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.

One of the various salted egg products with smoking methods is smoked salted eggs which have a distinctive aroma and taste. This study aims to determine the effect of smoking and storage time  and its  interaction on  smoked salted  eggs  with on  physical  and  chemical  properties, total microbes as well. This research is experimental by using ducks eggs and a mixture of coconut shells and fibers, and rice husks as smoke fuel. The experimental design used is Randomized Complete Block Design (RCBD) with a 3x5 factorial pattern. As the first factor (P) is the smoking time which consists of P0= 0 hours, P1= 12 hours, P2= 15 hours while the second factor (H) is the storage time which consists of H0= 0 days, H1=7 days, H2= 14 days, H3= 21 days, and H4= 28 days. The variables observed were egg weight, albumen and yolk pH, moisture content, protein, and total microbial colony of smoked salted eggs. The results of the study were that the smoking time of 15 hours resulted in the lowest weight of smoked salted eggs (56.13g), while the storage time decreased the pH of albumen. Smoked salted duck eggs have a moisture content of 58.435-67.149%. The length of smoking increases the protein level. Salted duck eggs with a smoking time of 15 hours have the highest protein content, which is 15.39%. however, the duration of smoking and storage did not affect the total microbes of smoked salted eggs and there was no interaction between the duration of smoking and the duration of storage on the physical, chemical and total microbial properties.