Metal powder for additive manufacturing

A metal powder having a composition comprising the following elements, expressed in content by weight:

• 6.5%≤Si≤10%
• 4.5%≤Nb≤10%
• 0.2%≤B≤2.0%
• 0.2%≤Cu≤2.0%
• C≤2%
• and optionally containing:
• Ni≤10 wt %,
• Co≤10 wt %,
• Cr≤7 wt %,
• Zr as a substitute for any part of Nb on a one-to-one basis,
• Mo as a substitute for any part of Nb on a one-to-one basis,
• P as a substitute for any part of Si on a one-to-one basis,
• one or more additional elements selected from a group consisting of Hf, Ta, W, V and Y and wherein a content by weight of each additional element is less than 3.5% and/or,
• one or more rare earth metals, wherein a content by weight of each rare earth metal is less than 0.2%,
• a balance being Fe and unavoidable impurities resulting from processing, the metal powder having a microstructure comprising at least 5% in area fraction of an amorphous phase, a microstructure balance being made of crystalline ferritic phases with a grain size below 20 μm and possible precipitates, the metal powder having a mean sphericity SPHT of at least 0.80, at least 20% of grains in the crystalline ferritic phase having a grain size of at least 1 μm.