Could someone introduce the low-temperature iron plating repair technique?

Main mechanical properties of the iron-plated layer: The microhardness value HV0.1 of the iron-plated layer is 500~600. The wear resistance of the iron-plated layer is equal to or higher than that of quenched 45 steel. In the iron-plated layer, the columnar crystals are perpendicular to the substrate surface; the grains are highly refined with sizes of around 25–50 NM, accounting for 1% of the molten metal. After mechanical (grinding) treatment of the iron-plated layer, the surface appears dense and defect-free when observed macroscopically. The iron-plated layer fuses with the substrate; scraping the iron-plated layer in any part of the specimen does not cause it to separate from the substrate ； When grinding the iron-plated layer to the substrate on a large grinder, no bonding interface can be seen ； The longitudinal and transverse cross-sections of the specimen were polished, etched with 3% nitric acid in alcohol, and then examined under a microscope at a magnification of 400–1000 times; it was possible to observe that the ferrite in the iron-plated layer was continuous with the ferrite in the base material. The specimen was heated to 300–400 degrees, held at that temperature for 1 hour, then removed and immersed in cold water. Subsequently, any part of the coating on the specimen was scraped off, but no delamination was observed at the interface between the coating and the substrate. As long as the inherent strength and fatigue resistance of the part have not reached their limits, the service life of the part after iron plating repair can be comparable to that of a new part