抄録
Chemical dip polishing action in the newly presented bath of dehydrated phosphoric acid (DPA) added with some organic solvents were investigated.
Appearances (smoothness, pitting and colouring) of the metal surface polished chemically in the above mentioned bath were observed, and the corrosion loss of the polished was also measured, taking the experimental conditions, such as bath composion, temperature and dipping duration, into consideration.
(1) Brightening action for steel was obtained by using the baths composed of 10 parts of DPA (concenterated up to P2O5 78%) and 1-5 parts of such organic ingredients as alcohol, ether, keton, organic acid anhydride and their derivatives.
(2) It was found that these baths had the following characteristics compared with the conventional one which contains inorganic reagents besides DPA:
a) Smoothing action was more effective for steel,
b) The lower optimum temperature was found between 60 and 100°C,
c) Corrosive behavior of steel was so small that the corrosion loss of the material immersed in this bath was reduceded to approximatly one half of that treated in the conventional bath.
(3) Some Organic compounds added to DPA seem to contribute to strengthen the activitiy for steel and to improve the ability of making flexible, porous film available for smoothing action of the bath.
