To obtain a plating structure for a sliding member having characteristics satisfactory not only in terms of corrosion resistance, wear resistance and sliding characteristics but in dimensional accuracy as well.
A piston rod 6 having a sliding section 1 and non-sliding sections (including threaded portions) 3, 4 and 5 is suspended and supported as a subject, to a hanger 14 and is immersed into a plating bath 10 within a conductor case 12. Pulse currents are first supplied from a current rectifier 17 and a first chromium layer having no crack and having excellent corrosion resistance is thinly formed over the entire part of the piston rod 6. Next, a masking tool 23 is risen to mask the non-sliding sections 3, 4 and 5 and in such a state, a DC current is supplied from the current rectifier 17 to form a second chromium layer having the cracks and having the excellent wear resistance and sliding characteristics is thickly formed on the first chromium layer of the sliding section 1, The non-sliding sections 3, 4 and 5 assure the desired dimensional accuracy by the first chromium layer.
KOBAYASHI YUICHI
Toshio Nakamura
Miyazaki Yoshio
Kaoru Onozuka