Hot ductility of an Fe-10%Ni alloy during penetration of copper
2002 (English)In: Scandinavian journal of metallurgy, ISSN 0371-0459, Vol. 31, no 4, 256-267 p.Article in journal (Refereed) Published
Today's available theories for hot crack formation are based on the fact that hot cracks are formed in the presence of liquid films in the interdendritic areas or at the grain boundaries, which are exposed to tensile stress. Copper is well known to cause hot shortness in steels. In order to study how the liquid embrittles the material, high-temperature tensile tests were performed at two strain rates during the penetration of liquid copper into Fe-10%Ni. The penetration distance was measured in samples that were exposed to strain without fracturing. The ductility (area reduction), strain and ultimate tensile stress were determined. Microprobe analysis was performed on the fractured samples. The transition temperature of ductility was found at 1400-1450degreesC without copper penetration whereas it occurred at 1025-1078degreesC during the penetration of copper, i.e. copper starts to embrittle at a temperature below its melting point. The microprobe measurements showed that the diffusion rate of copper into Fe-10%Ni was enhanced when the lattice was strained. The results are discussed in terms of a new theory concerning vacancy formation and condensation as the dominating mechanism for hot crack formation during solidification.
Place, publisher, year, edition, pages
2002. Vol. 31, no 4, 256-267 p.
copper, diffusion, ductility, embrittlement, hot cracking, iron, nickel, penetration, steels, embrittlement, steels
IdentifiersURN: urn:nbn:se:kth:diva-21955ISI: 000178479800004OAI: oai:DiVA.org:kth-21955DiVA: diva2:340653
QC 201005252010-08-102010-08-10Bibliographically approved