Welding wire for Fe—36Ni alloy

Welding wire intended to be used for welding together portions of parts, which portions have the following composition in wt. %:

• 35.0%≤Ni≤37.0%
• trace≤C≤0.10%
• trace≤Mn≤0.60%
• trace≤P≤0.025%
• trace≤S≤0.025%
• trace≤Si≤0.35%
• trace≤Cr≤0.50%
• trace≤Mo≤0.50%
• trace≤Co≤0.50%
• the rest consisting of iron and inevitable impurities resulting from production,
• wherein the welding wire is made in an alloy comprising, in wt. %:
• 38.6%≤Ni+Co≤45.0%
• trace≤Co≤0.50%
• 2.25%≤Ti+Nb≤0.8667×(Ni+Co)−31.20% if 38.6%≤Ni+Co≤40.33%
• 2.25%≤Ti+Nb≤3.75% if 40.33%≤Ni+Co≤41.4%
• 0.4167× (Ni+Co)−15.0%≤Ti+Nb≤3.75% if 41.4%≤Ni+Co≤45.0%
• trace≤Nb≤0.50%
• 0.01%≤Mn≤0.30%
• 0.01%≤Si≤0.25%
• trace≤C≤0.05%
• trace≤Cr≤0.50%
• the rest consisting of iron and inevitable impurities resulting from production.