Pulse Plating of Chromium-Molybdenum on Carbon Steel

Optimization of pulse plating parameters to produce a coating with optimum characteristics with respect to properties such as hardness and corrosion resistance, may be both complicated and time consuming due to the vast possibilities of varying pulse parameters such as wave form, duty cycle and frequency, in addition to plating conditions such as applied current density, temperature and bath composition. The present results show, however, that pulse plating is well suited to produce highly corrosion resistant CrMo-coatings with a Mo-content of approximately 1% and a fairly high hardness. For the present conditions, however, the high corrosion resistance is obtained at the expense of hardness and vice versa. Further optimization may show that it is possible to overcome this, and the presently produced coatings have in total very promising properties which should be seriously considered for practical utilization. Such optimization should be carried out on the basis of a systematic investigation into which parameters are most important in determining the coating quality. The present work should be considered as an introductory effort which will be extended. Results are already available on the effect of the Mo-content and the temperature of the plating bath. These will be investigated and reported later.