Abstract The work is devoted to the study of bimetallic structures "titanium-steel" by electron beam freeform fabrication with use niobium and copper interlayers. A metallographic deposited interlayers carried out. hardness distribution over samples shown. Technological issues according deposition on titanium steel are pointed Tensile testing results reveal that obtained have an ultimate tensile strength 150–228 MPa fracture located at niobium-copper alloy side or interlayer. need reduce...

This paper presents a study of acoustic emission (AE) during the deformation dissimilar welded joints austenitic steel to pearlitic steel. One specific problems in these is presence decarburized and carbide diffusion interlayers, which intensively increase width long-term high-temperature operation. The wide interlayers negatively affects mechanical properties joints. Moreover, defects are difficult diagnose containing interlayers: due high structural heterogeneity, create noises that can...

In this study, we investigated defect detection in dissimilar welded joints by the acoustic emission (AE) method. The study objects were carbide and decarburized interlayers, which are formed at fusion boundary between austenitic pearlitic steels. Diffusion as a structural defect, usually have microscopic dimensions cannot be detected using conventional non-destructive testing (NDT) methods. regard, AE method is promising approach to diagnose metal with complex structure detect defects....

Fatigue crack in rails and cyclic-loaded train parts is a contributory factor multiple railroad accidents. We address the problem of detection measurement at early stages, when total failure has not yet occurred. propose to combine acoustic emission (AE) testing for prediction growth with digital image correlation (DIC) its accurate quantitative characterization. In this study, we imitated fatigue appearance samples railway rail two by cyclic loading, applied these techniques inspection....

Abstract The influence of the scale effect on strength mechanically inhomogeneous welded structures with a soft zone was studied. investigated samples were made two 12Kh18N10T austenitic steel plates and low-carbon ferritic insert connected between them by dissimilar joints performed electron beam welding. Tensile as function relative thickness for tensile specimens 1.2 to 10 mm plotted. It shown that in range from 0.2 0.5, did not manifest during tension. This can be explained low plastic...

Methods for evaluation of Young’s modulus ( E m ) structural materials by instrumented indentation using ball indenter have been considered. All these techniques are based on the solution elastic contact problems performed H. Hertz. It has shown that registration initial region in «load – displacement» diagram provides determination metals and alloys. However, it is necessary to evaluate accurately compliance a device, use an with large radius R , ensure high surface quality test material...

Abstract Existing analytical methods for calculating electron-beam welding modes, which provide welds with required penetration depth, are described, and main disadvantages of these shown. A new calculation method based on a model moving cylindrical heat source, involves cylinder constant surface temperature in an infinite plate, is proposed. The proposed takes into account energy losses during metal melting its partial evaporation. comparison experimental calculated data obtained using the...

The one-dimensional (1D) linear location technique has been considered as one of the methods for determining position acoustic emission (AE) sources in metallic objects. However, this approach does not take into account heterogeneity materials and that leads to poor accuracy AE localization. To estimate positioning error which is typically used determine source a new based on combination experimental simulation proposed. This estimation contains finite element model construction signals...

<title>Abstract</title> The possibility of obtaining a combined titanium-steel construction by directed energy deposition using vanadium or vanadium/nickel interlayers. Vanadium wire VnPr-1, nickel NP1 grade and welding wires Sv-08G2S, 316L, MSG NiFe-1 grades were used for on the end titanium plate VT1-0. use as an interlayer deposited makes it possible to provide joining with stable structure, steady hardness distribution acceptable manufacturability. content dissolved in layer negatively...

Tensile tests of steel specimens with plotting loaded and unloaded true stress curves were carried out. It is shown that «true – strain» in the necked region tensile specimen have form a sloping ascending straight line up to failure. revealed straightness curve also observed for austenitic structure which martensite formed under effect plastic deformation, whereas S relative area reduction ψ» exhibit violation upward deviation at final stage necking. When using Davidenkov correction,...

The history of appearance and the current state instrumented indentation are briefly described. It is noted that materials methods using a pyramid ball indenters actively developing currently regulated by several Russian international standards. These standards provide formulas for calculating Young’s modulus hardness at maximum load. Instrumented diagrams «load F – displacement α» indenter metallic were investigated. special points on « loading curves in area elastic into elastoplastic...

The research is devoted to steel structure diagnostics by the acoustic emission (AE) method. existing regulatory documents for AE of metals and alloys do not take into account some critical factors, among which one scale factor should be highlighted. As a result, this can lead an unreliable assessment danger degree defects in structures when using standard diagnostic criteria. This paper presents quantitative impact on data during static tension test specimens failure. Experimental studies...

The results of metallographic studies 5V titanium alloy welds obtained with the range electron-beam welding speeds from 20 to 120 m/h are presented. It was established that at all some identical microstructure a weld metal is formed, which can differ only in sizes and shapes primary crystals. Vickers hardness, ultimate tensile stress yield estimation by sample-free indentation methods shown. hardness distribution transverse direction homogeneous while top root an increase values speed modes...

Abstract Low-temperature instrumented indentation tests of welded joints are carried out. The effect metal cooling on diagrams and hardness is investigated. Impact strength with a gradual decrease in temperature the identification cold brittleness threshold determination critical for several structural steels performed. For an express evaluation resistance, parameter γ proposed, which equal to ratio at given low room temperature. relation between coefficient hardness, included equation...

Abstract The results of metallographic studies 5V titanium alloy welds obtained with the range electron-beam welding speeds from 20 to 120 m/h are presented. It was established that at all some identical microstructure a weld metal is formed, which can differ only in sizes and shapes primary crystals. Vickers hardness, ultimate tensile stress yield estimation by sample-free indentation methods shown. hardness distribution transverse direction homogeneous while top root an increase values...

The article discusses the features of producing articles by method electron beam additive forming alloys based on aluminium. technology obtaining a thin wall from deformable aluminium alloy AMg6 is described and results mechanical tests are presented. It shown that properties obtained ELAF meet requirements GOST for various types semi-finished products.

A brief review of known approaches to converting diagrams obtained by indentation into tension is presented. It noted that most studies on the transformation kinetic a spherical indenter are carried out within limits uniform deformation using both computational and experimental including finite element method (FEM) neural networks. However, we consider such from one diagram another can be fulfilled successfully when proper relationship between deformations. This makes it possible obtain more...

Paratellurite TeO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> crystals of various degrees defectiveness were studied under external mechanical loading. The results structural changes in obtained by capturing acoustic emission data and polarized optical microscopy observation. Peculiarities corresponding to defects types are revealed. It has been experimentally shown that monitoring a mechanically loaded paratellurite makes it...