Effect of preheat on the welding of gray cast iron

Shielded metal arc welding is a kind of fusion welding process used to join gray cast iron. In this investigation the effect of preheat on the microstructure and mechanical properties of gray cast iron was studied. Preheat included three steps: heating up to 066 °C, applying joint process and then furnace cooling. Optical microscopy was used for the characterization of the microstructure and worn surface of the deposits. Before preheat on the workpiece, heat affected zone exhibited martensitic structure and partially fusion zone exhibited white cast iron structure plus martensite. Applied preheat resulted the dissolution of martensite and graphitization. The results showed by applying preheat in Shielded metal arc welding cause decreasing hardness and yield strength of specimens

کلیدواژه ها:

gray cast iron ، arc welding ، preheat