Influence of Reheating in Pack Carburizing Process with Bamboo Charcoal and Cow Bone Powder Media for Hardness Number and Impact Strength Low Carbon Steel

摘要

Pack Carburizing process is the process of adding carbon element (C) into the metal, especially on the surface of the material where the carbon element is obtained from materials containing carbon so that the metal hardness can increase. Carburizing research that has been done with teak wood charcoal media and BaCO_3 or NaCO_3. The Pack Carburizing process is high costly. This study uses an alternative carburizing media in the form of bamboo charcoal and cow bone powder. The aim of this research is to know the difference of toughness value and hardness of low carbon steel which have undergone pack carburizing process, and reheating process of low carbon steel. The pack carburizing process was carried out at temperature 900°C for 7 hours carburizing time. The hardening process was carried out by reheating the specimens at 900°C, for 50 minutes holding time, cooled with air-cooled media, water and water + 30% salt. Then tested toughness and hardness test. While Scanning Electron Microscope (SEM) test is done to see the carbon diffusion after carburizing process in the form of a picture or photo. From this study it was concluded that with 7 hours of carburizing time, carbon diffusion and highest surface hardness were obtained in carburizing process, and cooling process with 30% salt + water cooling medium), the hardness number can increase up to 110% from the initial is 120.08 Kg/mm~2.