Oktavia, A., Tabitha, A. K. ., Drajat, B. ., & Pujiyulianto, E. . (2026). Analysis of Hardness Test and Microstructure Test of R.54 Type Railway Rail with Variations in Heat Treatment Cooling Media. Journal of Engineering and Scientific Research, 7(2), 63–77. https://doi.org/10.23960/jesr.v7i2.175