Failure analysis of packing plate in a super high-pressure compressor

This paper presents failure analysis on cracking of packing plate in a super high-pressure compressor. Analytical stresses resulted from shrink-fit assembly are introduced and related with the diametric interference to quantitatively study the influence of diametric interference on local stresses in the packing plate. Residue stresses in the region of interest are measured by X-ray diffraction method under the assembly and disassembly states of the packing plate respectively. In addition, fractographic and metallurgical examinations are carried out to check characteristics of the crack and possible material defects. Our failure analysis indicated that the main reason for the cracking of packing plate is the synergistic effect of the inclusions in the material and the high tensile stresses due to less diametric interference and stress concentration at the crack initiation site.

► We find reasons for the failure of packing plate.
► Less diametric interference leads to the high tensile stresses in the packing boxes.
► Residual stress exists because of unqualified forging treatment.
► Inclusions in the inner disk material reached grade 3.