The article mainly focused on analyzing the cause of formation of phosphate coating film speckles on the outer ring of bearings in the manufacturing progress of railway bearing in Xibei Bearing Co.

• 摘要针对西北轴承股份有限公司铁路轴承外套在生产过程中，突然出现磷化膜颜色深浅不均匀的云彩状花斑，进行成因分析。