Influence of the Electrolyte and Alloy Composition on the Pitting Behavior of Stainless Steel Alloys

Abstract

The influence of Mo, V, W in ferrochrome alloys and of SO4 , C104, Clin an aqueous electrolyte was investigated electrochemically. The effect of minor alloying elements was most pronounced in the active potential region, prior to passivation; Mo, V reduced pitting while W enhanced it. CIpromoted pitting whereas SO4 and CI04 were inhibitors. Removal of surface sulfate ions destroyed this inhibitive effect. Relationships were developed between Epjn Em,,, i,P and [anion] which enabled the prediction of [S0] and (CI -J required to inhibit and induce pitting respectively.

Corrosion Resistance of Some Stainless Steels in Chloride Solutions

“…3). The behaviour of 316 and the 324 steel in chloride solutions is in agreement with previous works by other authors [ 2,9,10]. Only S326 steel (containing 5.5% of silicon), as it was mentioned before, exhibits a high corrosion resistance (also pitting), in all the examined media.…”

Pitting Corrosion Inhibition of Some Copper Alloys in Neutral Solutions by Straight Chain Carboxylates

“…From the plots of this figure it is evident that the value of b 2 increases gradually from (1-5) and then abruptly rises and remains high up to compound (10). After this the value of b 2 greatly decreases for compounds (11)(12)(13). From the plots of Fig.…”

“…In this case, it can be concluded that these low concentrations of chloride are not sufficient to destroy completely the passivating film formed on the metallic surface. Also, the pits formed are not completely active and may undergo repassivation [3][4][5][6][7][8][9][10][11][12][13][14][15]. At higher concentrations of chloride ions the pits formed are assumed to be of the limiting active type.…”

“…The different values of E pit for the alloys I and II in different NaCl solutions are listed in Table 1. Most investigation carried out on the pitting corrosion revealed a straight line relationship between E pit and log C Cl -in a form like [11][12][13]:…”

Electrochemical studies of pitting corrosion of Cu–Fe alloy in sodium chloride solutions

“…(3), the values of E pit are deduced for the different NaCl concentrations and listed in Table (2). The previous studies carried out on the pitting corrosion in NaCl media reveal that there is a straight line relationship between E pit and log − Cl C in the following form [8][9][10] E pit = a 1 …”