Cast iron is a popular structural material in the automotive industry. It is inexpensive. It has good casting properties and workability. But the reduced strength and high fragility of cast iron lead to failure of parts made from it during their operation.
The physical properties, chemical composition and structure of cast iron belongs to limited weldable alloys, due to its low ductility and tendency to bleaching.
To prevent cracking and bleaching, the part should be heated before welding and cooled slowly after welding. This is a very time-consuming process (especially for large parts), therefore it is recommended to use it only if it is impossible to use cold welding.
Technologies for the prevention of cracks in cold welding:
- the use of small diameter electrodes, welding at reduced modes (low current) and random welding;
- reducing the volume of the deposited metal and forging it in a hot state.