Quality Control of Thin Films Deposited on Special Steels Used in Hydraulic Blades

Abstract:

The hydraulic turbine blades are made from stainless steels having a hard layer for the improvement of the hydro abrasive wear, corrosion resistance, and resistance to mechanical impacts in order to increase the reliability of the turbine. The thin films from stellite and tungsten carbide were obtained by the method: electrospark deposition because it has relatively low costs, are easy to obtain, the layers have a good adherence to support and the thickness can be variable in function of the established conditions. In this paper, the physical, chemical and mechanical properties of the samples will be determined using Scanning Electron Microscope (SEM), in order to emphasize the structure film-substrate and repartition of the deposition elements on the surface and in transversal section. Also, the samples were nondestructively tested using the electromagnetic sensor with metamaterials in order to establish the adherence of the thin films to the steel, proving the potential of this NDT techniques. The complex signal delivered by the sensor has been stored while scanning a 6x6 mm area. The processing algorithm involve the use of the bidimensional Fourier transform after filtering the initial signal using Walsh-Hadamard numerical filter.

• Periodical: Advanced Materials Research (Volume 1138)
• Pages: 62-68
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1138.62
• Online since: July 2016
• Authors: Catalin Andrei Tugui*, Petrica Vizureanu, Adriana Savin, Nicoleta Iftimie, Manuela Cristina Perju, Nicanor Cimpoeşu, Carmen Nejneru
• Keywords: Austenitic Steel, Electrospark Deposition, Hydraulic Turbine Blades, Nondestructive Testing

References

[1] M.C. Perju, P. Vizureanu, Chemical compounds analysis developed on the micro alloying area of coating layers obtained by impulse discharge method, REV. CHIM. 65 (2014) 694-696.

[2] D. Manova, S. Mändl, H. Neumann, B. Rauschenbach-Influence of grain size on nitrogen diffusivity in austenitic stainless steel, Surface and Coatings Technology, 201 (2007) 6686-6689.

DOI: 10.1016/j.surfcoat.2006.09.104

[3] A. Krella, Influence of cavitation intensity on X6CrNiTi18-10 stainless steel performance in the incubation period, Wear, 258 (2005) 1723–1731.

DOI: 10.1016/j.wear.2004.11.025

[4] M Grosse, M Niffenegger, D Kalkhof, Monitoring of low-cycle fatigue degradation in X6CrNiTi18-10 austenitic steel, Journal of nuclear materials, 296 (2001) 305–311.

DOI: 10.1016/s0022-3115(01)00547-5

[5] H. C Kim, D. K Kim, K. D Woo, I. Y Ko, I. J Shon, Consolidation of binderless WC–TiC by high frequency induction heating sintering, International Journal of Refractory Metals and Hard Materials 26 (2008) 48–54.

DOI: 10.1016/j.ijrmhm.2007.01.006

[6] S. Durdu, S.L. Aktuğ, K. Korkmaz, Characterization and mechanical properties of the duplex coatings produced on steel by electro-spark deposition and micro-arc oxidation, Surface and Coatings Technology, 236 (2013) 303-308.

DOI: 10.1016/j.surfcoat.2013.10.004

[7] D. Liu, W. Gao, L. Zhengwei, Z. Haifeng, H. Zhuangqi, Electro-spark deposition of Fe-based amorphous alloy coatings, Materials Letters 61, (2007) 165-167.

DOI: 10.1016/j.matlet.2006.04.042

[8] R. Grimberg, A. Savin, J. Rebello, Electromagnetic examination of hydrogen attack in AISI 4340 steel, Electromagnetic Nondestructive Evaluation (XVI), Studies in Applied Electromagnetics and Mechanics, 38, (2013) 270–277.

[9] A. Marion An Introduction to Image Processing, Chapman and Hall, 1991, Chap. 9.

[10] R. Scheibler, S. Haghighatshoar, M. Vetterli, A Fast Hadamard Transform for Signals With Sublinear Sparsity in the Transform Domain., IEEE Transactions on Information Theory, 61(4), (2015) 2115-2132.

DOI: 10.1109/tit.2015.2404441

[11] J. Wang, H. Meng, H. Yu, Z. Fan, D. Sun, Characterization and wear behavior of WC-0. 8 Co coating on cast steel rolls by electro-spark deposition, International Journal of Minerals 16 (2009) 707-713.