What are the causes of cracking of nickel alloy coating? The causes of cracks in the coating are: (1) cracks due to internal defects of the base metal of the copper plate expand outward, causing cracks in the plating layer. (2) Due to the metallographic structure of the alloy plating layer, impurities exist in the crystal phase, and metal bonds and bits are present. The internal stress that is formed by mistake, under the action of molten steel, protective slag, steam, water, etc., some substances such as sulfur, phosphorus aluminum, silicon and other compounds and their compounds, including crystal corrosion, surface vulcanization, oxidation, etc. Reflection and role