Influence of Cladding with Flux-Cored Wire on the Structural–Phase State of Steel 20

Using transmission diffraction electron microscopy methods on thin foils, the influence of the metal of surfacing with welding wire of type 0.35С–5Cr–1Mn–1V–1Ni–1W–1Mo–Fe on the structure of the substrate made of steel 20 has been investigated. A quantitative analysis of changes in the fine structure of the substrate and surfacing materials at different distances (0.5 and 3.0 mm) from the fusion line has been performed. The morphological components of the structure, their volume fraction and phase composition have been determined. It has been established that in the initial state, steel 20 is represented by lamellar pearlite and ferrite. Surfacing with welding wire has led to significant destruction of lamellar pearlite, complete fragmentation of ferrite, release of small cementite particles at the boundaries and joints of ferrite fragments, creation of an elastically stressed state of the steel matrix, and strengthening of the substrate by 1.5 times.