Penggunaan Katalis Kalsium Karbonat Pada Karburasi Padat Baja ST 37

In modern era, we find many equipment that uses metal as the main ingredient in its manufacture. The use of metals that have good hardness is very necessary, especially in the engine parts which must always be in contact with other engine parts. One way to increase metal hardness is to add carbon to the metal. The process of adding carbon is by solid carburizing. The use of calcium carbonate catalyst can also be used to accelerate the reaction of the solid carburizing. This study aims to determine the effect of the carburizing process on ST 37 steel either by using a catalyst or without a catalyst to the hardness test. From the results of observations and data collection that has been done, the average hardness value of raw material is 47.9 HRB. For ST 37 steels which are heat treated at 900ºC, normalizing process and quenching process have an average hardness value of 47.5 HRB and 49.05 HRB. As well as ST 37 steel which is carried out by a solid carburizing process using catalysts and without catalyst, each has a hardness rate of 48.6 HRB and 48.2 HRB. From the results above it is known that the cooling time affects the hardness of steel ST 37. The carburizing process can increase the hardness due to the addition of carbon to the steel. Catalysts play a role in increasing the hardness of steel, this is because the catalyst can accelerate the rate of reaction in carburizing