| 摘要 |
PURPOSE:To prevent a steam path portion from corrosion by padding hardening agent on a surface subjected to corrosion and further forming a super hardening layer containing mainly chromium carbide on the surface. CONSTITUTION:18Cr-12Ni steel is used for material of a bypass valve for a main steam stopping valve and stellite material is padded on a valve meet portion to restrain usual oxydization. This stellite material is used also for hardening agent. A chromium carbide layer 12 is deposited on the surface on which the stellite 11 is padded, by Cr pack process to harden the surface. Thus, corrosion due to solid grains spattering from a boiler can be prevented. |
