Abstract
Abstract Laser hardfacing were produced using a high power Disk laser of 4 kW maximum power as a heat source to melt and bond the Colmonoy-5 powder on to AISI 316 LN stainless steel substrate. Significant difference in melting points between the austenitic stainless steel (ASS) substrate and Ni-based Colmonoy alloy results in substantial dilution of the hardfaced deposit from the substrate. In this present study, the effect of travel speed (TS) on microstructure, microhardness and wear characteristics laser hardfaced deposits were investigated. The phase constitution, microstructure and hardness of laser hardfaced deposits were examined by optical microscope, scanning electron microscope, energy dispersion spectroscopy, x-ray diffraction and Vickers hardness tester. The TS was varied between 300 and 500 mm/min. The other parameters such as, laser power, powder feed rate, and defocusing distance were kept constant. From this investigation, it is found that the deposit hardness increased from 750 HV to 800 HV with decreasing in TS. The TS increases, bead height decreased and dilution and depth of penetration increased. Due to higher TS the faster cooling rate takes place, it causes the cracking and porosity. Microhardness and wear resistance are slightly improved in the TS of 400 mm/min. The microstructures of deposit layer are composed of Ni-rich carbide, boride and silicide, this are the responsible for higher hardness and better wear resistance.
Highlights
Austenitic stainless steel (ASS, 316 LN) is the major construction material for prototype fast breeder reactor (PFBR)
When the travel speed (TS) is 300 mm/min, coarse dendrites are observed in the deposit layer
The specimen used for friction and wear tests were made by single-pass laser hardfaced deposits
Summary
Austenitic stainless steel (ASS, 316 LN) is the major construction material for prototype fast breeder reactor (PFBR). The effect of travel speed (TS) on microstructure, microhardness and wear characteristics laser hardfaced deposits were investigated. Zhang et al reported that effect of processes parameter on bead height, bead width, penetration depth and dilution of laser hardfaced Colmonoy 6 deposits are analyzed. On the other hand, hardfacing at higher TSs increases the risk of forming defects, e.g. crack and porosity, in the deposited layers [20, 21].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
