PENGARUH MEDIA QUENCHING AIR TERSIRKULASI (CIRCULATED WATER) TERHADAP STRUKTUR MIKRO DAN KEKERASAN PADA BAJA AISI 1045

Abstract

The cooling rate in the heat treatment processes after the austenitization is completely influencing the micro structure and the nature of steel. Quenching is a cooling process which has a high rate of cooling. But quenching that’s used to carried out had an insufficiency, which cause lower cooling rate than it supposes can be, it’s cause by the formation of an unbroken vapor blanket around the hot specimen. But, to get the martensite phase and the maximum hardness, then the cooling rate that is produced on quenching has to be higher, or at least as same as the critical cooling rate of the steel. Cooling rate, for instance, is determined by the type of steel, the dimension and the size of steel, and the condition of quenchant when quenching is carried out. The aim of this experiment is to check the influences of agited quenchant which used, to the micro structure and hardness of AISI 1045 steel. This experiment also results the determination of specimen size, the making of agited quench installation, and the estimation of cooling time that installation could reach.