Wear State Inspection Of Ferromagnetic Materials On Metal Magnetic Memory Testing For Remanufacturing

Remanufacture technology is used for repairing the wear surface of mechanical components,which helps to improve the surface property and reduce the materials consumption.The wear damage detection of ferromagnetic materials is an important link in remanufacturing repairing engineering,which determines the remanufacturability of the core component and the service performance of the remanufactured component.As a weak magnetic nondestructive testing technology,metal magnetic memory testing(MMMT)technology has a good application prospect in evaluating the wear degree and wear state of the ferromagnetic components.In this paper,the magnetic memory effect on wear surface during the frictional process is studied to put forward the evaluation method of wear state based on magnetic memory test.It provides a reference for weak magnetic detection technology in the remanufacturability evaluation of ferromagnetic materials.This paper firstly investigates the magnetic memory effect of the remanufacturing core during cyclic frictional process.45 steel was chosen to perform the tribological experiment,and the magnetization phenomenon on wear surface was detected.The variation of magnetic memory signals under different frictional cycles was analyzed,and the relationships between tribological parameters and magnetic memory signal characteristics were established to quantitatively evaluate the wear state of remanufacturing core.Then,the friction damage of remanufacturing core under uni-directional single heavy load was characterized by using magnetic memory signal.Ferromagnetic materials were used to simulate the interference fit impeller-shaft assembly to perform the disassembling experiment.The friction damage characteristics caused by different normal loads on the disassembled surface were analyzed,and the surface friction damage was detected by MMMT.The quantitative relationships between the average surface damage depth and the characteristic parameters of magnetic memory signal were obtained to explore the magnetic memory assessment method of disassembling damage,which provides a reference for the judgement of remanufacturability and the selection of repairing technology for disassembled products.At last the plasma sprayed cladding layer was made to conduct the tribological experiment,and the variations of magnetic memory signals on the wear surface with different microhardness were investigated before and after the tribological experiment.The relationships between different normal load and sliding speed on the magnetic signal were clarified to detect and assess the friction behavior and wear degree of cladding layer in service by MMMT.