A kind of nickel-free one-component high corrosion resistance environmental protection black phosphating liquid

Abstract

The invention discloses highly corrosion-resistant environment-friendly black phosphatizing liquid without nickel single component. Each liter of the treatment liquid consists of the following raw materials: 25-50g of main film forming agent, 5-25g of film forming aid, 0.1-3g of accelerant, 60-80g of grain refiner, 0.5-2g of stabilizer, 0.05-1g of blackening agent and 0.1-0.5g of blackening aid. The phosphatizing liquid disclosed by the invention can form a black phosphatized film on a steel surface by a one-step process. The phosphatized film has high blackness and high corrosion resistance, is uniform and avoids stripping; a copper sulfate spot test can reach 40min which is much longer than the national standard (2min); the phosphatizing liquid does not contain toxic and harmful substances such as nickel, nitrite and the like and causes little environmental pollution.

Description

technical field

[0001] The invention mainly relates to the field of surface chemistry, in particular to a nickel-free single-component high-corrosion-resistant and environment-friendly black phosphating solution. Background technique

[0002] Phosphating is a commonly used metal surface treatment technology. In principle, it belongs to chemical conversion film treatment. It is mainly used for phosphating on steel surfaces. Non-ferrous metals (such as aluminum and zinc) can also be phosphating. Phosphating is a process in which chemical and electrochemical reactions form a phosphate chemical conversion film, and the formed phosphate conversion film is called a phosphating film. The purpose of phosphating is mainly to provide protection for the base metal and prevent the metal from being corroded to a certain extent; it is used as a primer before painting to improve the adhesion and anti-corrosion ability of the paint film layer; it can reduce friction in the metal cold proces...