Pickling is an important metal surface treatment process that can remove the oxide scale on the metal surface and improve the glossiness and corrosion resistance.

 

Pickling of Stainless Steel Sofa Legs

The pickling process for stainless steel sofa legs involves treating the legs with pickling solutions to remove surface oxides and impurities such as welding slag. This process is a crucial step in the production of stainless steel sofa legs.

 

After the production of elbows, tees, reducers, caps, flanges, and other components, an acidic solution is used to remove the oxide scale and rust from the surface of the steel. The iron oxides such as Fe3O4 and Fe2O3 react chemically with the acid solution to form salts that dissolve in the acid and are thus removed.

 

Acid used for pickling includes sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, and mixed acids. The most commonly used are sulfuric acid and hydrochloric acid. The main pickling methods are immersion pickling and spray pickling. Immersion pickling is generally used, while spray pickling can be used for small batch production. Steel parts are typically pickled in a 10% to 20% (by volume) sulfuric acid solution at a temperature of 40°C. When the iron content in the solution exceeds 80g/L and ferrous sulfate exceeds 215g/L, the pickling solution should be replaced. After pickling, the metal surface turns silver and is passivated, enhancing the corrosion resistance of stainless steel.

 

The Role of Stainless Steel Passivation Solution:

Stainless steel sofa legs can develop rust, weld spots, oil stains, and black and yellow oxide scales during processes like forming, assembly, and welding. Soaking or spraying with a passivation solution can effectively address this issue, presenting a uniform and attractive silver-white surface on the stainless steel parts while also providing comprehensive passivation. This passivation film is dense, aesthetically pleasing, and has excellent corrosion resistance.

 

During factory production operations, various issues can arise in the pickling process of metal accessories, which can not only affect the pickling effect but also lead to equipment damage and safety hazards.

1. Equipment Failure

Equipment failure is one of the common problems in the pickling process, which may include aging equipment, unreasonable design, etc.

 

- Aging equipment: Equipment used for a long time can easily have mechanical wear, air leaks, blockages, and other issues. These problems can lead to unstable pickling pressure, affecting the pickling effect. To prevent such issues, regularly maintain and service the equipment, and promptly replace aging parts to reduce equipment failures.

 

- Unreasonable equipment design: If the air intake is too small or the air pressure pipeline is slender and has many bends, it will affect the stability of the pickling pressure. If the equipment structure cannot be changed, improve the stability of the pickling pressure by appropriately increasing the air intake area and optimizing the pipeline layout.

 

2. Operational Errors

Operational errors are an important cause of pickling problems, which may involve the preparation, use, and management of the pickling solution.

 

- Inconsistent pickling solution concentration: Improper acid preparation or not adjusting the acid concentration in time during production can lead to uneven pickling effects. To avoid this, strictly follow the acid formula and production process requirements to ensure the stability of the acid concentration.

 

- Unstable pickling process: Non-standard operations can lead to the inability to strictly control pickling process parameters such as temperature, time, and acid concentration. Therefore, operators should strictly follow the pickling process requirements, monitor and adjust the process parameters to ensure the stability of the pickling process.

 

3. Other Common Issues in the Pickling Process

 

- Uneven pickling: Uneven distribution or poor flow of the pickling solution can lead to uneven pickling of the metal surface of the sofa legs. To solve this problem, ensure even distribution and good flow of the pickling solution.

 

- Excessive corrosion: High acid concentration, high temperature, or prolonged washing time in the pickling solution can lead to excessive corrosion of the metal surface of the sofa legs. Therefore, strictly control these parameters to avoid excessive corrosion.

 

- Residual pollutants: Incomplete cleaning of the metal surface after pickling may leave behind acidic or alkaline substances. To ensure cleaning effectiveness, use appropriate cleaning methods to thoroughly remove residues.

 

The acidic solution used in the pickling process poses potential hazards to operators and the environment. Therefore, it is essential to strictly control the operating conditions and working environment of the pickling process to ensure the safety of operators and environmental protection.

 

In summary, there are various issues that may arise during the pickling process, involving equipment, operations, raw materials, and other aspects. To ensure the pickling effect and quality, operators should strictly follow operating procedures, regularly maintain equipment, and strictly control process parameters. Only in this way can the problems encountered in the pickling process be effectively resolved, ensuring the surface quality of the products and production safety.