酸液中における銅および銅合金に対するMBTの腐食抑制効果を検討するために, 塩酸, 硫酸, 燐酸溶液中で浸漬腐食試験を行なった。また塩酸, 硫酸中の銅について分極曲線を求めて検討し, 次の結果を得た。
(1) MBTは非酸化性酸液中の溶存酸素による銅および銅合金の腐食を十分に抑制する能力を持つ。しかし塩酸中では硫酸中より高濃度を必要とする。
(2) Fe³⁺が存在しても, 硫酸中では十分に腐食を抑制するが, 塩酸中ではFe³⁺濃度の影響を受けやすく硫酸より効果が悪い。燐酸中では黄銅の腐食は十分に抑制するが銅に対しては塩酸の場合と同じ傾向を示す。
(3) Cu²⁺による腐食に対しても硫酸, 燐酸中では十分に抑制する。
(4) 分極曲線を検討した結果, MBTは陰陽両分極を増大するが十分に抑制する場合には特異な陽分極が認められ, 陽極における抑制が大きな意味を持つと考える。

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The corrosion of iron-chromium alloys containing 0-30% Cr in maleic acid solution was investigated. The results were summerized as follows;
(1) An increase in chromium content had a favorable effect on the diminition of the active current density of the alloys. The similar results had been found in sulfuric acid and concentrated alkaline solution.
(2) The anodic dissolution and the corrosion weight loss became larger, as the concentration increased and temperature rose.
(3) The logarithms of time and initial current density necessary for the onset of passivity of iron showed straight-line relation.
(4) The formation of the order lattice (Fe₃Cr) in the alloys was found to be responsible for a remarkable anodic dissolution.

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The corrosion of austenitic stainless steels and titanium in the aqueous solutions of several amino acid and their salts was investigated. The total immersion tests, the cell voltage-current curve method and the potentiostatic polarization curve method were adopted.
The following experimental results were obtained: The aqueous solutions of acidic amino acids such as glutamic acid or homocysteic acid were comparatively corrosive, while neutral and basic amino acids scarcely; the corrosive behaviors of acid and basic salts of various amino acids bore some resemblance to those of acids and bases which were estimated to be freed from the salts.
It is suggested that amino acids, which form salts with acids or bases, might have some neutralizing action on them, resulting in reduction in the corrosive effects of these salt solutions.

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