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![Theoretical graph of Jominy test [4]](profile/Omolayo-Ikumapayi/publication/344237711/figure/fig2/AS:935642200551424@1600085892154/Theoretical-graph-of-Jominy-test-4.jpg)
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![Fig. 3. Theoretical graph of Jominy test [4]](profile/Omolayo-Ikumapayi/publication/344237711/figure/fig2/AS:935642200551424@1600085892154/Theoretical-graph-of-Jominy-test-4_Q320.jpg)
![Fig. 5. Showing a phase diagram [6].](profile/Omolayo-Ikumapayi/publication/344237711/figure/fig4/AS:935642200567820@1600085892544/Showing-a-phase-diagram-6_Q320.jpg)
In this study, the effect of cooling rate on the hardenability of different steels materials following ASTM A255 standard test methods using the Jominy end quench technique. Steel hardening is implemented to enhance strength and wear characteristics. A reasonable carbon and alloy content are one of the guiding principles for the hardening. If the c...
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... carbon content increases, it influences the end of martensite formation relatively to the martensite start formation , this occurs as the temperature is lowered as shown in Fig. 2. In the above figure, it can be seen that as the carbon increases above 0.6 %, the transformation to martensite is likely to be incomplete if the process is halted at 0°C or higher" [4]. 3 shows an ideal graph of the Jominy test. The Rockwell scale decreases as the position away from the quenched end increases, this can be attributed to different factors especially grain size as well as cooling rate [5]. ...
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... Steel is the metallic alloy mostly used in industry, because of this, steel hardenability has major importance in industrial manufacturing. The advantage of using the Jominy test in manufacturing industries is to know which steel has the greatest hardenability for industrial purposes [11]. ...
This work provides the description of an experimental study for assessing the hardness of metallic test samples, subjected to the Jominy End-Quench Hardenability Test, by employing typical microhardness tests. Additionally, experimental measurements of the propagation velocity of ultrasound in the test samples were correlated with the microhardness results. A systematic protocol is presented for undergraduate mechanical engineering lectures, addressing the development of experiments, including the sorting and analysis of the resulting data; also, its impact on the expected competencies and abilities of the students is discussed. Several test samples of AISI 4140 steel were used for three experimental sets: heat-treated with the Jominy End-Quench Hardenability Test, fully tempered, and non-treated samples. All samples were evaluated by using typical microhardness tests and ultrasonic pulse-echo measurements to quantify their hardness at multiple locations. The proposed methodology not only strengthened some of the different required abilities of engineering students but also introduces a new procedure, using ultrasonic signals, to estimate hardness in undergraduate programs. The obtained results show a significant correlation between the experimental data from microhardness and ultrasonic measurements, with a maximum precision of -96.36% (inverse correlation) within the studied range. A discussion is provided regarding the means of improving the skills of undergraduate students in the course of Material Science, including experimental mechanical testing abilities through these systematic methods.
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