TY - JOUR
T1 - Solidification structure of stellite overlayer formed on spheroidal graphite cast iron by plasma transferred arc process
AU - Chan, W. S.
AU - Lui, T. S.
AU - Chen, L. H.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1994
Y1 - 1994
N2 - The solidification structures of the overlayers of stellite 1, 6 and 21 cobalt base alloys after overlaid on spheroidal graphite cast iron by plasma transferred arc process were studied in this investigation. The results of low overlaying current (I = 60 A) indicated that the stellite 1 overlayer is dendriteless with large amount of M7C3 and M23C6 carbides, which is different from the dendritic structure of the stellite 6 and 21 overlayers. The interdendritic precipitates of the stellite 6 overlayer are M7C3 and M23C6, whereas those of the stellite 21 overlayer are σ phase and very fine M23C6 carbide. An interfacial layer exists between the overlayer and the base material. Dilution of the overlay material by the base material is responsible for the formation of this layer. The overlayers are rich in iron content when the overlaying current is high (I = 100 A). Under this situation, the solidification structure of the stellite 1 overlayer is dendriteless while that of the stellite 6 and 21 is dendritic. Regardless of this microstructure difference, all of the overlayers consist of M7C3 carbide in blocky and colony shape, and M23C6 carbide in fishbone shape. Owing to the dilution effect, the matrix of the overlayers is α-Fe with lamellar M7C3 carbide.
AB - The solidification structures of the overlayers of stellite 1, 6 and 21 cobalt base alloys after overlaid on spheroidal graphite cast iron by plasma transferred arc process were studied in this investigation. The results of low overlaying current (I = 60 A) indicated that the stellite 1 overlayer is dendriteless with large amount of M7C3 and M23C6 carbides, which is different from the dendritic structure of the stellite 6 and 21 overlayers. The interdendritic precipitates of the stellite 6 overlayer are M7C3 and M23C6, whereas those of the stellite 21 overlayer are σ phase and very fine M23C6 carbide. An interfacial layer exists between the overlayer and the base material. Dilution of the overlay material by the base material is responsible for the formation of this layer. The overlayers are rich in iron content when the overlaying current is high (I = 100 A). Under this situation, the solidification structure of the stellite 1 overlayer is dendriteless while that of the stellite 6 and 21 is dendritic. Regardless of this microstructure difference, all of the overlayers consist of M7C3 carbide in blocky and colony shape, and M23C6 carbide in fishbone shape. Owing to the dilution effect, the matrix of the overlayers is α-Fe with lamellar M7C3 carbide.
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U2 - 10.2320/matertrans1989.35.529
DO - 10.2320/matertrans1989.35.529
M3 - Article
AN - SCOPUS:0028481299
SN - 0916-1821
VL - 35
SP - 529
EP - 537
JO - materials transactions, jim
JF - materials transactions, jim
IS - 8
ER -