The increasing use of hardfacing alloys in various applications like mining, agriculture, nuclear power plant is leading to come up with new welding techniques such as laser cladding.
Laser cladding is a promising technique to control the dilution level at elevated temperatures. In this study, thermocalc software is used to derive the composition of iron based hardfacing alloy, and nitrogen enrichment is done during the alloying process to increase the concentration of precipitates.
CO2 laser with 1.7 and 2 kW is used to deposit the premixed powders of iron based hardfacing alloy onto SS316 substrate.
Different cladding traverse speeds in the range 18 to 30 mm/s were used for premixed clad powder of Iron based hardfacing alloy. Two powder feeding rates were used, 4 and 35 gm/min to see any change in dilution levels.
The results showed that different percentages of area dilution were found ranging from 1-2% for premixed clad powder depending on the laser cladding independent variables used.
Furthermore, to evaluate the mechanical properties of the weld overlay, micro hardness and high temperature sliding wear is carried out.
This article is shared by R. R. Garbade and N. B. Dhokey of Powder Metallurgy Tribology and Cryo Engg. Group, College of Engineering Pune.