Welded pipes, particularly those made from 304 stainless steel, often exhibit orange, blue, or black weld spots after welding. These spots are challenging to remove and can negatively impact the pipe’s appearance, accelerate atmospheric corrosion, and reduce corrosion resistance, ultimately affecting its performance. Here are four effective methods to remove weld spots and improve the quality of 304 stainless steel pipes.
1. Stainless Steel Weld Spot Cleaner
• Procedure:
• Soak the welded pipes in a stainless steel weld spot cleaner for 5–20 minutes.
• This cleaner efficiently removes weld spots, oxide scales, rust, and other impurities from the pipe surface.
• Advantages:
• Simple operation requiring no additional equipment.
• Suitable for cleaning large batches, complex shapes, or small components.
• Delivers high cleaning efficiency.
• Result:
• Leaves the surface of the pipe with a uniform matte white finish.
2. Steel Washing Solution
• Procedure:
• Soak the pipes in steel washing solution at room temperature for 10–30 minutes or longer, depending on the workpiece.
• Once surface dirt is removed and a uniform silver-white finish is visible, a dense passivation film is considered to have formed.
• Rinse the pipe with clean water, and for enhanced results, apply a neutralizing anti-rust liquid (e.g., PV-D21).
• Advantages:
• Combines pickling and passivation for enhanced corrosion resistance.
• Suitable for cleaning pipes with strict anti-corrosion requirements.
• Performance:
• Treated pipes can pass the Japanese Industrial Standard Salt Spray Test, demonstrating over 500 hours of corrosion resistance.
• Result:
• Produces a completely uniform silver-white surface.
3. Pickling Passivation Paste
• Procedure:
• Evenly apply pickling passivation paste to the weld spots.
• Leave for 5–20 minutes, then rinse thoroughly with clean water.
• Advantages:
• Achieves the same cleaning and corrosion resistance effects as pickling passivation liquid.
• Ideal for cleaning surface welds on large or irregularly shaped pipes.
• Result:
• Effectively removes weld spots and leaves the surface clean and uniform.
4. Weld Cleaning Machine
• Procedure:
• Use a weld cleaning machine suitable for different pipe finishes, such as matte, brushed, or bright surfaces.
• The machine works by initiating a chemical reaction between the ions in the electrolyte and the oxide scale on the weld spot.
• Advantages:
• Ideal for pipes with medium to high cleaning requirements.
• Effective for irregular workpieces and pipes of various sizes.
• Result:
• Achieves both cleaning and polishing, ensuring a high-quality finish.
Benefits of These Methods
• Enhances the appearance and corrosion resistance of 304 stainless steel pipes.
• Removes impurities that can accelerate corrosion and reduce durability.
• Provides options for different pipe sizes, shapes, and finishing requirements.
By selecting the appropriate method, you can efficiently remove weld spots, ensuring the longevity and performance of 304 stainless steel pipes.
United Steel Industry As the most important steel pipe manufacturer and exporter in China, in the past 20 years, we have completed more than 100 projects, with partners in more than 100 countries, and established relationships with oil and gas and EPC companies in many countries business relationship.
For more information about the product price, catalog and rolling mill inspection certificate,
please consult:Email:Sales@usisteels.com
