Pickling with hydrochloric acid is a standard method to clean steel surfaces before hot-dip galvanizing. When normal low strength steels are pickled, hydrogen formed in pickling reactions does not have any significant harmful effect on the mechanical properties of steel. However, in pickling of steels with higher strength, the penetration of hydrogen into the steel may cause severe damages.e effect of pickling of high-strength low-alloy (HSLA) steels was investigated using a cell construction based on the DevanathanStachurski method with modified anodic surface treatment and hydrogen production using acid. e penetration and the permeability of hydrogen were measured using an electrochemical cell with hydrochloric acid on the one side of the steel sample and a solution of NaOH on the other side. No protective coating, for example, palladium on the anodic side of the sample, is needed. e penetration rate of hydrogen into the steel and exit rate from the steel were lower for higher strength steel.

A spontaneous reaction involving a sparingly soluble solid compound 1,2,4-triazole as sodium salt and a complex substituted aliphatic halide was studied. Kinetic experiments were performed in the temperature interval 120−170 °C. A part of the study was focused on the solubility of different compounds and the impact of triazole concentration on the reaction. On the basis of the experimental data, a mathematical model was developed, and the parameters in the model were estimated by nonlinear regression. On the basis of the consistency of the data, rather accurate values for the parameters were calculated from the experimental values and compared to the estimated ones. The model can be used as a helpful tool in developing industrial applications.

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