A Teaching-Oriented Approach to Post-Cooling Mechanical Evaluation of Welded Joints by Students

M. Jaya Ramadhan; Kartia  Ramdania

Authors

M. Jaya Ramadhan Program Study Conversion Energy Engineering, Polytecnic of Medan Medan, Indonesia
Kartia Ramdania Program Study Conversion Energy Engineering, Polytecnic of Medan Medan, Indonesia

Keywords:

Teaching-Oriented Experiment, Welded Joints Cooling Rate, Mechanical Evaluation

Abstract

This study explores a teaching-oriented approach to post-cooling mechanical evaluation of welded joints, aiming to integrate quantitative metallurgical analysis with experiential learning in engineering education. The research sought to enhance students’ understanding of the relationship between thermal processes and mechanical behavior through direct involvement in experimental procedures. A quantitative method was employed using welded steel specimens subjected to two cooling conditionsnatural air cooling and controlled air jet cooling. Mechanical properties, including tensile strength, hardness, and grain size, were measured, and the data were analyzed statistically using analysis of variance and correlation tests to determine the influence of cooling rate on material performance. The results showed that controlled cooling produced finer grain structures and led to a 6–8% improvement in tensile strength and hardness compared to natural cooling. These findings confirm classical metallurgical theories regarding the Hall–Petch relationship and microstructural strengthening mechanisms. Beyond material analysis, the study demonstrated that student participation in quantitative experimentation fosters critical thinking, data literacy, and scientific reasoning. This integrated model effectively bridges the gap between theoretical instruction and professional engineering practice. The study concludes that combining quantitative evaluation with a teaching-oriented framework provides a replicable model for modern engineering curricula, promoting both technical competence and cognitive development. Future studies are encouraged to expand this model to diverse materials and thermal conditions to strengthen its generalizability.

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