Abstract: The copper tube of the compressor of a washing and drying integrated machine cracked within a short period of service. Based on physical and chemical inspection methods, the fracture nature and root cause of the compressor copper tube were determined from the macroscopic shape, microscopic feature, fracture analysis, metallographic analysis, hardness, and material composition of the fracture surface. The results indicate that the fracture of the copper tube belongs to fatigue fracture, and the crack source is located on the inner side of the copper tube. The vibration of the compressor causes the copper tube to experience alternating torsional force, resulting in plastic deformation inside the copper tube. Some severely deformed areas crack, and fatigue cracks propagate outward along the defects on the inside of the pipeline until they penetrate the wall thickness of the pipeline.

Key words: Compressor, Copper tube, Fatigue fracture, Failure analysis