Electromagnetic stirring laser cladding repairing method for cracks of ultra-high strength steel undercarriage component

Abstract

The invention belongs to the technical field of laser material additive manufacturing and repairing, and relates to an electromagnetic stirring laser cladding repairing method for cracks of an ultra-high strength steel undercarriage component. The electromagnetic stirring laser cladding repairing method is mainly used for repairing the surface cracks on the undercarriage component. The electromagnetic stirring laser cladding repairing method comprises the steps that (1) a material used for laser cladding repairing is prepared; (2) surface cleaning is conducted before repairing; (3) electromagnetic stirring assists laser cladding repairing; (4) machining is conducted; (5) nondestructive testing is conducted; and (6) repairing is finished after stress relief annealing is conducted. Accordingto the electromagnetic stirring laser cladding repairing method for the cracks of the ultra-high strength steel undercarriage component, the average tensile strength of direct laser cladding repairing is 1424.3 MPa, the average extension rate is 11.5%, the average impact toughness is 478 KJ/m<2>, and the average microhardness of repaired metal is 464.6 HV; and the average tensile strength of electromagnetic stirring assisted laser cladding repairing is 1466.7 MPa, the average extension rate is 15.1%, the average impact toughness is 665 KJ/m<2>, and the average microhardness of the repaired metal is 491.4 HV. Deformation of the component is controllable after repairing, the repaired part is free of defect, the repair area is better in room-temperature plasticity and impact toughness, and the service life of the undercarriage component is prolonged.

Description

technical field [0001] The invention belongs to the technical field of laser additive manufacturing repair, and relates to an electromagnetic stirring laser cladding repair method for cracks in ultra-high-strength steel landing gear components, which is mainly used for repairing cracks on the upper surface of aircraft landing gear components. Background technique [0002] When the aircraft landing gear is overhauled, there are micro-cracks on the outer surface of the ultra-high-strength steel piston rod, half shaft and other components of the landing gear. These cracks are fatigue cracks caused by repeated impacts on the landing gear components during service. According to the aircraft maintenance manual According to the above quality inspection guidelines, the landing gear is a key component, and the landing gear components with crack defects are not allowed to be installed and used again. However, ultra-high-strength steel landing gear components such as piston rods and ha...

AI Technical Summary

Problems solved by technology

[0002] When the aircraft landing gear is overhauled, there are micro-cracks on the outer surface of the ultra-high-strength steel piston rod, half shaft and other components of the landing gear. These cracks are fatigue cracks caused by repeated impacts on the landing gear components during service. According to the aircraft maintenance manual According to the above quality inspection guidelines, the landing gear is a key component, and the landing gear components with crack defects are not allowed to be installed and used again

However, ultra-high-strength steel landing gear components such as piston rods and half shafts are large-scale non-wearable parts, and the cost of replacement is extremely expensive and the production cycle of new parts is long, which is difficult to meet the requirements of the maintenance cycle of the whole machine. , the size of these crack defects is very small, so there is an urgent need for a reliable repair technology to repair them

[0003] At present, for this type of parts, the optional repair technologies are argon arc welding and laser cladding. However, due to the high heat input of argon arc welding and the large heat-affected zone, the performance of the base material will be reduced, and high residual stress will be generated at the same time. , causing deformation of the workpiece and cracking of the repaired metal, and there are many connecting and matching components in the landing gear components, which require high dimensional accuracy. The deformation and cracking caused by argon arc welding repair are not allowed. Furthermore, the The material of the landing gear is 300M, 30CrMnSiNi2A and other ultra-high-strength steel, and the weldability is poor. Therefore, it is not suitable to use the argon arc welding repair welding method for the maintenance of the key parts of the piston rod; the laser powder filling repair technology provides a new solution to this problem. way