METHOD OF REPAIR OF METAL PARTS WITH MICRO FLAWS ORIGINATING FROM SURFACE Russian patent published in 2015 - IPC B23P6/00 

FIELD: process engineering.

SUBSTANCE: invention relates to metal parts reconditioning. Propose process comprises identification of zone with dangerous concentration of micro defects and removal of metal by cleaning of said zone with removal of scale and metal therefrom sufficient for optical analysis of said zone. Note here that at least two surface metal plies are removed with determination of surface density (N_s)_i of location of said micro defects after removal of said tow plies. Magnitudes of (Ns)i at different depths h_i from initial cleaned surface are used to defined the relationship N_s=f(h)_i. The latter is extrapolated to unanalysed area of metal removal depth within the limits of total depth h_max of micro defects. Marked are 4-5 points (N_s)_i, including extrapolated values to make several cylindrical equal-initial diameter D₀ from the same metal in amount defined by the number of magnitudes (N_s)_i, D₀ being selected proceeding from extreme load of test machine. Every said specimen is turned to diameter D_i, defined proceeding from equality of stresses in specimen cross-section at preset load of test machine in appropriate part cross-section at working load. Every specimen is relaxed in compliance with the part relaxation by revealed micro defects at depth h_i. For this, circular notch is made at specimen to diameter d_i. Notched specimens are tested to destruction at temperature some (60-70)°C higher than working temperature at equal stress that causes strain in the part with allowance for removed metal play depth. Results of the tests allow selection of specimen with maximum time to specimen destruction for which relationship N_s=f(h)_i is used to determine wanted metal removal depth h_opt.

EFFECT: determination of possible depth of recoverable metal removal.

9 dwg, 4 tbl