Studies on the corrosion behavior of austenitic stainless steels (AISI 304, 304L, 316, 347, 316L, 302 and 430, all of which were solution treated or sensitized) were conducted in flowing water at the temperature of 200°C to 350°C and the flow rate up to 12m/sec.
No appreciable difference was noted among general corrosion rates of AISI 304, 304L and 347, although AISI 316, 316L and 302 showed slightly higher rate than the former tested. The corrosion rate of AISI 430, however was about ten-fold as large. The sensitizing treatment had no effect on general corrosion or selective attack.
Investigation made in the range of 200°C to 350°C showed that alloys of austenite structure indicated a maximum corrosion rate at 250°C and those of ferrite structure at 300°C, while at those two temperatures the effect of flow rate on the corrosion was most remarkable. The mechanism was discussed of the phenomenon in which a maximum corrosion rate was indicated.

View full abstract

Four types of laboratory corrosion tests involving total or intermittant immersion in artificial sea water or tap water were carried out in order to study the effect of alloying elements on sea water corrosion of Cu bearing steel. The alloy compositions of 32 test steels were designed with two levels' orthogonal array L₃₂ (2³¹), 9 variable factors of which were C, Si, Mn. P, Cu, Ni, Cr, Ti and Al contents. Regression analysis was applied to the test results. Mn, Ni, Ti and Al were found to have no effect on the corrosion. C was harmful, while Cr and P, and in some cases Cu and Si, were beneficial. Martensitic structure of 2% Cr steel was preferable to ferrite-pearlitic structure as far as corrosion resistance to intermittent immersion in artificial sea water was concerned. Cr content in matrix seemed to control the corrosion rate.

View full abstract