Which One Is Better For Corrosion Resistance, Galvanized With Spangle Or Zero Spangle?

How are zinc spangles formed on galvanized sheets? Between spangled galvanizing and non-spangled galvanizing, which offers better corrosion resistance?

In fact, a high-purity fresh zinc solution cannot form spangles during cooling because the zinc lacks necessary nucleation sites. Only when specific alloy elements, such as lead or titanium, are added in appropriate amounts to the zinc solution can crystallization occur during the cooling process, forming snowflake or hexagonal zinc spangles. However, these spangles are primarily decorative and serve no practical functional purpose, making them mainly suitable for architectural applications.

Contrary to their visual appeal, spangled galvanizing performs poorly in corrosion resistance. Its uneven surface texture further limits its utility. For this reason, galvanized sheets intended for painting typically use non-spangled or small-spangled coating products, which provide smoother surfaces and superior corrosion protection.

‌Key Points:‌

• ‌Formation Mechanism:‌ Zinc spangles require alloy additives (e.g., Pb, Ti) to create nucleation sites for crystallization.
• ‌Aesthetic vs. Function:‌ Spangles enhance visual appeal but compromise corrosion resistance due to structural irregularities.
• ‌Practical Applications:‌ Non-spangled or small-spangled coatings are preferred for industrial and painted surfaces where durability and smoothness are critical.