scholarly journals Analysis of the Mixing of Filler and Base Materials in Arc-Welded Single-Bead Surface Welds Using an EDXS Method

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 217
Author(s):  
Borut Zorc ◽  
Matija Zorc ◽  
Aleš Nagode
Keyword(s):  
Chemical Composition ◽  
Cross Sections ◽  
Steel Plate ◽  
Influencing Factor ◽  
Base Material ◽  
Arithmetic Means ◽  
X Ray ◽  
Base Materials ◽  
Bead Surface ◽  
Single Bead

This article deals with an analysis of mixing and determines the admixing rate of a base S355 steel plate in single-bead surface welds by measuring the chemical composition using a plane-scan energy dispersive X-ray spectroscopy (EDXS) on metallographic cross-sections. The results show that obtaining a larger number of EDXS measurements does not necessarily lead to obtaining a more accurate admixing rate. Due to the ever-present segregations that are generally near the base material, the disadvantage of this method is the subjective influence of the SEM operator on the estimated admixing rate. To obtain relevant results, a sufficiently wide area of well-mixed melt, including segregations, must be analyzed. This study showed that by using a sufficiently large number of appropriately selected sites with a sufficiently large surface area, it is possible to estimate the admixing rate from the chemical composition with an accuracy of ≥96% for the geometrically determined admixing rate D = 30%. From several equations, the best result showed an equation which is the arithmetic mean of the two different arithmetic means and in which the artificial influencing factor of the segregations of the base material is taken into account. With this equation, the same value of admixing rate, D = 30%, was obtained using the comparative geometric method.

scholarly journals Determining the Degree of Admixing Rate of the Base Material and the Melting Efficiency in Single-Bead Surface Welds Using Different Methods, Including New Approaches

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1479
Author(s):  
Matija Zorc ◽  
Aleš Nagode ◽  
Borut Kosec ◽  
Borut Zorc
Keyword(s):  
Cross Sections ◽  
Base Material ◽  
Welding Process ◽  
Precise Determination ◽  
Welding Parameters ◽  
Negative Consequences ◽  
Surface Areas ◽  
Bead Surface ◽  
Single Bead ◽  
Surface Welding

The precise determination of the admixing rate of the base material for certain welding parameters is very important because of the possible negative consequences. As such, it is the basis for corrections in welding technology. In the article, experimental and theoretical determinations of the admixing rate in single-bead surface welds that were arc welded onto S355 steel with different alloyed-steel-coated electrodes are discussed. The admixing rate was experimentally estimated from the ratio of the surface areas of metallographic cross-sections, from the ratios of the height and from chemical analyses of different regions of the surface weld, while it was theoretically estimated from the characteristics of the welding process and material constants. One of the key characteristics of the welding process is the melting efficiency, which can be estimated by means of different equations and from knowledge of the heat balance of the welding process. Both the average melting efficiency of the surface welding on the medium-thick S355 steel plate and the average admixing rate of the S355 steel into the surface welds have the same value, i.e., approximately 30%. New equations for estimating the melting efficiency of the arc welding with a coated electrode were developed on the basis of the results.

Influence of Welding Process on the Microstructure of Carbon Steel and Stainless Steel Heterogeneous Welded Joints

2016 ◽  
Vol 1138 ◽  
pp. 31-36
Author(s):  
Maria Cristina Dijmarescu ◽  
Dumitru Titi Cicic ◽  
Corneliu Rontescu ◽  
Gheorhe Solomon
Keyword(s):  
Chemical Composition ◽  
Carbon Steel ◽  
Structural Characterization ◽  
Base Material ◽  
Welding Process ◽  
Cored Wire ◽  
Base Materials ◽  
Flux Cored Arc Welding ◽  
Welded Seam

The reactions of the base material, during the welding process, consist in chemical composition, volume, structure and granulation changes. There are multiple problems which can occur by welding two steels with totally different chemical composition, i.e. carbon steel S235JR + AR and austenitic stainless X2CrNiMo17-12-2. The process used for making the heterogeneous joint was flux cored arc welding (FCAW), numerically coded 136. The paper presents the effects of welding through heat input, on the structural characterization of welded seam and heat affected zone. It also focuses on the structural characterization of the welded joint obtained using the flux cored wire T 23 12 L P C/M 1, and determining how the base materials participate at the formation of the welding joint.

scholarly journals Investigating the interstellar dust through the Fe K-edge

2017 ◽  
Vol 609 ◽  
pp. A22 ◽  
Author(s):  
D. Rogantini ◽  
E. Costantini ◽  
S. T. Zeegers ◽  
C. P. de Vries ◽  
W. Bras ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Cross Sections ◽  
Interstellar Dust ◽  
Effective Area ◽  
European Synchrotron Radiation Facility ◽  
Galactic Centre ◽  
X Rays ◽  
X Ray ◽  
Wide Range ◽  
The Individual

Context. The chemical and physical properties of interstellar dust in the densest regions of the Galaxy are still not well understood. X-rays provide a powerful probe since they can penetrate gas and dust over a wide range of column densities (up to 1024 cm-2). The interaction (scattering and absorption) with the medium imprints spectral signatures that reflect the individual atoms which constitute the gas, molecule, or solid. Aims. In this work we investigate the ability of high resolution X-ray spectroscopy to probe the properties of cosmic grains containing iron. Although iron is heavily depleted into interstellar dust, the nature of the Fe-bearing grains is still largely uncertain. Methods. In our analysis we use iron K-edge synchrotron data of minerals likely present in the ISM dust taken at the European Synchrotron Radiation Facility. We explore the prospects of determining the chemical composition and the size of astrophysical dust in the Galactic centre and in molecular clouds with future X-ray missions. The energy resolution and the effective area of the present X-ray telescopes are not sufficient to detect and study the Fe K-edge, even for bright X-ray sources. Results. From the analysis of the extinction cross sections of our dust models implemented in the spectral fitting program SPEX, the Fe K-edge is promising for investigating both the chemistry and the size distribution of the interstellar dust. We find that the chemical composition regulates the X-ray absorption fine structures in the post edge region, whereas the scattering feature in the pre-edge is sensitive to the mean grain size. Finally, we note that the Fe K-edge is insensitive to other dust properties, such as the porosity and the geometry of the dust.

scholarly journals Joining of γ-TiAl Alloy to Ni-Based Superalloy Using Ag-Cu Sputtered Coated Ti Brazing Filler Foil

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 723 ◽  
Author(s):  
Sónia Simões ◽  
Carlos Tavares ◽  
Aníbal Guedes
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Tial Alloy ◽  
Energy Dispersive ◽  
X Ray ◽  
Base Materials ◽  
Intermetallic Particles ◽  
Scanning Electron

Joining γ-TiAl alloy to Ni-based superalloy Hastelloy using Ag-Cu sputtered coated Ti foil as brazing filler was investigated in this study. Brazing experiments were performed at 900, 950, and 980 °C with a dwelling stage of 10 min in vacuum. The microstructure and the chemical composition of the resulting interfaces were analyzed by scanning electron microscopy (SEM) and by energy dispersive X-ray spectroscopy (EDS), respectively. Sound joints were produced after brazing at 980 °C, presenting a multilayered interface, consisting mainly of Ti-Al and Ti-Ni-Al intermetallics close to the γ-TiAl alloy, and of Ti-rich, Ti-Ni, and Cr-Ni-Mo rich phases near Hastelloy. The hardness of the interface, ranging from around 300 to 1100 HV0.01, is higher than both base materials, but no segregation of either Ag solid solution or coarse intermetallic particles was observed. Therefore, the developed brazing filler also avoids the need to perform post-brazing heat treatments that aim to eliminate detrimental extensive segregation of either soft phases or of hard and brittle compounds.

scholarly journals Diffusion Bonding of Ti6Al4V to Al2O3 Using Ni/Ti Reactive Multilayers

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 655
Author(s):  
Marcionilo Silva ◽  
Ana S. Ramos ◽  
M. Teresa Vieira ◽  
Sónia Simões
Keyword(s):  
Thin Films ◽  
Diffusion Bonding ◽  
Mechanical Characterization ◽  
Base Material ◽  
Microstructural Characterization ◽  
Multilayer Thin Films ◽  
X Ray ◽  
Distribution Maps ◽  
Base Materials

This paper aims to investigate the diffusion bonding of Ti6Al4V to Al2O3. The potential of the use of reactive nanolayered thin films will also be investigated. For this purpose, Ni/Ti multilayer thin films with a 50 nm modulation period were deposited by magnetron sputtering onto the base materials. Diffusion bonding experiments were performed at 800 °C, under 50 MPa and a dwell time of 60 min, with and without interlayers. Microstructural characterization of the interface was conducted through scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). The joints experiments without interlayer were unsuccessful. The interface is characterized by the presence of a crack close to the Al2O3 base material. The results revealed that the Ni/Ti reactive multilayers improved the diffusion bonding process, allowing for sound joints to be obtained at 800 °C for 60 min. The interface produced is characterized by a thin thickness and is mainly composed of NiTi and NiTi2 reaction layers. Mechanical characterization of the joint was assessed by hardness and reduced Young’s modulus distribution maps that enhance the different phases composing the interface. The hardness maps showed that the interface exhibits a hardness distribution similar to the Al2O3, which can be advantageous to the mechanical behavior of the joints.

Crack Healing in an Alumina/Silicon Carbide Nanocomposite After Grinding and Annealing

1999 ◽  
Vol 581 ◽  
Author(s):  
H.Z. Wu ◽  
J.M. Titchmarsh ◽  
S.G. Roberts ◽  
B. Derby
Keyword(s):  
Silicon Carbide ◽  
Chemical Composition ◽  
Cross Sections ◽  
Surface Crack ◽  
Annealing Process ◽  
Energy Dispersive ◽  
Polished Surface ◽  
Crack Healing ◽  
X Ray ◽  
Small Improvement

ABSTRACTAlumina/silicon carbide nanocomposites are known to show their highest strength levels after surface grinding followed by annealing. After annealing in flowing argon, nanocomposites with very coarsely ground surfaces have strengths exceeding those with a finely polished surface. Specimens with lapped surfaces also show a small improvement in strength on annealing. TEM investigations of annealed cross-sections show that the annealing process leads to surface crack healing. The chemical composition of the subsurface region has been studied, and reactive products on and close to the nanocomposite surface after annealing have been investigated by energy dispersive X-ray analysis in the STEM.

STUDY INTO STRUCTURE AND PROPERTIES OF SOLDERS BASED ON ALUMINUM AND ZINC IN THE FORM OF SMALL-SECTION CAST BARS

2018 ◽  
pp. 39-47
Author(s):  
K. V. Nikitin ◽  
I. Yu. Timoshkin ◽  
V. I. Nikitin
Keyword(s):  
Solid Solution ◽  
Cross Sections ◽  
Base Material ◽  
Material System ◽  
Solder Alloys ◽  
Solid States ◽  
Base Materials ◽  
Cast Alloys ◽  
Solder Microstructure ◽  
Gap Width

The study covers Al–Cu–Si (A34 grade) and Zn–Al–Cu (Welco52 grade) solders. It is found that A34 solder (Al–28%Cu–6%Si) melts and crystallizes in a narrow range of temperatures (~18 °C). Solidus and liquidus temperatures of A34 solder are ~508 °С and ~526 °С, respectively. Zn–Al–Cu (Zn–4%Al–2,5% Cu) solder has a eutectic composition, so it melts and crystallizes at a constant temperature of ~389 °С. Densities of investigated solders in their liquid and solid states are studied. A34 solder has a density of 3,02 and 3,32 g/cm3 , respectively. Zinc solder density is 6,28 g/cm3 in the liquid state, and 6,69 g/cm3 in the solid state. The influence of casting conditions on the structure of cast alloys in the form of bars with cross sections of 13, 10, and 5 mm2 was investigated. Main structural components of solder alloys reduce in size as cross sections decrease. The aluminium-based solid solution dendrites and CuAl2 phase are reduced in the A34 solder microstructure. In zinc solders, the most severely reduced ones are zinc-based solid solution dendrites. The best castability is observed in melts obtained from 5 mm2 section bar solders with studied sample gaps of 2,0, 1,5 and 1,0 mm. Eutectic zinc solder features better castability in comparison with A34: castability of the melt obtained from the 5 mm2 section zinc solder rod with a sample gap width of 2,0 mm is 100 % (for A34 melt solder obtained from a rod of the same cross section it was 98 %). Experiments on soldering AK12 alloy plates and 3003 alloy sheets demonstrated that there is a tight border in the solder/base material system and no any defects such as pores or unsoldered areas. There was a slight interpenetration of solder alloys into base materials, especially when soldering AK12 cast plates.

scholarly journals Structure and tribological properties of wear-resistant layers produced in process of plasma powder surfacing

2019 ◽  
Vol 91 (5) ◽  
pp. 35-41
Author(s):  
Tomasz Marek Poloczek ◽  
Artur Czupryński ◽  
Marcin Żuk ◽  
Marek Chruściel
Keyword(s):  
Chemical Composition ◽  
Tribological Properties ◽  
Abrasion Resistance ◽  
Light Microscope ◽  
Base Material ◽  
Resistant Steel ◽  
Wear Resistant ◽  
X Ray ◽  
Resistant Layer ◽  
Resistance Tests

The following study presents the results of wear-resistant layer made of Ni-Cr-Si-B-Fe-C+WC alloy in the form of metallic powder on the AISI 4715 steel. Hardness and abrasion resistance tests were performed in accordance to PN-EN ISO 6508-1:2016 and ASTM G65-00 standards. Obtained data were compared to the abrasion resistant steel produced by Swedish manufacturer. Microscopic observations were made to determine the structure of obtained layer and base material using Olympus SZX9 stereoscopic light microscope. In order to determine the chemical composition of microregions, X-ray microanalysis researches were carried out.

SIGMAL: A Program for Calculating L-Shell lonization Cross-Sections

1981 ◽  
Vol 39 ◽  
pp. 198-199 ◽  
Author(s):  
R.F. Egerton
Keyword(s):  
Cross Sections ◽  
Fortran Program ◽  
Absorption Data ◽  
X Ray ◽  
Atomic Electrons ◽  
Energy Dependent ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
X Ray Absorption ◽  
Shell Ionization

SIGMAL is a short (∼ 100-line) Fortran program designed to rapidly compute cross-sections for L-shell ionization, particularly the partial crosssections required in quantitative electron energy-loss microanalysis. The program is based on a hydrogenic model, the L1 and L23 subshells being represented by scaled Coulombic wave functions, which allows the generalized oscillator strength (GOS) to be expressed analytically. In this basic form, the model predicts too large a cross-section at energies near to the ionization edge (see Fig. 1), due mainly to the fact that the screening effect of the atomic electrons is assumed constant over the L-shell region. This can be remedied by applying an energy-dependent correction to the GOS or to the effective nuclear charge, resulting in much closer agreement with experimental X-ray absorption data and with more sophisticated calculations (see Fig. 1 ).

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