1. The effect of too high zinc liquid temperature or too long zinc dipping time on the rough surface of the angle steel galvanized layer. The hot-dip galvanized angle steel will also appear rough due to slow cooling after being taken out of the zinc liquid, or the steel section is too thick, or the angle steel is stacked immediately without isolation after hot-dip galvanizing.

2. "Over-pickling" occurs during the pre-plating process, making the steel surface rough or producing bean marks, which is also one of the reasons for the rough surface of the workpiece after hot-dip galvanizing.

3. The surface of the steel used for hot-dip galvanized angle steel is originally rough and uneven, with rust pits or obvious rolling stripes. After hot-dip galvanizing, its surface is generally not as flat and smooth as before.

4. When the welder strikes the arc on the metal surface, the surface of the hot-dip galvanized angle steel will show rough defects, which will damage the protective film of the hot-dip galvanized angle steel.

The thickness of the zinc coating directly affects the roughness of the surface of the galvanized angle steel. When the zinc layer is thicker, due to the difference in thermal expansion and contraction between the zinc and the steel substrate, the zinc layer is prone to forming microcracks during the cooling process, resulting in a rough surface. This phenomenon is more obvious when the zinc layer is thicker.

During the hot-dip galvanizing process, the roughness of the surface of the angle steel will also be affected to a certain extent during the period from the time the angle steel is taken out of the zinc bath to the end of cooling. If the cooling process is too rapid, the atomic structure on the surface of the zinc layer cannot be completely smooth, resulting in a rough surface. In addition, if the angle steels are stacked together without being properly isolated after hot-dip galvanizing, the heat generated by friction will aggravate the roughening of the surface of the zinc layer.

In addition, the composition and surface conditions of the steel used also affect the roughness of the galvanized layer. Different steel compositions and surface treatment methods will result in different parameters such as the bonding strength and surface flatness of the zinc layer and the steel substrate, which will in turn affect the final appearance of the galvanized layer. Impurities such as scale and oil on the surface of the steel will increase the roughness of the zinc layer and affect its flatness.

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