Low chromium anticorrosive chemical conversion treating fluid on surface of constructive aluminium profile and use method thereof

Abstract

The invention discloses a low chromium anticorrosive chemical conversion treating fluid on the surface of constructive aluminium profile and a use method thereof; the technology comprises placing constructive aluminium profile in a tank liquor to treat with a pH value of 1.8-2.2 at 5-40 DEG C for 3-5min or 0.5-1.5min to form a layer of compact and uniform golden to irisated chromate conversion film with a film thickness of 1-2mu m on the surface of the constructive aluminium profile; wherein, the tank liquor comprises 0.6-2.0g / L of chromate, 0.3-0.9g / L of fluorine compound, 0.1-0.6g / L of zincsalt, 0.2-0.8g / L of nitrate, 0.1-0.5g / L of salts from rare earth metals and 0.3-1.0g / L of stabilizer. The invention has simple process and contains no potassium ferricyanide and low chromate; the solution is stable with little sediment; the service cycle is long; the cost of environment pollution and wastewater treatment is low; the treated waste solution can meet the relative discharge standardsand the invention has other advantages of room temperature use, energy saving, low comprehensive cost and the like.

Description

Technical field:

[0001] The invention relates to the technical field of chemical conversion film treatment on the surface of aluminum alloys, in particular to a low-chromium anti-corrosion chemical conversion treatment liquid on the surface of building aluminum profiles and a method for using the same. Background technique:

[0002] Aluminum alloy profiles for construction require high comprehensive performance such as corrosion resistance, weather resistance, wear resistance, good appearance decoration and long service life. Therefore, aluminum profiles are protected by electrostatic powder spraying and fluorocarbon resin paint coating. Before decoration, surface chemical conversion treatment must be carried out to improve the bonding force between the coating and the substrate and meet the high corrosion resistance requirements. At present, chromate conversion treatment is basically used in my country. Some countries in Europe and the United States have introduced chromate-...