Welding Cast Steel with 7018 Rod: A Comprehensive Guide

Many wondered if 7018 rod can be effectively used for welding cast steel. This article aims to clarify the process and provide a step-by-step guide on how to achieve successful welds on cast steel using a 7018 rod.

I recently encountered a situation where I needed to weld on a cast steel M60 tank, initially using a stainless steel rod, which worked well. While steel, often 7018 rod, is a common choice for welding, the key lies in the preparation and technique.

Can You Weld Cast Steel with a 7018 Rod?

Yes, you can weld cast steel with a 7018 rod, but it requires some specific preparation and a proper technique. The 7018 rod is a versatile electrode that works well for various applications, but it is crucial to ensure the cast steel is properly prepared before welding.

Preparation Before Welding

The first step in successfully welding cast steel with a 7018 rod is to prepare the surface. Start by grinding the broken pieces to a razor-sharp edge. This ensures a seamless fit and a strong weld.

Welding Process

Once the pieces are ready, you can proceed with the welding process:

Preheating: Preheat the cast steel to about 200°F (93°C). This step is crucial to reduce the risk of cracking during the weld. Tack Welding: Use a tack weld to hold the pieces together. This step ensures the parts do not move during the welding process. Full Beading: Run a full bead on both the front and back sides of the joint. This creates a strong, continuous weld and reduces the risk of cracks. Relief and Break Test: Allow some time for the weld to cool. A snack or a break here is recommended. Perform a break test to check for any cracks. If cracks are observed, repeat the process until the joint is strong and crack-free. Post-Weld Cooling: To further reduce the risk of cracking, bury the weld in a bucket of sand or surround it with packed sand. This helps in slowing down the cooling process. Cooling and Finishing: Allow the weld to cool naturally. If necessary, grind the weld joint to ensure a smooth finish. However, avoid putting extra heat into the part as this can weaken the weld.

Conclusion

Successfully welding cast steel with a 7018 rod is not impossible. With the right preparation and technique, you can achieve strong and reliable welds. Remember, the key steps include proper preheating, tack welding, full beading, relief, and careful cooling.