Copper-free solid wire for gas-shielded metal arc welding (GMAW/MAG) of creep-resistant P91 steels, modified with controlled additions of Nb, V, and N to enhance creep resistance and long-term high-temperature stability. The chemical composition is optimized with Ni + Mn < 1 wt.%, allowing post-weld heat treatment (PWHT) at higher temperatures. A relatively high Si content improves weld pool fluidity, favoring root pass execution without backing gas. P91 is widely used for headers, main steam piping, and turbine casings in fossil fuel power plants, including next-generation combined cycle plants. The Bruscato Factor (X-factor) is controlled at < 12 to reduce susceptibility to temper embrittlement during prolonged high-temperature service. For use with Ar + CO₂ or Ar + O₂ shielding gas mixtures.
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