INTERCRITICAL HEAT TREATMENT EFFECTS ON LOW CARBON STEELS QUENCHED FROM INTERMEDIATE TEMPERATURE AUSTENITIZATION

Authors

  • PO Offor Department of Metallurgical and Materials Engineering, University of Nigeria, Nsukka.
  • BA Ezekoye Department of Physics and Astronomy, University of Nigeria, Nsukka.

DOI:

https://doi.org/10.4314/njt.282.120

Keywords:

Mechanical properties, intercritical heat-treatments, austenitizing temperature, intermediate temperature

Abstract

Six low carbon steels containing carbon in the range 0.13-0.18wt%C were studied after intercritical quenching, intercritical quenching with low temperature tempering, intercritical annealing and intercritical normalizing using specimens originally quenched from intermediate austenitizing temperature (9500C). The studies also examined the microstructure of the intermediate austenitizing temperature (9500C) quenched specimens. The intercritical and tempering temperatures were 7400C and 1800C respectively. Comparison of the mechanical properties of the intercritically heat treated specimens with those of the intermediate austenitizing temperature specimens showed that intercritical quenching with low temperature tempering reduced the ultimate tensile strength and hardness  and increased the percentage reduction in area and the notch impact toughness. Intercritical annealing and intercritical normalizing increased the yield strength, ductility and toughness but decreased the ultimate tensile strength and hardness.

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Section

Research papers of General Interest

How to Cite

INTERCRITICAL HEAT TREATMENT EFFECTS ON LOW CARBON STEELS QUENCHED FROM INTERMEDIATE TEMPERATURE AUSTENITIZATION. (2008). Nigerian Journal of Technology, 28(2), 39-47. https://doi.org/10.4314/njt.282.120