EFFECT OF PICKLING ON THE MECHANICAL PROPERTIES OF STEEL.

Abstract

In the ease, when steel is pickled in the solution of hydrochloric or sulphuric acid to remove the scale, the mechanical properties of steel are changed at the same time. This fact is known as "Acid Brittleness", and is recognized to be caused by the diffusion of nascent hydrogen, which -is generated during the pickling, into the interior of steel.
The author observed the change of tensile strength and elongation of low carbon steel tubes, small in diameter. which were pickled in acid solutions different in concentration and temperature, The ascertained results of the experiments are as follows:-
1) Steels which are pickled in acid solution show increased tensile strength and decreased elongation.
2) To prevent the acid brittleness of pickled steel, the use of some inhibitor is much effective.
3) Acid brittleness is recovered by means of heating the pickled steel at low temperature or Setting at room temperature for several days.