Study of restoration by welding of austempered ductile iron

STUDY of RESTORATION by WELD NG of AUSTEMPEREDDUCTILE IRONUfuk ÇAKIRMechanical Engineering, M.S. ThesisAustempered ductile cast iron (ADI) has emerged as an important engineering material inrecent years because of its excellent mechanical properties. These include high strength withgood ductility, good wear resistance, fatigue strength and fracture toughness. The objective ofthis investigation is to study the restoration and/or hardfacing by welding of worn-out partsmanufactured from austempered ductile iron. The work may be divided into two sections. Thefirst deals with studying the influence of austempering process on microstructure andmechanical properties of ADI. The second deals with analyzing the welding of melting regionand heat-affected zone microstructures of austempered ductile iron (ADI). Importance ofwelding when the ADI castings need to be produced and repaired; Procedure of the welding;Difference in the mechanical properties of weld metal with ADI base metal; Assessment ofthe phase transformation and characteristics of the microstructure in the weld joint. naddition, process variables such as preheating, filler metarial, heat input and hardfacingprocess were studied.Keywords: Repair welding, Shielded metal arc welding, Ductile iron, Austempered ductileironJURY:1. Prof. Nurullah GÜLTEK N (Supervisor) Date: 14.11.20052. Prof. Dr. Hüseyin SÖNMEZ Page: 1453. Prof. Dr. Adem BAKKALOĞLU