Effect of Laser Scanning and Aging Treatment on Microstructure and Property of Austenitic Heat-Resistant Steel

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Abstract:

In order to improve surface properties, high chromium austenitic base heat-resistant cast steel was scanned with a 5kW continuous wave CO2 laser, the specimen was aged at the temperature of 600°C~900°C. The microstructure and phase composition of the specimen were analysed with optical microscopy, electronic microscope and X-ray diffractionse. The hardness was measured. The results show that as-cast structure of high chromium cast steel is coarse and non-homogeneous, and mainly consist of austenite, ledeburite and carbides. After laser surface melting, the section is divided into the melted zone consisted of fine austenite and carbides, the heat affected zone composed of austenite and eutectic carbides, and the base meta1. The melted zone is very fine structures with dendritic crystals, only at the bottom a cellular structure is observed. A continuous carbide network is located in the austenitic grain boundaries at the heat affected zone. Carbides particles distribute dispersed out, the hardness of melted zone increases 35% than the base metal after aging. The area and the hardness of various zones are related to the laser processing parameters. The hardening depth of melted zone and heat affected zone may be up to 200μm~300μm.

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Key Engineering Materials (Volumes 373-374)

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416-420

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March 2008

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© 2008 Trans Tech Publications Ltd. All Rights Reserved

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[1] J. W. Liu, L. ZH. Ouyang, C. P. Luo. et al. Materials for Mechanical Engineering, Vol. 26 (2002), pp.33-36 (in Chinese).

Google Scholar

[2] H. Y. Hao, S. R. Cao, Y. Hao. Metal Heat Treatment, Vol. 31 (2006), pp.65-67 (in Chinese).

Google Scholar

[3] G. Benkisser, M. Pohl, C. Hessing. Practical Metallography, Vol. 43 (2006), pp.381-395.

Google Scholar

[4] S. Kac, J. Kusinski. Surface and Coatings Technology, Vol. 180-181 (2004), pp.611-615.

DOI: 10.1016/j.surfcoat.2003.10.104

Google Scholar

[5] M. Carbucicchio, G. Palombarini, M. Rateo and G. Sambogna. Hyperfine Interactions, Vol. 112 (1998), pp.19-24.

DOI: 10.1023/a:1011007820797

Google Scholar

[6] M. S. F. Lima, H. Goldenstein. Journal of Crystal Growth, Vol. 208 (2000), pp.709-716.

Google Scholar

[7] C. Carboni, P. Peyre, G. BÉranger, C Lemaitre. Journal of Materials Science, Vol. 37 (2002), pp.3715-3723.

DOI: 10.1023/a:1016569527098

Google Scholar

[8] T. A. M. Haemers, D. G. Rickerby, F. Lanza, et al. Journal of Materials Science, Vol. 35 (2000), pp.5691-5698.

Google Scholar

[9] Q. M. Zhang, W. J. Liu. High Power Laser and Particle Beams, Vol. 18 (2006), pp.389-392 (in Chinese).

Google Scholar

[10] S. Fukumoto, W. Kurz. ISIJ International, Vol. 38 (1998), pp.71-77.

Google Scholar