PENGARUH PERENDAMAN CYROGENIC TERHADAP SIFAT KEKERASAN DAN STRUKTUR MIKRO PADA FCD-45

Abstract

FCD-45 nodular cast iron is a type of cast iron. to improve the mechanical properties of FCD-45 iron can be done through a direct cooling process. In direct cooling of liquid nitrogen -1930C it can be seen the effect on the increase in hardness properties and changes in microstructure (ferrite, pearlite, graphite). The process of direct cooling of liquid nitrogen -1930C which was carried out included cyrogenic immersion for 72 hours and 120 hours (holding time). The results showed that the effect of direct cooling increased the hardness of the specimen and gave changes to ferrite, pearlite and graphite on the FCD-45 iron microstructure. an increase of 6.83 HRB for a holding time of 120 hours. For the FCD-45 microstructure, it underwent a change where there was addition of ferrite, pearlite and graphite and it was more evenly distributed than the As-cast specimen.