Thermogravimetric Study of the Oxidation Behaviour of Sintered Stainless Steels: Influence of Powder Size and Composition

Abstract:

The oxidation resistance at high temperature of the sintered stainless steels highly depends on their porosity and composition. In this work, 9 different powder mixes of gas atomized (ga) and water atomized (wa) particles were prepared. wa ferritic AISI 434L was used as base material, mixed in different amounts (5-20% by wt.) with ga austenitic AISI 316L or ga ferritic AISI 430L. All materials were vacuum sintered at two temperatures (1175 and 1225 °C). Thermogravimetric curves of the materials at 800 °C were obtained. Logarithmic curves are used to fit the experimental mass gains of PM steels. The addition of ga powder to the wa powder reduces the kinetic constant (k) in a remarkable way. The value of k depends on the amount of small pores that become blocked by the oxides when the exposure at high-temperature takes place. For similar porosity values, pure ferritic alloys show slower oxidation kinetic than duplex stainless steels.

• Periodical: Materials Science Forum (Volumes 727-728)
• Pages: 108-113
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.727-728.108
• Online since: August 2012
• Authors: Cristina Moral, Asuncion Bautista
• Keywords: High-Temperature, Oxidation Kinetic, Porosity, Powder metallurgy, Stainless Steel (SS)

References

[1] G.Y. Lai: High-Temperature Corrosion of Engineering Alloys, 3rd ed. (ASM International, OH, 1997).

[2] S. Molin, B. Kusz, M. Gazda and P. Jasinski: J. Power Sour. Vol. 181 (2008), p.31.

[3] A. Bautista, E. Arahuetes, F. Velasco, C. Moral and R. Calabrés: Oxid. Met. Vol. 70 (2008), p.267.

DOI: 10.1007/s11085-008-9120-3

[4] S.K. Mukerherjee and G.S. Upadhayaya: Oxid. Met. Vol. 23 (1985), p.177.

[5] S.O. Shah, J.R. McMillen, P.K. Samal and E. Klar: SAE Technical Paper Nº 980314, Society of Automotive Engineers, Warrendale, PA (1998).

[6] A. Bautista, F. Velasco, M. Campos, M.E. Rabanal and J.M. Torralba: Oxid. Met. Vol. 59 (2003), p.373.

[7] A. Bautista, F. Velasco and J. Abenojar: Corros. Sci. Vol. 45 (2003), p.1343.

[8] C. Moral, A. Bautista and F. Velasco: Corros. Sci Vol. Vol. 51 (2009), p.1651.

[9] C. Padmavathi, A. Upadhyayaa and D. Agrawal: Scripta Mater. Vol. 57 (2007), p.651.

[10] A. Bautista, C. Moral, F. Velasco, C. Simal and S. Guzmán: J. Mater. Process. Techn. Vol. 189 (2007), p.344.

[11] A. Bautista, C. Moral, G. Blanco and F. Velasco: Powder Metall. Vol. 49 (2006), p.265.

[12] D.L. Douglass, F. Gesmundo and C. Asmundis: Oxid. Met. Vol. 26 (1986), p.213.

[13] R. Baboian and G.D. Smith (Eds. ): Corrosion test and standars: Aplication and Interpretation", Cap. 16. 1st Ed. American Society for Testing and Materials, Philadelphia, USA (1995), pp.149-157.

[14] F. Velasco, A. González-Centeno and A. Bautista: Mater. Sci. Forum Vols. 461-464 (2004), p.1149.