Passivation solution for blades of steam turbine

Abstract

The invention discloses a passivation solution for blades of a steam turbine. The passivation solution comprises the following components in percentage by weight: 10-14% of oxalic acid, 13-17% of tartaric acid, 2.5-3.5% of zinc nitrate, 3-5% of sodium bicarbonate, 3-5% of Mannich base, 2-4% of quinoline quaternary amine salt, 1-2% of urotropine, 0.5-1.5% of thiourea and the balance of water. The passivation solution contains no dichromate and nitrite and the original luster of parts are protected from being damaged after the parts are passivated by virtue of the passivation solution and the parts have excellent corrosion resistance.

Description

technical field [0001] The invention relates to the technical field of surface treatment, in particular to a passivation solution for steam turbine blades. Background technique [0002] Steam turbine blades are mainly made of martensitic stainless steel. This type of steel has low corrosion resistance due to its high hardenability and high carbon content. Therefore, the workpiece after machining must be treated with anti-rust treatment to effectively prevent Rust, there are generally two anti-rust methods commonly used now: one is the traditional method of applying anti-rust oil to physically seal the surface of the parts, and using the oil film to isolate the metal from the oxygen in the air to achieve anti-corrosion effects. Both have good rust resistance. But the defect of its existence is: usually can feel its existence with vision and hand. It is impossible to completely maintain the appearance and dimensional accuracy of the parts, and we know that most anti-rust oil...

AI Technical Summary

Problems solved by technology

But its defect is that it can usually be felt with eyes and hands

Due to the high environmental pollution and high energy consumption of high-temperature operation, although the corrosion resistance of the treated parts has been improved, the polished color of the stainless steel surface is greatly reduced, and it is even very easy to change color. The process is not easy to master

[0004] Based on the above situation, although there has been some research on the passivation of martensitic stainless steel so far, there is still no passivation solution that is environmentally friendly, has strong corrosion resistance, and can protect the luster of parts from being damaged. Martensitic stainless steels, especially the passivation needs of steam turbine blades