An In Situ High-Temperature X-Ray Diffraction Study of Phase Transformations in Maraging 300 Steel


Article Preview

An in situ high-temperature X-ray diffraction (HTXRD) study in maraging 300 steel was carried out to study the martensite to austenite transformation and effect of time of exposure in the austenite reversion below austenite start temperature. Solution annealed materials were subjected to controlled heating-holding cycles. The first sample was heated at a rate of 10 oC/min from room temperature to 800 oC, showing that the microstructure is completely martensitic (α’110) until 600 oC. From 650 oC until 800 oC, the microstructure is gradually changing from martensitic to austenitic, showed by the increasing peaks of γ111 and reducing peaks of α’110. At 800 oC the microstructure is completely austenitic (γ111). Another sample was heated at 10 oC/min from room temperature to 600 oC and held for 4 hours. At 600 oC, at 0 h time of exposure, only a martensitic peak was observed. An austenite peak can be observed after some time of exposure at this temperature. The volume fraction of austenite increased with increasing time of exposure at 600 oC, reaching 50/50 volume fraction after 4 hours of exposure. XRD diffraction patterns for the same sample that was held for 4 hours at 600 oC and then cooled down in air to room temperature showed the same intensity of austenite and martensitic peaks found in situ at 600 oC for 4 hours (retained austenite), with the volume fraction of 50/50 of austenite and martensite phases. The HTXRD technique can be used to identify and quantify martensite to austenite transformation and austenite retention.



Edited by:

Prof. Andreas Öchsner, Prof. Graeme E. Murch, Ali Shokuhfar and Prof. João M.P.Q. Delgado




A. G. Reis et al., "An In Situ High-Temperature X-Ray Diffraction Study of Phase Transformations in Maraging 300 Steel", Defect and Diffusion Forum, Vol. 371, pp. 73-77, 2016

Online since:

February 2017




[1] E. Pereloma and D.V. Edmonds: Phase transformations in steels: Diffusionless transformations, high strength steels, modelling and advanced analytical techniques, Woodhead Publishing Limited, New Delhi, (2012).

[2] W. Sha and Z. Guo: Maraging steels: Modelling of microstructure, properties and applications, Woodhead Publishing Limited, Boca Raton, (2009).

[3] A. M. Hall and C.J. Slunder: The metallurgy, behavior, and application of the 18-percent Nickel Maraging steels: A survey. Washington, D.C.: NASA - Battelle Memorial Institute, 1968. (NASA SP-5051).

[4] M. Schmidt and K. Rohrback: Heat treating of Maraging Steels, in: ASM Handbook Committee. ASM Handbook: Heat treating, tenth ed., v. 4, ASM International, Materials Park, 1991, pp.528-548.

[5] U.K. Viswanathan, G.K. Dey and V. Sethumadhavan: Mater. Sci. Eng. A Vol. 398 (2005), p.367.

[6] A.G. Reis, D.A.P. Reis, A.J. Abdalla and J. Otubo: Mater. Charact. Vol. 107 (2015), p.350.

[7] J.M. Pardal, S.S.M. Tavares and M.P. Cindra Fonseca: J. Mater. Sci. Vol. 41 (2006) p.2301.

[8] R. Kapoor, L. Kumar and I.S. Batra: Mat. Sci. Eng. A. Vol. 352 (2003) p.318.

[9] L.G. Carvalho, M.S. Andrade, R. L Plaut, F.M. Souza and A.F. Padilha: Mater. Res. Vol. 16-4 (2013) p.740.

[10] A.G. Reis, D.A.P. Reis, A.J. Abdalla, J. Otubo, H.R.Z. A Sandim: IOP Conf. Ser.: Mater. Sci. Eng. Vol. 97 (2015) p.012006.


[11] B.D. Cullity, S.R. Stock, Elements of X-Ray Diffraction Third Ed, Prentice-Hall, New Jersey, (2001).