Environment-friendly stainless steel pickling agent free of nitrogen and phosphorus elements and application method thereof

Abstract

The invention relates to the technical field of pickling agents, and particularly relates to an environment-friendly stainless steel pickling agent free of nitrogen and phosphorus elements and an application method thereof. The environment-friendly stainless steel pickling agent free of nitrogen and phosphorus elements is prepared from the following components by weight content in each liter of water: 5-60g of sulfuric acid, 5-10g of sulfamic acid, 20-100g of strong oxidant, 50-140g of fluoride, 20-70g of chloride, 3-8g of corrosion inhibitor, 10-20g of ethanol and 1L of water. The environment-friendly stainless steel pickling agent free of nitrogen and phosphorus elements disclosed by the invention is short in cleaning time, and good in cleaning effect, and can be used for cleaning at normal temperature, a cleaned stainless steel welding spot part is bright in color and luster, and the environment-friendly stainless steel pickling agent is convenient to use, and can be recycled, so that the cost is reduced, and pollution to the environment is reduced.

Description

technical field [0001] The invention relates to the technical field of pickling agents, in particular to an environment-friendly pickling agent for stainless steel that does not contain nitrogen and phosphorus elements and an application thereof. Background technique [0002] At present, the development of industrial cleaning technology has made great progress, and has successfully solved many practical problems in production practice. However, traditional stainless steel pickling agents generally use nitric acid or nitrates, phosphoric acid, etc. as pickling oxidants, and these The workpiece pickled by the pickling agent of the formula system not only has the problem that the weld bead is easy to turn white and gray, but also nitric acid, nitrate, and phosphoric acid are likely to cause deterioration of water quality. Nitride has seriously affected the health of operators, so the use of these system formulations has been limited to a certain extent. [0003] Chinese paten...

AI Technical Summary

Problems solved by technology

[0002] At present, the development of industrial cleaning technology has made great progress, and has successfully solved many practical problems in production practice, but the traditional stainless steel pickling agent generally uses nitric acid Or nitrate, phosphoric acid, etc. are used as pickling oxidants, and the workpieces pickled with these pickling agents not only have the problem of easy whitening and graying of the weld bead, but also nitric acid or nitrate, phosphoric acid are likely to cause deterioration of water quality At the same time, nitric acid or nitrate is prone to produce toxic nitrogen compounds during use, which seriously affects the health of operators, so the use of these system formulations is subject to certain restrictions

[0003] Chinese patent 200910147468.2 discloses a pickling corrosion inhibitor for boiler cleaning, its composition and mass percentage are: acid solution 2.0-10.0%, urethane Tropin 0.08-0.25%, xylene thiourea or thiourea 0.04-0.15%, thiocyanate 0.01-0.05%, dodecyl-hexadecyl benzyl chloride or bromide 0.03-0.12%, surfactant 0.05~0.12%, the balance is water; the acid solution adopts the following varieties and contents: hydrochloric acid 3.0~8.0%, citric acid 2.0-5.0%, sulfamic acid 5.0~10.0%, nitric acid 5.0~8.0%, phosphoric acid 8.0~ 10.0%, sulfuric acid 3.0-6.0%; the pickling agent used to clean the boiler will not produce needle-like pitting or expand and deepen the original corrosion spots, but the pickling agent is used to clean the boiler, it needs to be at high temperature (above 45 ℃) On-going and cleaning time up to 2-10 hours