Learn why ENiCu-B nickel-copper weld deposits are selected for machinable cast-iron repair and what dilution and cooling can do to hardness.
ENiCu-B is commonly selected when a repaired cast-iron area must be machined. Its nickel-copper deposit is generally more machinable than a carbon-steel deposit on cast iron.
Why Is Machinability Important?
Many repaired components require:
- Drilling
- Tapping
- Milling
- Boring
- Surface grinding
- Restoration of sealing or bearing surfaces
A very hard weld or fusion boundary can damage tools and make dimensional restoration difficult.
What Can Reduce Machinability?
- Excessive cast-iron dilution
- High welding current
- Wide weaving
- Rapid cooling
- Hard carbides near the fusion line
- An unsuitable electrode for the casting
- Multiple repairs over contaminated metal
How Can Welders Improve Results?
Use low, controlled current; short beads; suitable joint preparation; and the thermal method specified for the casting. Additional layers may reduce dilution at the final machined surface.
Is the Entire Repair Equally Machinable?
Not always. The nickel-copper weld deposit may machine well while the heat-affected zone or fusion boundary remains locally hard.
A trial cut or hardness survey may be useful before committing an expensive machining operation.
Dayang Welding supplies ENiCu-B for maintenance applications where machinable deposits are an important requirement.
