PENGARUH MEDIA PENDINGINAN TERHADAP STRUKTUR MIKRO DAN SIFAT MEKANIK SETELAH PEMANASAN 850°C PADA BAJA STAINLESS STEEL 420

Abstrak

ABSTRACT At most Steel is weared upon which industry where some, determined by its economy value, but top-drawer because which vary characteristic of-in character. In its use it is important to know excess and strongness owned by steel in order to in accordance with its function and usefulness. To get desired characteristics from steel referred as, then needed structure that fit in with chemical composition and heat treatment correct.Testing will use steel type stailess steel 420, that test consist of elementary significant its and significant in common but accept heat treatment as high as 850°C holding time 1 hour with refrigeration media that different each other (water and air). Matter taken is chemical composition test, micro structure test, heat treatment, mechanical characteristic test of (violence Vickers) last micro structure test again. Its target to see mechanical denaturing and micro structure from process referred as.Testing Result is got from a result that is influence heat treatment with refrigeration that different each other (water and air), then violence value with water refrigeration that is 210 HVs and violence value with air refrigeration that is 183 HVs. Analysis of test data result metallografi from two sampels in common, then before the happening of heat treatment this significant is categorized within class type martensite S 420, there will be ferrite elementary body and pearlite that seen at picture, last after significant is given heat treatment with air refrigeration. Significant experiences of change that is elementary body the return austenit (?), whereas micro refrigeration of structure water even also experiences of change from elementary sampel and difference at sampel air refrigeration although still existence of elementary body austenit and ferrite. Difference that resulted can be seen its the truth from violence test on the two sampel and violence value at sampel water refrigeration higher than value of air refrigeration violence.   Keyword: Holding Time, Micro Stuktur, Vickers, Heat Treatment, Ferrite, Pearlite, Martensite, Austenit, Metallografi.