"INFLUENCE OF WELDING PARAMETERS ON CHROMIUM CARBIDE HARDFACING BY OPEN ARC WELDING"

Abstract

Hardfacing is one of the method of depositing a specific alloy on the parent metal to impart the desired properties on the component surface. Beads have been deposited with a flux cored self shielded wire of 2.8 mm diameter (Messer-Grieshem make). The welding parameters such as current, voltage and speed have been varied to study their influence on dilution with base metal, deposition efficiency, bead shape, chemical composition of weld deposit and hardness of weld bead etc. The investigations have revealed that dilution increases with the increase in welding voltage and speed, while decreases-;.. with the increase in welding current.Deposition efficiency generally increases with increase in welding parameters, however further increase in the values of welding parameters, lead to reduction of the efficiency.The bead shape coefficients increases with welding voltage and current but decreases with increase in speed.The chromium, Mn and carbon contents in the deposited layer,decreases with increase in arc voltage 'and increase with the increase in the current. No significant influence of welding..-speed is observed on alloy contents. The hardness decreases with the increase in the percentage dilution of the deposited layer. Fine cracks have been observed in most of the beads due to lower plasticity of the chromium carbide alloy. Porosity has been observed in few cases, where the beads were deposited with.a combination of high voltage,