Abstract
A comparative high temperature wear study was conducted between two alloys: laser metal deposited vana-dium-rich (V-rich) high speed steel (HSS) and spun cast carbide enhanced indefinite chilled double poured (CE-ICDP) iron. Laser Metal Deposition (LMD) of V-rich HSS alloy was performed by using a 4.0 kW Nd:YAG laser atthree different laser scan speeds to investigate the effect thereof on the carbide size and morphology, phaseconstitution and mechanical properties (such as micro-hardness and wear resistance) of the laser metal deposits.A comprehensive microstructural characterization of these alloys revealed that the dendritic microstructureof the V-rich HSS alloy consisted of martensitic matrix and VC carbides. Increasing the laser processing speedssignificantly changed the morphologies of VC carbides from square and round to angular and rod-like shapes.The micro-hardness of the V-rich HSS was improved from 760 HV to 835 HV by increasing the laser processingspeed. During high temperature (500 °C) pin-on-disc wear tests, the V-rich HSS showed excellent wear resistancecompared to CE-ICDP iron. It was found that V-rich HSS with square and round shape VC carbides (V-rich10 mm/s) showed the most improved tribological performance with oxidative wear found to be the dominantwear mechanism at this temperature.
Original language | English |
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Pages (from-to) | 115-126 |
Number of pages | 12 |
Journal | Surface and coatings technology |
Volume | 364 |
Early online date | 27 Feb 2019 |
DOIs | |
Publication status | Published - 25 Apr 2019 |
Keywords
- High speed steel
- Laser metal deposition
- Oxidative wear
- Microstructural refinement
- Hot metal forming
- Carbide morphology
- 22/4 OA procedure