Seamless basic flux-cored wire for welding of Chromium-Molybdenum alloyed creep resistant steels with an application temperature up to 500°C with Ar-CO2 shielding gas. Features include: excellent weldability in flat and horizontal positions, smooth and bright bead, low spatter losses, easy to remove slag, good mechanical properties and high deposition rates with very low contents of diffusible hydrogen in the weld metal (< 3ml/100g).