No abstract

Most of the welding of cast iron is repair welding. Carbon pickup and resulting cracks are the main concerns when welding CI. The casting process is never perfect, especially when dealing with large components. Instead of scrapping defective castings, they can often be repaired by welding. Naturally, the very high carbon concentration of typical CIs causes difficulties by introducing brittle martensite in the heat-affected zone of weld. It is therefore necessary to preheat to a temperature of 650 °C, followed by slow cooling after welding, to avoid cracking. The welding was carried out with manual shielded metal arc welding using ENiFe-CI filler metal. Shielded metal arc welding process using a nickel electrode was used to join a grey cast iron. The effect of pre heating on the microstructure, hardness, tensile and toughness was studied than the effect of post weld heat treatment (PWHT) on the microstructure, hardness, tensile and toughness was studied after that the same was tested on the preheated and post weld heat treated specimens. After that we concluded that which heat treatment process is suitable for cast iron weld.