIME, Vol. 236, 1966, pp. 1420–1429. Rajaraman, R., P. Gopalan, B. Viwanathan and S. Venkadesan, “A Positron Annihilation Study of TiC Precipitation in Plastically Deformed Austenitic Stainless Steel,” Journal of Nuclear Materials, Vol. 217, 1994, pp. 325–328. Rajkumar, K.V., S. Vaidyanathan, Anish Kumar, T. Jayakumar, Baldev Raj and K.K. Ray, “Characterization of Aging-Induced Microstructural Changes in M250 Maraging Steel Using Magnetic Parameters,” Journal of Magnetism and Magnetic Materials, Vol. 312, 2007a, pp. 359–365. Rajkumar, K.V., Anish Kumar, T. Jayakumar, Baldev Raj and K.K. Ray, “Characterization of Aging Behavior in M250 Grade Maraging Steel Using Ultrasonic Measurements,” Metallurgical and Materials Transactions A, Vol. 38A, 2007b, pp. 236–243. Sha, W., A. Cerezo and G.D.W. Smith, “Phase Chemistry and Precipitation Reactions in Maraging Steels: Part I. Introduction and Study of Cocontaining C-300 Steel,” Metallurgical and Materials Transactions A, Vol. 24A, 1993, pp. 1221–1232. Vasudevan, V.K., S.J. Kim and C.M. Wayman, “Precipitation Reactions and Strengthening Behavior in 18 Wt Pct Nickel Maraging Steels,” Metallurgical and Materials Transactions A, Vol. 21A, 1990, pp. 2655–2668. Zaitseva, R.D. and M.D. Perkas, “Factors Determining the Ductility and Toughness of Maraging Steels,” Metal Science and Heat Treatment, Vol. 17, No. 9, 1975, pp. 729–736.
Metrics
Usage Shares
Total Views
21 Page Views
Total Shares
0 Tweets
21
0 PDF Downloads
0
0 Facebook Shares
Total Usage
21