Due to long-term work in harsh environments, the parts of mechanical equipment are prone to corrosion and wear. Typical failure-prone parts include impellers, journals of large rotors, discs, and shaft sleeves. Many of these parts are expensive, and there are many varieties and complex shapes, making it very difficult to repair. However, the use of laser cladding machine to repair worn parts does not require preheating of the workpiece, and the size of the journal can be restored, and the subsequent processing volume is small, and no metallurgical cracks are generated.
Metal Additive Manufacturing Processes of Shaft Parts
(1) Pretreatment process: including degreasing and rust removal on the surface of the workpiece → sandblasting (further cleaning) → pre-cladding treatment (clean the area that needs laser cladding, and level the area with obvious defects);
(2) Quality inspection process: Use magnetic particle inspection, X-ray inspection, fluorescent inspection or display agent inspection method to detect the cleaned surface to determine whether there are obvious defect areas.
(3) Laser cladding: Laser cladding is carried out with alloy powder with independent intellectual property rights, no preheating is required, no metallurgical cracks are generated, and the hardness can reach HRC63.
(4) Follow-up processing: including polishing and finishing and post-processing of the laser cladding area; spray abrasion-resistant coating if necessary.
(5) Quality inspection and acceptance: After confirming that there are no defects on the surface of the parts after laser cladding, the acceptance can be carried out. After the above treatment process, the shaft parts can be restored as new.
Laser Cladding Equipment of Large Gears
(1) Process flow: First, clamp the large gear to the laser processing machine tool to clean the oil stains and rust spots on the gear tooth surface. Secondly, spray light-absorbing paint on the gear surface and the journal part that need laser processing, and use the laser processing procedure to quench the gear surface.
(2) Quenching process parameters: According to the different hardness requirements of the gear on the material surface, the process parameters are changed in sections by the numerical control system to obtain the corresponding laser hardened layer. After laser quenching, there is no need for tempering treatment, and the roughness of the gear surface is basically unchanged.
(3) Laser cladding process index: The thickness of a single layer of laser cladding can be adjusted between 0.2-2.5 mm as required. For large steel gears, it can be directly cladding without preheating, and the cladding layer is uniform and continuous without cracks, pores and other metallurgical defects.
Laser Metal Deposition Process of Turbine Blades
(1) Pretreatment process: including degreasing and rust removal on the surface of the workpiece → sandblasting (further cleaning) → pre-cladding treatment (clean the area that needs laser cladding, and level the area with obvious defects)
(2) Defect detection that needs repair welding: through visual observation and experimental instrument detection, detect the area that needs to be repaired, including wear area, crack area, etc., and record the location that needs to be repaired;
(3) Laser cladding: Laser repair of blades is divided into two categories: one is the repair of micro-cracks, and the other is the extension of the tip of the worn blade. Using pulsed laser cladding technology, by controlling the laser input energy, repetition frequency and laser scanning speed, the laser cladding layer can be controlled to not produce cracks.
(4) Follow-up processing: grinding, polishing and trimming the repaired blades to make the appearance size meet the requirements of the drawings.
(5) Quality inspection: Perform quality inspection on the repaired turbine disk to confirm that the quality of all repaired parts meets the requirements.
(6) Finishing treatment: the surface spray coating and other finishing treatments are carried out on the inspected turbine disk.
Jinan SENFENG Technology Co., Ltd. is dedicated to the industrial application and promotion of laser cladding technology. The company has established a laser cladding technology research and development center, production and processing center. If you want to know more about laser cladding machine, please contact SENFENG LEIMING.
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