| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a spark plug which suppresses peeling of a plating layer in a main fitting and is excellent in corrosion resistance. <P>SOLUTION: Such electrolytic cleaning, that a substrate 1a of the main fitting 1 used for the spark plug 100 and electrodes 202a, 202b are immersed in an alkaline solution to permit conduction while the substrate 1a of the main fitting 1 and the electrodes 202a, 202b are separated from each other, is performed for each of a plurality of electrolytic baths 201 in the order. Therein, in the electrolytic cleaning processing, at least two kinds of electrolytic cleaning of anodic electrolytic cleaning, cathodic electrolytic cleaning and PR electrolytic cleaning are performed. By forming the plating layer on the external surface of the main fitting after such a plurality of times of electrolytic cleaning, the adhesiveness between a base and the plating layer can be improved. <P>COPYRIGHT: (C)2013,JPO&INPIT |
