The in situ-investigation methods of atomic-electronic disordering of surface oxides on metals were developed. The methods are based on the phenomenon of photoelectric polarization of surface oxide, that arising in oxide under illumination by active light unsymmetric modulated in the range of the sound frequences.
The methods allow to establish a nature and concentrations of point defects and impurities dissolved in oxide; to study the kinetics of its formation under electrode potential changing or composition of electrolyte changing.

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Three phenothiazine derivatives in the form of their hydrochlorides are evaluated as inhibitors by Tafel Intercept and Linear Polarization Resistance techniques particularly to establish the applicability of these electrochemical techniques in evaluation of inhibitors. Corrosion of mild steel in hydrogen saturated 0.1N H₂SO₄ is significantly inhibited in the presence of Promethazine, Chlorpromazine and Trifluoperazine salts. The inhibitor efficiency of these new inhibitors is found to be in order of-Trifluoperazine hydrochloride>Chlorpromazine hydrochloride>Promethazine hydrochloride.

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The effect of residual stress and thickness of SUS 304 stainless steel tubes on the SCC were studied in boiling 45% MgCl₂ solution. The SCC test were carried out in a specially designed cell in which cracks propagated from outside to inside of tubes. The main results obtained are as follows.
Tangential residual stresses of metal roll straightened tubes were 2-14kg/mm², and those of rubber roll straightened tubes are 0-6kg/mm². All tubing specimens caused SCC in boiling 45% MgCl₂ solution in a week when the residual stress, δ_t, was higher than 4.5kg/mm². However no crack was observed when δ_t was lower than 2.5kg/mm² in the same condition. The time to cause SCC leak, T_f, increased logarithmically with the decrease of δt and with the increase of tube thickness, t, respectively. These relations can be described by the following experimental equation, logT_f=a-bδ_t/t, whrer T_f: time to cause SCC leak, δ_t: tangential residual stress, t: wall thickness of tube, a, b: constant.

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Inhibition of the corrosions of carbon steel, copper and 70/30 cupro-nickel by various inorganic and organic inhibitors in 12.45mol/l alkaline lithium bromide aqueous solution were investigated in glass sealed tube at 160°C. A mixed inhibitor of lithium hydroxide, sodium tetraborate and benzotriazole (BTA) of 0.145, 0.03 and 0.005mol/l respectively is the most effective on corrosion inhibition for metals.
The infrared spectroscopy and chemical analysis of surface films and polarization measurement of carbon steel suggests that the metal oxide and metal-BTA complex are held on the metal surface and the inhibitory action of this deposit type film inhibits both the cathodic and anodic corrosion processes.

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Electron microprobe has led to a greatly increased knowledge of the relationships between the mechanism of scale formation by high temperature oxidation and sulfidation and its microstructure. But, it is very difficult to analyse acculately constituents of scale with this instrument. This paper reviews guide to find optimum method for oxde- and sulfide scale analysis. Special emphasis is plased on the sample preparation of scale and the operating parameter of electron microprobe for measurement of long wavelength oxygen K_α line.

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