MODULARIZATION OF WEB-BASED COLLABORATION SYSTEMS FOR MANUFACTURING INNOVATION

Treating objects of which at least the surface consists of tin in order to obtain a satisfactory corrosion resistance. To this end the objects are subjected in a tungstate solution of at least 0.02 M and having a pH of 4-11 alternately to a cathodic and an anodic polarity (so-called periodically reversed current). The frequency with which the current reverses must be between 0.2 and 2 Hz and the current density must be between 0.2 and 1 A/dm2, the ratio of the anodic to the cathodic density being from 0.5-1.