Experimental researches of repair discs of low pressure compressor (LPC) from alloy VT3-1 by methods X-ray diffraction (XRD) are spent. The method of determination of resource of repair disk to change the structural state of the disk material by non-destructive way is developed. The regularities of changes in structural parameters determined from the change in the half, the displacement and intensity of the interference lines, depending on the operating parameters of the disc are developed.