The Influence Of The Composition Of Calcium Carbonate And Activated Carbon In The Process Of Pack Carburizing Low Carbon Steel In The Review Of Hardness And Micro Structure

Abstract

Abstract

Carburizing is a way of hardening the surface by heating the metal (steel) above the critical temperature in an environment containing carbon. Steel at a temperature of about the critical temperature affinity to carbon. Carbon is absorbed into the metal form a solid solution of carbon-iron and the outer layer has a high carbon content. When the composition of the activator and the activated charcoal is right, it will perfect the carbon atoms to diffuse into the test material to low carbon steels. Thick layer of carbon depending on the time and temperature are used. Pack carburizing process in this study, using 1 kg of solid carbon derived from coconut shell charcoal with a variation of 20%, 10% and 5% calcium carbonate activator, burner temperature 950 0C, holding time 4 hours. The test material is low carbon steel has 9 pieces. Each composition has three specimen. Furnace used in this study is a pack carburizing furnace which has a designed burner box with a volume of 1000 x 600 x 400 (mm3) of coal-fired.  Equipped with a circulation of oxygen from the blower 2 inches and has a wall of refractory bricks.   From the variation of composition CaCO3, microstructure formed on the specimen with 20% CaCO3, better diffusion of carbon into the carbon steel, it is seen by the form  martensite structur  after guenching, this indicates that there has been an increase or adding carbon to in the specimen.   This led to the formation of martensite specimen into hard surfaces,  where the average value of hardness at one point side (side edge) 31.7 HRC