Erosion resistant machine component, method for forming surface layer of machine component, and method for manufacturing steam turbine

Patent metadata

Field	Value
Publication number	US-9359682-B2
Application number	US-201514679098-A
Country	US
Kind code	B2
Filing date	Apr 6, 2015
Priority date	Jul 28, 2009
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

A method for forming a surface layer, the purpose thereof is to form a high erosion resistant film. The method for forming a surface layer includes: arranging a member ( 2 ) in a machining fluid ( 3 ); and forming the surface layer including silicon by spacing a silicon electrode ( 1 ) from the member ( 2 ) at a predetermined distance, and by supplying silicon component from the silicon electrode ( 1 ) to the member side by applying a predetermined voltage and generating electric discharge, and an iron-based metal texture including silicon of 3 to 11 wt % is formed at a thickness of 5 to 10 μm at a portion to be treated by repetitively generating a electric discharge pulse in which a time integration value of a current value of the electric discharge pulse is in a range of 30 A·μs to 80 A·μs.

First claim

The invention claimed is:

1. A method for forming a surface layer, the method comprising:
arranging a member in a machining fluid;
spacing a silicon electrode from the member at a predetermined distance; and
forming an iron-based metal layer including silicon on a surface of the member by supplying silicon component from the silicon electrode to the member by applying a predetermined voltage and repetitively generating electric discharge,
wherein a time integration of a current value of the electric discharge pulse is ranged between 30 A·μs and 80 A·μs, and
wherein the iron-based metal layer includes 3 to 11 wt % of silicon and has a thickness of 5 to 10 μm.

2. The method for forming a surface layer according to claim 1 ,
wherein the silicon electrode has a specific resistance of 0.01 Ωcm or lower.

Assignees

• Mitsubishi Electric Corp

Inventors

• Goto Akihiro
• Sumi Nobuyuki
• Nakano Yoshikazu
• Teramoto Hiroyuki

Classifications

• F01D25/285

  Temporary support structures, e.g. for testing, assembling, installing, repairing; Assembly methods using such structures · CPC title

• C23C26/00

  Coating not provided for in groups C23C2/00 - C23C24/00 · CPC title

• F01D5/288

  Protective coatings for blades · CPC title

• Y10T29/49321

  Assembling individual fluid flow interacting members, e.g., blades, vanes, buckets, on rotary support member · CPC title

• F05D2220/31

  in steam turbines · CPC title