Clean galvanized part silicate colorful passivating process

Abstract

The invention relates to a clean galvanized part silicate colorful passivating process, which is used for a post treatment process of electro-galvanization and hot galvanization for steel parts. The process comprises the following steps: a steel part is cleaned by water after electro-galvanization and hot galvanization, is immersed in light-emitting solution for light-emitting treatment for 3 to 5 seconds, is taken out and cleaned with water, is immersed in passivation solution and passivated at room temperature for 5 to 30 seconds, is taken out to be cleaned with water and dried. The light-emitting solution comprises 5 to 15mL / L of 65 percent HNO3, and the balance being H2O; the passivation solution comprises the following compositions: 3 to 10g / L of sodium silicate, 1 to 3g / L of boric acid, 20 to 30mL / L of 30 percent H2O2, 3 to 5mL / L of 65 percent HNO3, 3 to 5mL / L of 98 percent H2SO4, 0.1 to 0.5g / L of KMnO4, 1 to 3g / L of NaAc, and the balance being H2O; wherein the pH value of the passivation solution is controlled between 0.5 and 1.0. The galvanized parts after the treatment of the passivation process has colorful appearance and excellent corrosion resistance, the rusting time of a neutral salt spray test on the parts reaches 80 to 120 hours, and the parts are clean and environment friendly.

Description

technical field

[0001] The invention relates to the technical field of surface treatment of iron and steel materials, in particular to a silicate color passivation process for clean galvanized parts. Background technique

[0002] Corrosion and anti-corrosion are related to economic development and people's life safety. Surface engineering technology is the most economical and effective means and method to solve the corrosion and protection of mechanical parts and materials.

[0003] Electro-galvanizing and hot-dip galvanizing are effective ways to improve the corrosion resistance of steel parts, and are currently widely used in many fields such as construction, transportation, machinery, electronics, and aviation. However, in a humid environment, especially in a hot and humid environment, the galvanized layer is prone to corrosion, causing the surface of the coating to form a dark gray or white loose corrosion product - white rust; after a long time, red rust will appear, th...

Images