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1.4905

X11CrMoWVNb9-1-1

The 1.4905 (X11CrMoWVNb9-1-1 (P911)) is a martensitic 9-%-[[element:Cr|chromium]] steel (P91/P92): extremely [[glossary:kriechen-warmfeste-staehle|creep]]-resistant up to over 600 °C for modern power plants. When welding, it's ruthless — hard and [[element:H2|hydrogen]]-sensitive. Typical analysis: 0.11 % C, 0.2 % V, 0.9–1.1 % W, 9 % Cr, 0.45 % Mn, 1 % Mo, 0.6 % Ni, 0.3 % Si. For higher [[glossary:verschleissschutz|wear protection]], three hard-facing options are available: S Fe 1 (martensitic, approx. 300–400 HB, machinable), S Fe 2 (wear-resistant and tough, approx. 50–55 HRC, conditionally machinable) and S Fe 15 ([[glossary:karbid|carbide]]-rich, approx. 55–65+ HRC, not machinable).

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