PENGARUH PERBEDAAN UKURAN BUTIR ARANG TEMPURUNG KELAPA-BARIUM KARBONAT TERHADAP PENINGKATAN KEKERASAN PERMUKAAN MATERIAL BAJA ST 37 DENGAN PROSES PACK CARBURIZING

Abstract

Additional carbon into the structure of low carbon steel commonly defined carburizing, is method to improve hardness and strength. In this way charcoal is employer as a source of carbon. Coconut shell charcoal pulverized into powder with different sizes. The use of different charcoal particle size in carburizing has been done by previous researchers. However, the particle of grain size coconut shell charcoal 0.09, 0.15, 0.212 and 0.3 mm have not used before. In this research, using particle size coconut shell charcoal as described above, mixed with barium carbonate as a chiral activator to form CO2 . Gas this will produce C atoms and 2 CO. C atoms derived from coconut shell charcoal for gas for heating temperature increases. Changes form solids into gas as a function of in temperature, also influenced by the size of its surface area. Coconut shell charcoal with a smaller grain size will be the gas faster than larger ones. Gasify speeds differentiated by differences in grain size of the charcoal, researched effect on surface hardness of specimens produced. Specimens using raw materials of steel St 37, which were included in the group of low carbon steel. This experiment uses temperatures of 900° C and heating time for two hours. The assessment results we concluded that no significant effect was found between grain size coconut shell charcoal with a surface hardness of steel St 37 produced. But the use of coconut shell charcoal with a grain size of 0.15 mm, obtained surface hardness of the highest prices among others. Keywords: Steel St 37, pack carburizing, different grain