Welding cast iron to stainless steel can be challenging due to their different metallurgical properties and thermal expansion rates. However, there are a few filler metal options that are commonly used for this type of welding:
Nickel-Based Filler Metal: Nickel-based filler metals, such as ENiFe-CI (AWS A5.15) or ENi-CI (AWS A5.11), are often recommended for welding cast iron to stainless steel. These filler metals have a high nickel content, which helps provide good strength and ductility while accommodating the differences in thermal expansion between the two materials.
Nickel-Steel Electrodes: Certain nickel-steel electrodes, such as ENi-CI (AWS A5.15) or ENiFe-CI (AWS A5.11), can also be suitable for joining cast iron to stainless steel. These electrodes contain a combination of nickel and steel, offering a balance of strength and weldability for this specific application.
When welding cast iron to stainless steel, it is important to consider preheating the cast iron and controlling the heat input during the welding process. Proper preheating and post-weld heat treatment may be necessary to minimize the risk of cracking or distortion.
It's worth noting that welding dissimilar metals, such as cast iron and stainless steel, requires skill and expertise. If you're not experienced in this type of welding, it is advisable to consult with a qualified welder or seek professional assistance to ensure a successful and durable weld.