Steel is a metal that is easily oxidized and corroded, and its surface is generally oxidized and rusted.The common oxides of iron and steel are ferrous oxide, iron oxide, iron oxide, iron oxide and trioxide.Prior to hot dip galvanizing, the rust of the steel surface should be removed, otherwise the plating effect will be affected and even the leakage will be produced.Send InquiryChat Now
Steel is a metal that is easily oxidized and corroded, and its surface is generally oxidized and rusted.The common oxides of iron and steel are ferrous oxide, iron oxide, iron oxide, iron oxide and trioxide.Prior to hot dip galvanizing, the rust of the steel surface should be removed, otherwise the plating effect will be affected and even the leakage will be produced.
Acid cleaning principle of pickling line:
Steel surface rust due to atmospheric corrosion, usually in ferrous hydroxide with iron hydroxide, due to high temperature oxidation of skin, are mainly ferroferric oxide, ferric oxide, iron oxide are easy to be dissolved with acid.In hydrochloric acid, for example the reaction is as follows: ferroferric oxide and ferric oxide in the sulfuric acid and hydrochloric acid solution at room temperature are more difficult to dissolve, but when there is with iron at the same time, corrosion of electrodes, iron as anode, in the process of pickling line pickling and iron oxide skin contact first dissolve, and generate hydrogen gas, prompting oxide skin fall off from the steel surface.At the same time, the hydrogenation of ferric oxide, trioxide and iron oxide are reduced to iron oxide and dissolved in reaction.
In pickling line of pickling line, hydrogen is precipitated in the process of pickling, which has an adverse effect on steel.Because hydrogen is easily diffused into the metal, it causes hydrogen embrittlement, which leads to the ductile, ductility and plasticity of the metal.In order to overcome these defects, it is often improved by adding corrosion inhibitor, wetting agent and fogging agent in the acid cleaning solution of pickling line.
Acid cleaning methods commonly used in pickling line:
Hydrochloric acid is one of the most widely used pickling raw materials in pickling line.The current market is usually 30-32 per cent, equivalent to 345-372 g /LHCL.In a configuration method of Laos in pickling, hydrochloric acid after approach used directly, with the increase of iron content in acid pickling line is more and more slow, at this time in the old acid to add new hydrochloric acid to increase the service life of acid, water now most manufacturers in hydrochloric acid for 15-20% of proportion, so start pickling speed slightly slower.As the iron content increases faster and faster.