Metal part remanufacturing method adopting stress control and 3D printing

The invention discloses a metal part remanufacturing method adopting stress control and 3D printing. The metal part remanufacturing method comprises steps as follows: firstly, a body sample and a cladding sample of a metal part are prepared, and laser parameters required by the same residual compressive stress are acquired through laser shock; secondly, a to-be-repaired metal part is preprocessed, a repairing area and a repairing allowance of the part are determined with an image recognition method; the metal part is subjected to cladding repair layer by layer by the aid of a laser 3D printer, and the size of a repaired part reaches the originally designed size of the part; finally, residual tensile stress is eliminated through the laser shock, and then a residual compressive stress layer is formed on the working surface of the metal part with a laser shock processing method. According to the metal part remanufacturing method, the part repairing is performed by adopting laser 3D printing, the overall deformation of the part is not large, further, the repairing size precision is easy to control, and follow-up processing is not required; the repaired parts acquire equal overall strength, a value of residual compressive stress of a part surface strengthening layer after the laser shock processing keeps balance, and the service life of the remanufactured part is prolonged.