Effects of Carburizing Process Variables on Mechanical and Chemical Properties of Carburized Mild Steel


 Carburizers, hardness, tensile, carburizing time and temperature, pack carburizing, quenching and  tempering properties.

How to Cite

A. Oyetunji, & S.O. Adeosun. (2021). Effects of Carburizing Process Variables on Mechanical and Chemical Properties of Carburized Mild Steel. Journal of Basic & Applied Sciences, 8(2), 319–324. https://doi.org/10.6000/1927-5129.2012.08.02.11


This work evaluates the suitability of using palm kernel shell, animal bone (mammalian bones from cattle) and sea shell (oyster shell) materials as carburizers for case hardening of 0.078%C mild steel. The mild steel sample used in this study sourced from universal steel company, Ikeja Lagos Nigeria was cut into suitable sizes using hacksaw machine for tensile and hardness tests. The carburizing media used were milled into fine powder while Barium trioxo (iv) carbonate (VI) (BaCO3) was used as an energizer in the carburizing process. Three rectangular stainless steel plate boxes were fabricated to accommodate each of the steel samples and carburized. A calculated amount of each carburizer was weighed into each of the stainless steel boxes and 20 wt % of BaC03 was mixed with each of them. Mild steel samples were covered completely in each of the boxes with the mixture of the carburizer and energizer placed in the furnace chamber. The carburizing temperatures varied between 700 - 1100oC while the holding time varied between 1-5 hrs. The boxes and its contents were allowed to cool down to room temperature in the furnace after carburization. All samples were heated to 850oC after been soaked for 30 minutes at this temperature and oil quenched. This was to increase the hardness of the case. Fifteen (15) of these samples were further tempered at 350oC for 2hrs to relieve the stress built up during quenching. Hardness test, tensile strength tests and chemical analysis were carried out on the samples. It was observed that the hardness values of the untempered samples are superior to the tempered ones at carburizing temperatures of 7000C, 8000C and 9000C. On the other hand, the tensile strengths of the tempered samples are higher relative to the untempered samples at carburizing temperatures of 7000C, 10000C and 11000C. The results of the carbon analysis show that palm kernel shell and animal bone are potentially suitable to be used as a carburizing media than the sea shell at high temperatures (above 10000C) with holding time above 1 hr.



Child HC. Surface Hardening of Steel. Oxford University Press. UK 1980; pp.10-24

Higgins RA. Engineering Metallurgy. (part 1, Applied physical metallurgy).5th ed. Kent: ELBS; Edward Arnold Publishers Ltd. 1991; pp. 40-162.

Prime MB, Prantil VC, Rangaswamy P, García FP. In: Böttger AJ, Delhez R, Mittemeijer EJ, Eds. Residual Stress Measurement and Prediction in a Hardened Steel Ring. Materials Science Forum; Residual Stress ECRS 5. Stamford: Thomson Scientific; 2006; pp. 223-228.

Craig F. Case hardening In a Home Garage. 2006.

Stephen MC, Edward LL. ASM Handbook- Heat Treating, 1991; Vol. 4.

Schimizu N, Tamura I. (1997) An examination of the relation between quench-hardening behaviour of steel and cooling curve in oil. Trans ISIJ 1978; 18: pp. 445-50.

Kirkaldy JS, Feldman SE. J Heat Treating 1989; 7(1): 57-64. http://dx.doi.org/10.1007/BF02833188

Rudnev VD. Loveless RC, Black M. Handbook of Induction Heating, Marcel Dekker, Inc., New York, 2003; pp. 39-43.

Rakhit AK. Heat Treatment of Gears: A Practical Guide for Engineers, ASM International, Metals Park, OH, 2000; pp. 44-50, 86-90.

Smith WF. Structure and Properties of Engineering Alloys, 2nd ed., McGraw-Hill, Inc., New York, 1993; pp. 132-141.

Rajan TV, Sharma CP, Sharma A. Heat Treatment Principles and Techniques. New Delhi: Prentice Hall 1994.

Denis S. Coupled temperature stress, phase transformation calculation model numerical illustration of the internal stresses evolution during cooling of a eutectoid carbon steel cylinder. Metallurgical Transaction A; 1987; 18A: 1203-87. http://dx.doi.org/10.1007/BF02647190

Leblond JB. Mathematical modeling of transformation plasticity in steels II: Coupling with strain hardening phenomena. Int J Plast 1989; 5(6): 573-1. http://dx.doi.org/10.1016/0749-6419(89)90002-8

Wang KF, Chandrasekar S, Yang HTY. Experimental and computational study of the quenching of carbon steel. Intl Jl Manufact Sci Eng 1997; 119(3): 257-65. http://dx.doi.org/10.1115/1.2831102

Liu CC, Xu X, Liu ZA. FEM modeling of quenching and tempering and its application in industrial engineering. Finite Elements in Analysis and Design 2003; 39(11): 1053-70. http://dx.doi.org/10.1016/S0168-874X(02)00156-7

Xu DH, Kuang ZB. A study on the distribution of residual stress due to surface induction hardening. Int J Eng Mater Technol 1996; 118(2): 571-75. http://dx.doi.org/10.1115/1.2805958

Aramide FO, Ibitoye SA, Oladele IO, Borode JO. Effects of Carburization Time and Temperature on the Mechanical Properties of Carburized Mild Steel, Using Activated Carbon as Carburizer. Mater Res 2009; 12(4): 483-87. http://dx.doi.org/10.1590/S1516-14392009000400018

Shewmon GP. Diffusion in solids, series in material science and Engineering. Tokyo: McGraw Hill; 1963.

Oyetunji A, Alaneme KK. Influence of the Silicon Content and Matrix Structure on the Mechanical Properties of Al-Si Alloy. West Indian J Eng 2005; 28(1): 36-44.