Publication Search

ASTM A36 steel has relatively low hardness and corrosion resistance, making surface treatment necessary to improve its material properties. This study aims to determine the effect of temperature and holding time variations in the pack carburizing process on the hardness, corrosion rate, and microstructure of ASTM A36 steel. The pack carburizing process was carried out using coconut shell charcoal as the carburizing medium with temperature variations of 850°C, 900°C, and 950°C and holding times of 20, 40, and 60 minutes, followed by quenching in distilled water. Hardness testing was conducted using the Rockwell B scale (HRB) method, corrosion rate testing was performed according to the ASTM G31 method, and microstructural observations were carried out using Scanning Electron Microscopy (SEM). The results showed that increasing the temperature and holding time improved the hardness and corrosion resistance of ASTM A36 steel. The highest hardness value was obtained at a temperature of 950°C with a holding time of 60 minutes, reaching 114.1 HRB. Microstructural analysis revealed the formation of a martensitic phase on the specimen surface after the carburizing process.

His study aims to investigate the effect of temperature variation in pack carburizing and quenching processes on the microstructure and surface hardness of Stainless Steel 316L. The pack carburizing process was conducted using activated carbon derived from robusta coffee grounds at temperatures of 700°C, 800°C, and 900°C with a holding time of 60 minutes. Subsequently, a quenching process was carried out using oil mixed with activated carbon to lock the diffused carbon. The material was tested for mass change, microstructure (via SEM), and surface hardness (using the Vickers method). The results show that increasing temperature significantly affects carbon diffusion and hardness improvement. The highest hardness value was obtained from the quenching process at 900°C with 330 HV, while pack carburizing at the same temperature resulted in 292 HV. The microstructure revealed more dominant Martensitic formation in the quenching process. Therefore, heat treatment with rapid cooling proves to be more effective in enhancing hardness and modifying the microstructure of Stainless Steel 316L.    

Stainless steel is an alloy steel with corrosion (rust) resistance properties. However, the good corrosion and wear resistance properties of stainless steel also require continuous improvement in its performance and service life, especially in highly aggressive environments. One approach to changing the material structure is by using a mixture based on natural carbon, such as robusta coffee grounds. Robusta coffee grounds will be converted into carbon using a pyrolysis process at a temperature of 1000°C with a holding time of 1 hour. This carbon will be used as a coating material on 316L stainless steel with a variety of pack carburizing and quenching processes and temperatures with a holding time of 1 hour, then it will undergo a testing process that includes: thermal conductivity testing, and corrosion rate testing. In the quenching process, the thermal conductivity value of 900°C has a thermal conductivity value of 20.556 W/m°C, 800°C has a thermal conductivity value of 19.669 W/m°C and a temperature of 700°C with a thermal conductivity value of 18.930 W/m°C. while in the pack carburizing process, the temperature of 900°C has a thermal conductivity value of 20.101 W/m°C, and 800° has a thermal conductivity value of 19.54684 W/m°C, while at 700°C the thermal conductivity value is 18.916 W/m°C. At the raw corrosion rate has a corrosion rate value of 7.614 mm/year, in the quenching process of 700°C has a corrosion rate of 12.781 mm/year, while the temperature of 900°C with a corrosion rate value of 18.401 mm/year, and in the pack carburizing process of 700°C has a corrosion rate value of 9.699 mm/year temperature 900°C with a corrosion rate value of 13.234 mm/year. The better process in thermal conductivity is quenching, because it has a faster time but has a high conductivity value, while for the best corrosion rate is the pack carburizing process because it has a smaller corrosion rate value compared to the quenching process

When welding, you don't have to connect two metal materials, you can also weld the thickness of the component. Steel is a metal material that can be used in the engineering field to make alloys of other metals so that they can have better material properties than the original metal material. One thing that can be done to increase resistance to wear is to increase the surface hardness of the workpiece. This research carried out an analysis to increase the hardness of the surface of low carbon steel after heat treatment for 60 minutes with variations in quenching media resulting from hardfacing using SMAW welding (shield metal arc welding) with DC+ and DC- polarities. The data analysis technique used in this research is specimen testing. The results obtained later by the research show that DC+ polarity has higher hardness in all specimens tested with a value of 418.66 VHN water quenching, 402.8 VHN oil quenching, 348 VHN non-treatment when compared with DC- polarity with a value of 405, 92 VHN quenching water, 374.02 VHN quenching oil and 323.38 VHN non-treatment. Quenching media with water obtained the highest hardness results with a value of 405.92 VHN.