Cobalt-containing phosphating agent, metal part and surface phosphating treatment method thereof

Abstract

The invention relates to a cobalt-containing phosphating agent, a metal part and a surface phosphating treatment method thereof. The phosphating agent is used for metal part surface pretreatment, and comprises the following components in parts by weight, based on 1000 parts: 5-30 parts of phosphoric acid, 3-10 parts of zinc oxide, 0.5-3 parts of a magnesium salt, 0.5-3 parts of an aluminum salt, 0.5-5 parts of cobalt nitrate and the balance of water. A film layer structure formed by the phosphating agent is compact in structure and firm in adhesion force, and a continuously-even and colored phosphating layer is generated on the surface of the metal part for being applied to phosphating treatment before spraying of steel surfaces such as a cold-rolled plate, a hot-rolled plate and angular steel. A phosphating solution is long in service, is free of wastewater, and can be used for phosphating by brushing, immersing, spraying or a combined way thereof. The phosphating agent can be dried or naturally dried in air at a temperature of 10-50 DEG C, saves energy consumption to a great extent, is short in phosphating time, is free of surface adjustment before use, does not need to add a promoter, and is simple and labor-saving in operation.

Description

technical field

[0001] The invention relates to the technical field of metal surface treatment, in particular to a cobalt-containing phosphating agent, a metal piece and a surface phosphating treatment method thereof. Background technique

[0002] In order to improve the surface performance or appearance of the product, the surface of the workpiece is usually treated. For example, the surface treatment process of aluminum, iron and their alloys has penetrated into all walks of life. Moreover, most of the work requires pretreatment before surface treatment, for example, cleaning, decontamination and degreasing, and metal parts for some purposes also need phosphating, passivation and other treatments.

[0003] Phosphating treatment generally uses a phosphating agent to pretreat metal parts to form a film layer on the surface of the metal part for subsequent surface treatment and increase the bonding force and corrosion resistance of the subsequent film. For example, before s...