Abstract
Carburizing experiments were conducted at 927°C (1700°F) and 843°C (1550°F) using furnace atmospheres formed from methane and air and from butane and air introduced directly into the carburizing furnace. Gas flow rates were low to promote equilibration of the reaction products within the furnace. The air flow rate was held constant while the methane or butane flow was automatically regulated to maintain a constant oxygen potential, as measured by a zirconia oxygen sensor, within the furnace. In comparing the results of these experiments with earlier results obtained using propane and air, several differences were noted: (a) The methane content of the furnace atmosphere, measured by infrared analysis, was about twice as great when methane was the feed gas rather than propane or butane. This was true despite the fact that the mean residence time of the gas within the furnace was greater in the methane experiments. Methane appears to be less effective than propane or butane in reducing the CO2 and H2O contents to the levels required for carburizing. (b) There was a greater tendency for the CO content of the furnace atmosphere to decrease at high carbon potentials when methane is used instead of propane or butane. The decrease in CO content is due to hydrogen dilution caused by sooting in the furnace vestibule. These differences in behavior make propane or butane better suited than methane forin situ generation of carburizing atmospheres. However, there is no difference in the amount of carburizing occurring at a specified carbon potential when methane, propane, or butane are used as the feed gas in this process.
Similar content being viewed by others
References
C. A. Stickels, C. M. Mack, and M. Brachaczek:Metall. Trans. B, 1980, vol. 11B, pp. 471–79.
C. A. Stickels and C. M. Mack:Metall. Trans. B, 1980, vol. 11B, pp. 481–84.
C. A. Stickels, C. M. Mack, and J. A. Pieprzak:Metall. Trans. B, 1980, vol. 11B, pp. 485–91.
W. Gohring and C. H. Luiten:Heat Treatment of Metals, 1980, vol. 7, no. 4, pp. 79–82.
C. A. Stickels:Journal of Heat Treating, 1979, vol. 1, pp. 31–41.
D. R. Stull and H. Prophet:JANAF Thermochemical Tables, 2nd Edition, U. S. Department of Commerce (NSRDS-NBS 37), Washington, DC, June 1971.
J. Crank:The Mathematics of Diffusion, 2nd Edition Clarendon Press, Oxford, 1975, pp. 35–37, 60–61.
Author information
Authors and Affiliations
Additional information
J.A.Pieprzak, formerly a member of the Engineering and Research Staff
Rights and permissions
About this article
Cite this article
Stickels, C.A., Mack, C.M. & Pieprzak, J.A. bdGas carburizing of steel with furnace atmospheres formedin situ from methane and air and from butane and air. Metall Trans B 13, 613–623 (1982). https://doi.org/10.1007/BF02650019
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02650019