Weld Pickling Paste
Pickling paste is a chemical agent for removing heat tint and chromium-depleted zones after stainless steel welding. It restores the surface by building up the passivating protective layer.
Physical-Chemical Mechanism of Action
Pickling paste contains acids like sulfuric acid or zinc chloride, which dissolve heat tint and chromium-depleted zones. These chemical reactions remove the damaged surface layer and enable new passivating layer formation.
Metallurgical Relevance & Welding Risks
Without pickling paste, the surface remains depleted after welding and sensitive to corrosion. This can lead to cracks and deformation, especially in humid environments. Correct application of pickling paste prevents these problems and ensures a durable surface finish.
Workshop Practice & Instructions
1. Apply the pickling paste to the welded surface after it has cooled.
2. Let it set for 5-10 minutes until it solidifies.
3. Then use a fine polisher or polishing machine to smooth the surface.
4. Rinse the area with water and dry it off.