Flash butt welds between high carbon steel and chrome–nickel steel were studied in this article. Light and electron microscopic studies have shown that the welded joints have a complex structure consisting of several phases. In addition to pearlite colonies, austenite microvolumes and regions of high strength martensite, the welds contain brittle inclusions of titanium sulphide and carbide particles. The mechanical behaviour of the welded joints is negatively influenced by the dramatic change in hardness in the weld zone. Fractographic analysis of dynamically fractured welds between carbon steel and stainless steels has shown that the fracture in the weld samples occurs in both steels. This behaviour of the material is caused by the non-uniform distribution of martensitic regions within the weld. The formation of martensitic regions in the structure of the material is a major cause of the reduction in the fatigue crack resistance of the welded joints.

Structure, microhardness and fracture features of coatings produced by atmospheric electron-beam cladding of amorphous boron were investigated. The coatings were produced by cladding of one, two and three layers of powder. Produced coatings thickness is 550, 750 and 900 μm respectively. The peak level of microhardness is 14000…16000 MPa. By the means of XRD analysis it is stated that the main phases of strengthened layers are FeB and Fe₂B borides and eutectic (α-Fe + Fe₂B). The coatings after one layer cladding have non-uniform structure with microvolumes having lack of borides. Three-layered coatings are noted for their high brittleness. The best properties are presented by two-layer coatings.