Quadratic Model for Predicting the Hardness of Heat Affected Zone in Water Cooled Cast Iron Weldment In Relation to Similarly Cooled Aluminum and Mild Steel Weldments

C I Nwoye

doi:10.4236/jmmce.2009.810066

Abstract

Quadratic and linear models have been derived for predicting the heat-affected zone (HAZ) hardness of water cooled cast iron weldment in relation to the combined and respective values of the heat-affected zone hardness of aluminum and mild steel welded and cooled under the same conditions. It was found that the validity of the model is rooted on the fractional expression; γ/3.0749θ + γ/3.0749β + θ/3.0749β = 1. The respective deviations of the model-predicted heataffected zone hardness values of aluminum, cast iron and mild steel from the corresponding experimental values were less than 0.01% which is quite insignificant, indicating reliability of the model.

Highlights

Research reports [1, 2] have shown that there are several processes and methods of arc welding including carbon-arc welding, atomic hydrogen welding, shielded metal arc welding, plasma arc welding, electroslag welding
The present study aims at deriving quadratic and linear models for predicting the hardness of the heat affected zone (HAZ) in cast iron weldment cooled in water, as a function of the respective and combined values of HAZ hardness of aluminum and mild steel welded and cooled under the same conditions
The derived model is equation (17) Where γ = Model-predicted hardness of HAZ in aluminum weldment cooled in water (VPN) β = Model-predicted hardness of HAZ in mild steel weldment cooled in water (VPN) θ = Model-predicted hardness of HAZ in cast iron weldment cooled in water (VPN)

Summary

Introduction

Research reports [1, 2] have shown that there are several processes and methods of arc welding including carbon-arc welding, atomic hydrogen welding, shielded metal arc welding, plasma arc welding, electroslag welding. It has been demonstrated that arc welding involves the process where by the heat generated by the electric arc is maintained in most cases between the electrodes and the work piece [3]. The quantity of heat required for melting the base metal in the vicinity of the arc and the electrode is supplied by the arc. Some of the processes utilize consumable electrodes which serve to strike an arc onto the work pieces, and they melt to provide the weld metal. Welding remains the most important metal joining process. Cf from equation (22) into the models give exactly the corresponding experimental values θexp, γexp, and βexp [8]

Methods

Results

Conclusion