Manufacturing method of trivalent chromium plated part

Abstract

A manufacturing method of a trivalent chromium plated part in which a trivalent chromium plating film is formed on a sliding part of a device that seals fluid, the method includes: a step of forming the trivalent chromium plating film on a base material or on a base plating firm formed on a base material surface; a step of applying an external force to the trivalent chromium plating firm; and a step of applying a baking treatment to the trivalent chromium plating firm after the external force is applied.

1 . A manufacturing method of a trivalent chromium plated part in which a trivalent chromium plating film is formed on a sliding part of a device that seals fluid, the method comprising:
 a step of forming the trivalent chromium plating film on a base material or on a base plating film formed on a base material surface;   a step of applying an external force to the trivalent chromium plating film; and   a step of applying a baking treatment to the trivalent chromium plating film after the external force is applied.   
     
     
         2 . The manufacturing method of the trivalent chromium plated part according to  claim 1 , further comprising
 a step of performing a surface finishing on the trivalent chromium plating film by a mechanical treatment after the baking treatment.   
     
     
         3 . The manufacturing method of the trivalent chromium plated part according to  claim 1 , wherein
 the external force is applied by cold working.   
     
     
         4 . The manufacturing method of the trivalent chromium plated part according to  claim 1 , wherein
 the trivalent chromium plated part is a cylinder tube or a piston rod of a fluid pressure cylinder, a cylinder tube or a piston rod of a shock absorber, or an outer tube or an inner tube of a front fork.   
     
     
         5 . The manufacturing method of the trivalent chromium plated part according to  claim 1 , wherein
 number of cracks in a surface of the trivalent chromium plating film is increased by the step of applying the external force to the trivalent chromium plating film.