Carbide precipitation in a H21 tool steel during conventional heat treatment was studied. The aim of this work was to study the exact microstructure and for better understanding of carbide formation during double tempering process of the H21 tool steel. The steel was austenised either at 1 100\u00b0C or 1 250\u00b0C for 1 hour, and water quenched. Double tempering was performed at 650, 750 and 800\u00b0C for 1 hour with air cooling in the first and second temper for each austenising temperature. The results showed that the double tempered microstructure consisted of tempered martensite, lower bainite and carbides. The current study confirmed previous findings and contributed to existing knowledge that depending on the tempering temperature, the types of carbide formed during double tempering were M2C, Fe3C, M6C and M23C6 carbides. The present study \u00a0indings add substantially to our understanding of the carbide formation sequence in the H21 tool steel during double tempering. No secondary \u00a0eak hardening was observed, and the highest hardness (505 HV) was obtained after austenising at 1 250\u00b0C and double tempering at 650\u00b0C, which implies that the double tempering of the H21 tool steel should be carried out below 650\u00b0C.<\/p>\n
Dibuat oleh :\u00a0Meilinda Nurbanasari,\u00a0 Panos \u00a0Tsakiropoulos and \u00a0Eric J. Palmiera<\/p>\n
E-mail:\u00a0 meilinda@itenas.ac.id<\/p>\n
Kata Kunci :\u00a0carbides,\u00a0tempered martensite,\u00a0heat treatment,\u00a0electron microscopy<\/p>\n
Keterangan : \u00a0Makalah ini\u00a0 dimuat pada\u00a0ISIJ International, Vol. 54 (2014), No. 7, pp. 1667\u20131676<\/p>\n
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