Surface microstructure and properties of nodular cast iron rapidly solidified by laser surface melting+1

Reita Murakami, Ichihito Narita, Hirofumi Miyahara

Research output: Contribution to journalArticle

Abstract

Ferrite-matrix nodular cast iron has been modified by a laser surface melting process to develop its microstructure and to improve the surface hardness. A YAG laser beam was irradiated on a substrate and the microstructure of the melted layer was investigated as a function of the pulse energy at a constant specimen travel speed. The surface of the specimen is melted and then rapidly solidified up to a depth of 100 µm order. The melted depth increases with increasing pulse energy. In addition, the ferrite-phase matrix around the spheroidal graphite in cast iron preferentially melts because several alloying elements are segregated at the ferrite/graphite interface. The solidified layer consists of three distinctive parts: first, a martensite phase appears in the vicinity of the melted/unmelted substrate interface, then single-phase austenite crystallized on the martensite phase, and finally a ledeburite-austenite hybrid structure unidirectionally solidified from the substrate towards the surface. A cooling rate from 0.3 to 2.4

Original languageEnglish
Pages (from-to)1465-1470
Number of pages6
JournalMaterials Transactions
Volume59
Issue number9
DOIs
Publication statusPublished - Jan 1 2018

Fingerprint

Nodular iron
casts
Melting
melting
Ferrite
iron
ferrites
microstructure
Microstructure
Graphite
Lasers
austenite
martensite
Martensite
Austenite
lasers
Substrates
graphite
hybrid structures
Alloying elements

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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Surface microstructure and properties of nodular cast iron rapidly solidified by laser surface melting+1. / Murakami, Reita; Narita, Ichihito; Miyahara, Hirofumi.

In: Materials Transactions, Vol. 59, No. 9, 01.01.2018, p. 1465-1470.

Research output: Contribution to journalArticle

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