The results of structural research of welded joints between pearlitic high-carbon steel and austenitic chrome-nickel steel obtained by contact welding are presented. As a result of the diffusion process and mechanical mixing of steels local alloyed areas surrounded by pearlitic colonies of high-carbon steel are formed in the transition zone of the weld. The transmission electron microscopy (TEM) has been employed. The formation of the austenitic-martensitic microstructure occurs due to reducing the amount of alloying elements in local areas as compared to the original austenitic chrome-nickel steel chemical composition. Both austenite and martensite have crystallographic characteristics with the following orientation relationships: [211] γ-Fe || [011] α-Fe; [11-1] γ-Fe || [-110] α-Fe. The presence of high-strength local regions in the transition area may lead to a significant reduction in сrack resistance of dissimilar steels welded joints.

This paper shows the results of solving a 3D problem to define types of structures and tensions which can appear during the butt contact welding process of dissimilar steels through low carbon steel inserts. The finite element method to calculate welded structures was used. The thickness of inserts was the main variable parameter. According to the results of numerical simulation using inserts can increase the reliability of welded joints between pearlitic high-carbon steel and austenitic chromium-nickel steel. The best result was obtained by using an insert with a thickness less than 20 mm. Structural studies of the welded joints between high-carbon steel and chromium-nickel steel through low-carbon inserts confirm the results of mathematical modeling.

In this paper combined Hadfield steel - stainless steel - rail steel compounds are considered. Structural studies and estimation of mechanical properties showed that using an intermediate layer of low-carbon steel with 0.2 C wt. % and 5-20 mm thick between high-carbon steel and chromium-nickel steel in the formation of welded joints increases the reliability of connections by reducing the amount of high-strength zones as compared to compounds without a barrier layer.

The surface layer of steel was reinforced by electron-beam cladding at air atmosphere. Two types of powder mixtures were used to receive coatings: (1) titanium and graphite, (2) titanium and boron carbide. The formation of heterogeneous structure was observed in specimens after the electron-beam treatment by the methods of optical microscopy and scanning electron microscopy. The X-ray diffraction analysis was used to analyze the phase composition of the coatings. The wear resistance level of the coatings was estimated by friction test against loosely fixed abrasive particles. It was found that surface alloying of steel with carbon containing components led to the formation of material with an enhanced wear resistance level.