Abstract
The predictability of hardness of the heat affected zone (HAZ) in aluminum weldments cooled in palm oil, based on hardness of similarly cooled mild steel and cast iron weldments has been ascertained. The general model: α = 1.2769 indicates that HAZ hardness of aluminium weldment is dependant on the ratio of product to sum of HAZ hardness of mild steel and cast iron weldments cooled in palm oil under the same conditions. The maximum deviations of the model-predicted HAZ hardness values α, μ and β from the corresponding experimental values αexp, μexp and βexp were less than 0.04% indicating the reliability and validity of the model.
Highlights
In recent times, great importance has been placed on the weldability of some alloys as a way of repairing structural components damaged in service
The present study aims at ascertaining the predictability of the hardness of the heat affected zone (HAZ) in aluminum weldment cooled in palm oil, as a function of the respective and combined values of HAZ hardness of mild steel and cast iron welded and cooled under the same conditions
Where: α = Model-predicted hardness of HAZ in aluminum; weldment cooled in palm oil (VPN); β = Modelpredicted hardness of HAZ in mild steel; weldment cooled in palm oil (VPN); μ = Model-predicted hardness of HAZ in cast iron weldment cooled in palm oil (VPN)
Summary
Great importance has been placed on the weldability of some alloys as a way of repairing structural components damaged in service. The application of fusion welding and other conventional welding processes in the repair and fabrication of nickel based superalloy such as RR1000 has been seriously restricted This is because these alloys especially those containing significant amount of Al and Ti (>3 wt%), have been considered highly susceptible to heat affected zone (HAZ) cracking during welding and post weld heat treatment strain age cracking [1]. The values of μ and β (from Equations (14) and (15) respectively) evaluated to be approximately equal to the respective corresponding experimental values μexp and βexp confirm the validity of the model This implies that the general model; Equation (13) can predict the HAZ hardness of any of aluminum, mild steel and cast iron weldments cooled in palm oil as a function of the HAZ hardness of the other two materials, providing the three materials constituting the model (aluminum, mild steel and cast iron) were cooled in palm oil. Based on the foregoing, the models in Equations (6), (7) and (13) are valid and very useful for predicting HAZ hardness of aluminum, mild steel and cast iron weldments cooled in palm oil depending on the material of interest and the given HAZ hardness values for the other materials
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
