Comparative study on microstructures and properties of air-cooled and water-cooled Fe-based plasma arc cladding layers

In-situ V carbides reinforced Fe-based plasma arc cladding layers were prepared in the condition of air-cooled and water-cooled substrate, the microstructure, grain size and properties were comparatively studied. Results showed that microstructures of the two cladding layers were lath martensite. When the substrate was water-cooled, the residence times above 1495 degrees C decreased 46.3%, and the average cooling rates above 870 degrees Cincreased 53.3%. The average grain size of the layers' matrix and carbides was clearly refined from 3.12 to 1.39 mm and from 0.37 to 0.09 mm, respectively. Moreover, the depth of heat-affected zone reduced by 14.3%, and the dilution rate reduced by 16.90%. The comprehensive per-formances of the water-cooled cladding layer were obviously improved. The microhard-ness increased from 258 to 1040 HV0.2, the corrosion resistance increased 2.10 times and was about 13.75 times that of the low-carbon steel substrate.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).