Peculiarities of Formation of Residual Stresses in Welded Joints and Stellite Weld Cladding on Rail Steel
| Autor: | A. Yu. Abdurashitov, M. A. Lebedev, A. A. Ashmarin, K. V. Grigorovich, S. Ya. Betsofen |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Cladding (metalworking) Materials science Cementite General Engineering 02 engineering and technology Welding 021001 nanoscience & nanotechnology 01 natural sciences law.invention chemistry.chemical_compound chemistry law Residual stress Stellite 0103 physical sciences Ultimate tensile strength General Materials Science Surface layer Composite material 0210 nano-technology Anisotropy |
| Zdroj: | Inorganic Materials: Applied Research. 11:634-640 |
| ISSN: | 2075-115X 2075-1133 |
| Popis: | Using X-ray diffraction methods, the distributions of residual stresses over the cross section of a welded joint of the rail and in cladding of wear-resistant stellite have been analyzed. The stresses in the welded joint have been determined by the sin2ψ method, and the stresses in stellite cladding have been determined by an original method based on the analysis of the anisotropy of elastic characteristics of the material, which allows one to more accurately estimate the residual stresses in materials with a heterogeneous structure. It is established that the phase composition of rail steel (α-Fe and traces of cementite) in a welded joint remains unchanged over the cross section, while the original textureless state is preserved in all investigated regions of the welded joint. In a welded joint, compressive residual stresses ranging from –412 to –517 MPa in the direction normal to the weld and compressive residual stresses of above 300 MPa in the direction of rail width are formed. This contradicts published data, according to which the tensile stresses in most cases are formed in the joint region owing to the reaction of the material of a heat-affected region to dilatation of the material of a welded joint upon cooling. Compressive residual stresses in the material of a weld joint of rail steel are formed because of the positive volumetric effect of the γ → α transformation. In the surface layer of stellite cladding, tensile stresses of more than 700 MPa are detected. At the same time, residual stresses are absent at a depth of 100–120 μm, which indicates the formation of compressive stresses in the inner part of this layer that compensate tensile stresses in the external sublayer. |
| Databáze: | OpenAIRE |
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