Muttaqin Rahmat Pangaribawa

The cutting speed of laser cutting is predicted to affect the roughness of its object. However, its roughness characteristics still need to be determined to consider whether it is tolerant. The aspects of cutting products are studied intensely. Specific cutting styles with different plates like Eser thick versus velocity of the cut varied, affecting the fineness of surface cutting. However, a monitor showing frequency and period explained the more significant roughness. Those are predicted to be straightforward for checking samples. Using CMM and the Surface Roughness Tester, the cutting parameter and its process can be recommended for future applications. The brief used Eser plate cutting using CNC laser cutting with thicknesses of 3 mm, 4 mm, and 5 mm with cutting speeds of 1 m/min, 1.4 m/min, and 2 m/min. The best cutting speed was 2 m/min for a plate thickness of 3 mm, with an accuracy level of 98% and 98.51%, while the lowest Ra value was 6.51 µm. The plate thickness was 4 mm, the accuracy level was 98.05% and 98.77%, and the lowest Ra value was 4.183 µm. The plate thickness was 5 mm with an accuracy level of 97.7% and 97.99% and Ra of 8.995 µm. In the laser process, the thicker an object is, the lower its accuracy. In addition, the frequency of roughness sensitivity detection impacts more than its period during a standard operation.

Metal is an essential substance in the industrial world for supporting human life and technological advancement. Shaping and increasing metal’s ability involves the heat treatment process. This research aims to see how the microstructure and hardness of metal change after being heat treated with quenching and tempering medium at room temperature and ice. The experiment was conducted utilizing a heat treatment process involving heating the material to 840°C for 60 minutes, then quenching it with water and ice and tempering it at 200°C for 20 minutes. The hardness test employs the Rockwell Hardness Test method, which uses a 9-point hardness scale with the primary load (P) of 150kg-f. The observations for the micro test were in the form of density variations in ferrite, pearlite, and martensite crystal grains. Microstructure investigations showed the presence of martensite in the material after being heat-treated. The hardness test showed that the carbon steel material experienced a decrease in hardness from the initial value of 43.12 HRC to 39.32 HRC and 38.14 HRC after quenching water and ice water. The comparison of tempering has no significant effect on hardness with values of 40.63 HRC and 38.94 HRC tempering followed by water-quenching and ice water-quenching, respectively.