Effect of Cooling Medium and Tempering on Microstructures and Hardness of SK3 High Carbon Steel

Ridhwan Jumaidin; Iffa Marina Jopri; Rafidah Hasan; Muhammad Ilman Hakimi Chua Abdullah; Mohamed Saiful Firdaus Hussin; Alia Ruzana Aziz; Abdul Rafeq Saleman; Febrian Idral

Authors

Ridhwan Jumaidin Fakulti Teknologi Kejuruteraan Mekanikal dan Pembuatan, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
Iffa Marina Jopri Centre for Advanced Research on Energy,Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 DurianTunggal, Melaka, Malaysia
Rafidah Hasan Centre for Advanced Research on Energy, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 DurianTunggal, Melaka, Malaysia
Muhammad Ilman Hakimi Chua Abdullah Centre for Advanced Research on Energy,Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 DurianTunggal, Melaka, Malaysia
Mohamed Saiful Firdaus Hussin Centre for Advanced Research on Energy,Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 DurianTunggal, Melaka, Malaysia
Alia Ruzana Aziz Department of Aerospace Engineering, KhalifaUniversity of Science and Technology (KUST), 127788 Abu Dhabi, United Arab Emirates
Abdul Rafeq Saleman Centre for Advanced Research on Energy,Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 DurianTunggal, Melaka, Malaysia
Febrian Idral Centre for Advanced Research on Energy,Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 DurianTunggal, Melaka, Malaysia

Keywords:

High carbon steel, heat treatment, annealing, quenching, tempering

Abstract

This paper presents a study on the effect of heat treatments i. e annealing, quenching, normalizing, and tempering on the characteristics of SK3 high carbon steel. The specimens were heated to austenitizing temperatures at 760ºC, 840C, 920C, 1000C and 1080C, before cooled by using different cooling medium i.e.oil quenching, air cooling, and furnace cooling. Tempering process was conducted on the quenched specimen by reheating at 500C and cooled to room temperature. Material characterization techniquessuch as hardness test and morphological investigation were carried out for all specimens. The heat treatment has significantly improvedthe hardness of the material. The quenched specimen (rapid cooling) shows the highest increment of hardness by 709%. This was followed by the normalized specimen (moderate cooling) and annealed specimen (slow cooling) which shows 425% and 170% of increment respectively. However, tempering treatment on the quenched specimen has shown a slight decrease in the hardness value.In terms of microstructure, the annealed specimen produced coarse grain size while the quenched specimen produced a fine grain size. The hardness of the specimen subjected to tempering process is lower than that of quenching process.