酸洗浄時における銅合金の腐食について

抄録

During the acid cleaning of various equipments, one of the troubles frequently encountered is acid attack on construction materials. Therefore, care should be taken to protect the equipment from acid attack during acid cleaning.
Although the acid attack on steel has been studied for many years, there seems to be very little study concerning the acid attack on copper alloys, because the corrosion rates of copper alloys are considered to be comparatively low in the non-oxidizing acid solutions such as hydrochloric acid.
However, the acid solution containing oxidizing agents such as oxygen, ferric or cupric ion, etc. may cause attack.
In this study, we have investigated the effects of acid concentration, temperature, gas atmosphere and oxidizing ions such as ferric or cupric ion on the corrosion of copper alloys in hydrochloric acid solutions.
As a result, it has been found that in the presence of oxidizing ions, the inhibition effect of inhibitors is markedly decreased, and the corrosion rates of copper alloys are greatly accelerated in the inhibited hydrochloric acid solution.
The tendency is more remarkable when air is bubbled through the solution.
On the hand, in the absence of oxidizing ions, the corrosion of copper alloys in hydrochloric acid can be prevented by inhibitors even when air is bubbled through the solution.