Improvement of cavitation erosion resistance of AISI 316 stainless steel by laser surface alloying using fine WC powder

K. H. Lo, F. T. Cheng, C. T. Kwok, Hau Chung Man

Research output: Journal article publicationJournal articleAcademic researchpeer-review

82 Citations (Scopus)

Abstract

Fine WC powder of approximately 1 μm size was employed as a convenient source of tungsten and carbon in the laser surface alloying of AISI 316 stainless steel for improving the cavitation erosion resistance. A slurry containing WC powder was preplaced on the substrate by pasting and processed with a high-power CW Nd:YAG laser to achieve surface alloying. The composition and microstructure of the alloyed layer and the phases formed were investigated by energy-dispersive X-ray spectroscopy, optical microscopy, scanning electron microscopy, and X-ray diffractometry, respectively. The cavitation erosion behavior of the laser surface-alloyed samples in 3.5% NaCl solution was studied with a vibratory cavitation erosion tester. The microhardness of the alloyed layer increases with the total W content in the layer. By employing proper processing parameters, an alloyed layer that is hard but not too brittle can be formed, with a cavitation erosion resistance that may reach more than 30 times that of the asreceived 316. The improvement in cavitation erosion resistance may be attributed to the increase of W in solid solution and to the precipitation of dendritic carbides, both resulting from the dissociation of the fine WC powder during laser processing.
Original languageEnglish
Pages (from-to)258-267
Number of pages10
JournalSurface and Coatings Technology
Volume165
Issue number3
DOIs
Publication statusPublished - 17 Feb 2003

Keywords

  • AISI 316 stainless steel
  • Cavitation erosion
  • Laser surface alloying
  • Tungsten carbide

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

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