Influence of dipinaconborates on the corrosion resistance of ST3 steel in synthetic detergent solutions

Abstract

Experimental data on the effect of lithium dipynaconborates (DPKBL), sodium (DPKBN) and potassium (DPKB) on the corrosion resistance of St3 steel in 3 % aqueous solutions of Labomid-203, MS-8 and Temp-100A synthetic detergents have been obtained. By measuring the stationary potentials of steel in solutions of synthetic detergents, the optimal concentration of dipinaconborates was revealed, which is 20 g/l, at which the highest corrosion resistance of steel is achieved. Studies of the corrosion-electrochemical behavior of St3 steel in 3 % aqueous solutions of Labomid-203, MS-8 and Temp-100A detergents showed that in the presence of dipinaconborates, the anode current density, at the same potentials, is much lower, and the passivation region is larger. than in CMC solutions. It was found that the corrosioninhibiting ability of dipinaconborates in CMC solutions increases in the series DPKBL < DPKBN < DPKBK, and potassium dipinaconborate has the greatest anticorrosive property. Dipinaconborates reduce the corrosion rate of steel at a washing solution temperature of 80 °C, the degree of protection is in the range from 71.4 to 90.6 %. And the braking coefficient is from 3.6 to 10.4. By analyzing the obtained experimental data, it was concluded that dipinaconborates increase the corrosion resistance of St3 steel and can be recommended as an anticorrosive additive to synthetic detergents.