Electron microscopic analysis of a metal layer deposited with tungsten-containing powder wire

The effect of replacement of powdered tungsten and graphite in flux-cored wire with tungsten oxides and carbon-fluorine-containing material during surfacing with flux-cored wire on the qualitative characteristics of the deposited metal layer was investigated by scanning electron microscopy methods. The metal of the sample with metallic tungsten powder has a dendritic structure and is distinguished by a pronounced diversity of grain. The grains are large, irregularly shaped, ranging in size from 30 to 150 μm. The microstructure of the sample is biphasic and consists of a solid solution of tungsten in iron and an intermediate phase. The tungsten concentrate sample metal has a more uniform microstructure. Grains are equiaxial, almost regular octahedral in shape. The grain size corresponds to 1.5 points ac-cording to GOST 5639–82 (the average grain diameter is 200 μm). The structure of the sample is single-phase, it is a solid solution of tungsten in -iron, similar to the needle-like structure of Widmatstätt ferrite with a border of free ferrite in iron-carbon steels. The deposited metal of both samples is characterized by a high degree of purity in terms of non-metallic inclusions. In a steel sample using tungsten metal, globular inclusions of aluminosilicates and point inclusions of iron and tungsten oxides were found. In a sample of steel using a tungsten concentrate with a reducing agent, non-metallic inclusions of a complex composition based on oxides of iron, tungsten and manganese sulfides predominate during surfacing and non-metallic inclusions of a complex composition based on manganese sulfides and aluminosilicates