Phosphorization liquid for zinc or zinc-aluminium alloy

Abstract

The invention discloses a phosphating solution for zinc or allumen, belonging to the metal surface treatment technique. The phosphating solution comprises the following raw materials in percentage by weight: 0.1-0.5 percent of zinc oxide, 0.2-0.5 percent of nitric acid, 3-4 percent of phosphoric acid, 0.02-0.04 percent of nickel nitrate, 0.02-0.2 percent of sodium fluoride, and the balance being water. The phosphating solution is made by stirring the raw materials are stirred until solid substance is completely dissolved and then filtering the raw materials. The product is used at normal temperature, and has the free acidity between 1 and 4 points, the total acidity between 25 and 35 points and the phosphating time between 2 and 8 minutes; a phosphating film is uniform, dense, solid and strong in the binding force with a coating; the adhesive force of the coating is over Grade 1; in addition, excessive AL<3+> dissolved in phosphating process can be complexed by F<-> in a bath solution in time, so as to guarantee the normal proceeding of phosphating treatment. The invention has the advantages that: the phosphating solution is good in phosphating effect, low in processing cost, easy to have the process operated and regulated; a spray product treated with the phosphating solution is excellent in the adhesive force of coating and has good corrosion resistance as well as durability.

Description

A kind of phosphating solution for zinc or zinc aluminum alloy technical field The invention relates to a phosphating solution used for phosphating treatment on the surface of metal zinc or zinc-aluminum alloy, belonging to the technical field of metal surface treatment. Background technique Due to the continuous acceleration of the world's industrialization process, the continuous development of the world economy, the intensification of various industrial pollution emissions, the harsh environment and climate, serious air pollution, and accelerated corrosion of steel, the service life of various steel and metal products is difficult to meet people's urgent needs. Taking advantage of the anodic protection of zinc, people carry out various galvanizing processes to enhance the corrosion resistance of steel materials, such as electro-galvanizing, and more hot-dip galvanizing treatments, which significantly improve the corrosion resistance of steel and metal products. The zinc...

AI Technical Summary

Problems solved by technology

The phosphating solutions currently used, such as iron-based phosphating solutions, zinc-based phosphating solutions or manganese-based phosphating solutions, are difficult to achieve good results, and it is easy to cause poor coating adhesion and lack of corrosion resistance, which cannot guarantee the long-term use of materials.

Chinese patents CN1076225, CN1077757, CN1231705, CN1259451, etc. are all phosphating solutions for iron and steel. Chinese patent CN1205356 discusses how to do a good job of phosphating treatment process for aluminum-containing galvanized layer, but does not provide effective phosphating solution products