Paper Titles
Experimental Methodology Destined to Establish the Frequency Response Function (FRF) between a Dynamic Force and the Signals Emitted by a Piezoelectric Dynamometer
p.85
Failure Prediction in Stretched Sheets of Aluminium 2024-T3
p.91
Feature Selection for Tool Condition Monitoring in Turning Processes
p.97
Fixture Design Process Automation for Coordinate Measuring Machines: A Knowledge-Based Approach
p.103
Growth Kinetics of Hardened Layers Produced during Nitriding in Ammonia Gas Environments
p.109
High Productivity Machining Centre Evaluation in Collaborative Engineering Environment
p.115
Improving NC Milling Skills through Practise of Simulated Work
p.121
Influence of the Machining Parameters on Workpiece Roundness Error during Turning Operations
p.127
Investigation on the Predictive Model for Burr in Laser Cutting Titanium Alloy
p.133

Growth Kinetics of Hardened Layers Produced during Nitriding in Ammonia Gas Environments

Article Preview

Abstract:

In gas nitriding the thickness of the case depth is reported to increase parabolically with processing time and ammonia content in the NH3/H2 gas mixture which consequently increases the thickness of undesirable surface iron-nitride (white layer). In this investigation two commercial grade low alloy steels were nitrided in gas atmospheres containing 10 to 80% ammonia at 4700, 5200 and 5700C for 6 to 96 h. A metallographic technique was used to reveal different zones of the nitrided surface and the thickness of the diffusion zone was recorded using microscope. The growth kinetics of the diffusion layer of these two steels were analyzed and compared with that of 3% chromium (En40B) steel from literature. The results of the investigation conclusively suggest that the growth rate of the nitrided layer for both steels reached to a maximum with the increase of ammonia content in the gas mixture up to an optimum level where the thickness of the white layer is a minimum. However, the growth rates of the nitrided case are different for different steels.

You might also be interested in these eBooks
Advances in Materials Processing Technologies, 2006 View Preview

Info:

Periodical:

Materials Science Forum (Volume 526)

Pages:

109-114

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.526.109

Citation:

Cite this paper

Online since:

October 2006

Authors:

S. Mridha

Keywords:

Ammonia, Diffusion Layer, Gas Nitriding, Growth Rate, Nitriding Potential, White Layer

Export:

RIS, BibTeX

Price:

Permissions CCC:

Request Permissions

Permissions PLS:

Request Permissions

Сopyright:

© 2006 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

References

[1] K. Hussain, A. Tauqir, A. ul Haq and A. Q. Khan, Influence of Gas Nitriding on Fatigue Resistance of Maraging Steel, International Journal of Fatigue, 1999, 21, 163-168.

DOI: 10.1016/s0142-1123(98)00063-2

Google Scholar

[2] G. S. Fox-Rabinvich, L. Shuster and G. K. Dosbaeva, Impact of Ion Modification of HSS Surfaces on the Wear Resistance of Cutting Tools with Surface Engineered Coatings, Wear, 294 (2001), 1051-1058.

DOI: 10.1016/s0043-1648(01)00829-8

Google Scholar

[3] M. D. Zlatanvic, A. M. Kunosic, R. B. Belosevac and N. V. Popovic, Plasma Deposition of Hard Coatings-duplex Treatment, Mater. Sci. Forum, 214 (1996), 179-188.

Google Scholar

[4] H. Dong, Y. Sun and T. Bell, Enhanced Corrosion Resistance of Duplex Coatings, Surf. Coat. Technol., 90 (1997), 91-101.

DOI: 10.1016/s0257-8972(96)03099-x

Google Scholar

[5] T. Bjork, R. Mestergard, S. Hogmerk, J. Bergstrom and P. Hedenqvist, Physical Vapour Deposition Duplex Coatings for Aluminium Extrusion Die, Wear, 225-229 (1999), 1123-1130.

DOI: 10.1016/s0043-1648(99)00089-7

Google Scholar

[6] Y. Sun, and T. Bell, The Role of Oxidation in the Wear of Plasma Nitrided and PVD TiN Coated Steel, Wear, 166 (1993), 119.

DOI: 10.1016/0043-1648(93)90286-u

Google Scholar

[7] M. Van Stappen, M. Kerkhofs, C. Qaeyhaegens and I. Stals, Introduction in Industry of Duplex Treatment Consisting of Plasma nitriding and PVD of TiN, Wear 153 (1992), 655-661.

DOI: 10.1016/0257-8972(93)90314-e

Google Scholar

[8] A. E. Zeghni and M. S. J. Hashmi, The Effect of Coating and Nitriding on the Wear Behaviour of Tool Steels, Journal of Materials Processing Technology, 2004, 155-156, 1918-(1922).

DOI: 10.1016/j.jmatprotec.2004.04.281

Google Scholar

[9] K. Hock, H. J. Spies, B. Larich and G. Leonhardt, Wear Resistance of Prenitrided Hard Coated Steels for Tools and Machine Components, Surf. Coat. Technol., 88 (1996), 44-49.

DOI: 10.1016/s0257-8972(96)02914-3

Google Scholar

[10] M. Bader, H. J. Spies, K. Hock, E. Broszeit and H. J. Schroder, Properties of Duplex Treated (Gas Nitriding and PVD -TiN, -Cr2N) Low Alloy Steel, Surface and Coating Technology, 1998, 98, 891-896.

DOI: 10.1016/s0257-8972(97)00312-5

Google Scholar

[11] G. S. Fox-Robinovich, A. I. Kovalev, S. N. Afanasyev, Wear Characteristic of Surface Engineered High Speed Steel Cutting Tools, Wear 201 (1996), 38-44.

DOI: 10.1016/s0043-1648(96)07203-1

Google Scholar

[12] B. J. Lightfoot and D. H. Jack,. Heat Treatment '73, 1975, London, The Metals Society, 59-65.

Google Scholar

[13] S. Winnik, Ph.D. Thesis, (The effects of process variables oil the nitriding behaviour of chromium steels), Leeds University, (1979).

Google Scholar

[14] B. J. Lightfoot, Ph.D. Thesis, Nitriding of some chromium irons and steels, Leeds University, (1973).

Google Scholar

[15] S. Mridha and D. H. Jack, The Effect of Prior Heat Treatment and Processing Variables on the Hardened Layer of the Nitrided En40B Steel, International Surface Modification Technologies Conference, 12-15 October 1998, Rosemont Convention Centre, Rosemont, Illinois, USA.

Google Scholar

[16] K. E. Thelning, Steel and its Heat Treatment, Cox and Wyman Ltd., 1975, 406.

Google Scholar

[17] S. Mridha and D.H. Jack, Etching Techniques for Nitrided Iron and Steels, J. of Metallography, 15, p.63175, 1982, USA.

DOI: 10.1016/0026-0800(82)90020-9

Google Scholar

[18] S. Mridha and D.H. Jack, Characterization of a Nitrided 3% Chromium Steel, J. of Metal Science, 16, pp.398-404, 1982, UK.

DOI: 10.1179/msc.1982.16.8.398

Google Scholar

[19] P. H. Emmett, S. B. Hendricks and S. Brunauer, J. Am. Chem. Soc., 1930, 52, 1456-1465.

Google Scholar

[20] C. Wagner, Z. Electrochem., 1959, 63, 772-782.

Google Scholar

[21] E. J. Mittemeijer and M. A. J. Somers, Surface Engineering, 13 (1997), 483-497.

Google Scholar

[22] M. A. J. Somers and E. J. Mittemeijer, Surface Engineering, 3 (1987), 123-137.

Google Scholar

[23] K. Schwerdtfeger, P. Grieveson and E. T. Turkdogan, Trans. AIME, 245 (1969), 2461-2466.

Google Scholar

[24] S. Mridha, To be published.

Google Scholar