Take you to experience the pickling process of 201 stainless steel plate

In the actual pickling operation of 201 stainless steel plate, it is inevitable to encounter some problems, such as defects on the surface of 201 stainless steel plate due to pickling. If you do not know the causes and solutions of these defects, then next time make the same mistake. The following will introduce these defects and their causes.

The pickling bubbles are caused by the chemical reaction between the acid solution and the exposed 201 stainless steel surface to generate hydrogen gas. The detailed formation mechanism refers to the formation of some hydrogen atoms when the 201 stainless steel plate and the acid react chemically. , it penetrates into the crystal lattice of stainless steel and deforms it. After deformation, hydrogen diffuses into the metal, and part of the hydrogen atoms pass through the 201 stainless steel plate and become molecular.

Escaped from the acid solution, the molecularization of part of the hydrogen atoms is carried out on the boundary of the 'microscopic pores' generated by the lattice deformation, or in the inclusions and pores of the stainless steel. The pressure can reach a large value (tens of MPa), resulting in internal stress that causes hydrogen embrittlement in the 201 stainless steel plate.

This will make the 201 stainless steel plate make a crackling explosion sound when it is cold-rolled, and its appearance is characterized by small blisters in the shape of strips, which appear as black fine cracks after rupture. After rolling, the bubble cracks on the plate surface will extend and expand, thereby reducing the mechanical properties (impact toughness) of the product. The method to avoid the formation of pickling bubbles is to adjust the concentration of the acid solution, control the temperature of the solution during pickling and the flatness of the strip surface.