Iranian Journal of Materials Science and Engineering

Abstract:

transition and heat affected zones formed during surface remelting (in order to improve wear resistance) with TIG

process has been investigated. Relationship between various TIG parameters and thickness of remelted and heat

affected zones revealed that a high concentrated heat energy is imposed by TIG process which makes it a proper option

for focused surface treatment. Based on microstructural examinations five areas with different microstructure and

microhardness were identified within the surface area. Graphite flakes were totally dissolved within the first area

leading to the transformation of denderitic austenite to plate martensite and the formation of ledeburite within

interdenderites. The main feature of the second area, resulted from the presence of graphite flakes, was the local

melting with a gap in the vicinity of graphite flakes and that of third area was the formation of finer and denser

martensite plates closer to the graphite flakes compared with those formed at a further distance. In the fourth layer

there is a mixture of martensitic and pearlitic matrix while the matrix of fifth layer has no change of microstructure.