Electron Microscopy Investigation of Inconel 625 Weld Overlay on Boiler Steel

2015 ◽  
Vol 231 ◽  
pp. 113-118 ◽  
Author(s):  
Paweł Petrzak ◽  
Marek Blicharski ◽  
Stanisław Dymek ◽  
Monika Solecka
Keyword(s):  
Electron Microscopy ◽  
Chemical Composition ◽  
Base Metal ◽  
Light And Electron Microscopy ◽  
Alloying Elements ◽  
Inconel 625 ◽  
Main Element ◽  
Secondary Phases ◽  
Boiler Steel ◽  
Weld Overlay

The investigation was focused on the microstructure characterization as well as changes in chemical composition and hardness of water wall tubing weld overlaid with Inconel 625. The analysis comprised studies in a light and electron microscopy scale that included the evaluation of weld overlays microstructure and microsegregation of alloying elements across the overlay and base metal interface. The particular attention was turned to the distribution of the main element content (Fe, Ni, Mo, Nb, Cr) in the base metal fusion zone as well as in the weld overlay itself. It was shown that the solidification process resulted in significant segregation in alloying elements giving rise to the substantial differences in chemical composition between dendrite cores and interdendritic spaces. It is believed that the microsegregation together with precipitation of secondary phases may contribute to the deterioration of corrosion resistance and overall mechanical properties of weld overlay including ductility and fracture toughness.

Susceptibility to Underclad Cracking in Relation to Chemical Composition

1976 ◽  
Vol 98 (4) ◽  
pp. 342-347 ◽  
Author(s):  
R. Kume ◽  
H. Okabayashi ◽  
M. Amano
Keyword(s):  
Chemical Composition ◽  
Base Metal ◽  
Stainless Steels ◽  
Weld Overlay ◽  
Ferritic Stainless Steels ◽  
Stress Relieving ◽  
Covered Electrodes ◽  
Overlap Area ◽  
Cracking Tendency ◽  
Cladding Material

Heat-affected zone cracking under the weld-overlay-cladding has been investigated for the combination of 22 kinds of ferritic base metals and electrodes including strip electrodes of austenitic and ferritic stainless steels, Inconel and mild steel, and covered electrodes of austenitic and ferritic stainless steels and Inconel. The results indicate that (1) intercrystalline cracks form on stress relieving under the overlap area of the cladding beads, (2) the susceptibility to cracking depends markedly on the chemical composition of the base metal, and the following equation predicts cracking tendency, ΔG = [Cr] + 3.3 [Mo] + 8.1 [V] − 2, and (3) cracking is avoided or decreased by using cladding material which is similar in thermal expansion coefficient to base metal.

Laser treatment with 625 Inconel powder of hot work tool steel using fibre laser YLS-4000

2018 ◽  
Vol 2 (92) ◽  
pp. 60-67
Author(s):  
L.A. Dobrzański ◽  
E. Jonda ◽  
W. Pakieła ◽  
M. Dziekońska
Keyword(s):  
Chemical Composition ◽  
Laser Treatment ◽  
Laser Cladding ◽  
Tool Steel ◽  
Heat Affected Zone ◽  
Base Material ◽  
Substrate Material ◽  
Inconel 625 ◽  
Fibre Laser ◽  
Weld Overlay

Purpose: The purpose of this investigation was to determine the changes in the surface layer (Inconel 625), obtained during the laser treatment of tool-steel alloy for hot work by the use high-power fibre laser. Design/methodology/approach: Observations of the layer structure, HAZ, and substrate material were made using light and scanning microscopy. The composition of elements and a detailed analysis of the chemical composition in micro-areas was made using the EDS X-ray detector. The thickness of the resulting welds, heat affected zone (HAZ) and the contribution of the base material in the layers was determined. Findings: As a result of laser cladding, using Inconel 625 powder, in the weld overlay microstructure characteristic zones are formed: at the penetration boundary, in the middle of weld overlay and in its top layer. It was found that the height of weld overlay, depth of penetration, width of weld overlay and depth of the heat affected zone grows together with the increasing laser power. Practical implications: Laser cladding is one of the most modern repair processes for eliminating losses, voids, porosity, and cracks on the surface of various metals, including tool alloys for hot work. Laser techniques allow to make layers of materials on the repaired surface, that can significantly differ in chemical composition from the based material (substrate material) or are the same. Originality/value: A significant, dynamic development in materials engineering as well as welding technologies provides the possibility to reduce the cost of production and operation of machinery and equipment, among others by designing parts from materials with special properties (both mechanical and tribological) and the possibility of regeneration of each consumed element with one of the selected welding technologies.

scholarly journals Microsegregation and Precipitates in Inconel 625 Arc Weld Overlay Coatings on Boiler Pipes / Mikrosegregacja I Wydzielenia W Powłokach Ze Stopu Inconel 625 Napawanych Łukowo Na Rury Kotłowe

2015 ◽  
Vol 60 (4) ◽  
pp. 2599-2606 ◽  
Author(s):  
M. Rozmus-Górnikowska ◽  
M. Blicharski
Keyword(s):  
Electron Microscope ◽  
Inconel 625 ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Weld Overlay ◽  
X Ray ◽  
Transmission Electron ◽  
Overlay Coatings ◽  
Weld Overlays ◽  
Scanning Electron

The aim of this work was to investigate the microsegregation and precipitates formed due to segregation in Inconel 625 arc weld overlay coatings on boiler pipes. Examination of microsegregation and precipitates were carried out by means of a scanning electron microscope (SEM) equipped with an EDS detector as well as a transmission electron microscope (TEM) equipped with a HAADF (STEM) and an EDS detectors. The presence of precipitations in the weld overlay was also confirmed with X-ray diffraction analysis (XRD) of residue in the form of powder that remained after the electrolytic dissolution of weld overlay matrix. The investigations showed that the interdendritic regions were considerably enriched during microsegregation with Nb, and less so with Mo. The distribution of Cr and Fe in the weld overlay is relatively uniform. The value of the partition coefficient k for Mo and Nb is lower than 1. Therefore, these elements segregate during solidification into the liquid and, once solidification is finished, the interdendritic regions are considerably enriched with these elements. The value of k for Cr, Ni and Fe are only slightly higher than 1. Though the Inconel 625 is a solid-solution strengthened alloy, precipitation of secondary phases occurs in weld overlays. Precipitations were identified as a Laves phase and carbonitrides (Nb, Ti)(C, N).

Influence of Boiler Pipe Cladding Techniques on their Microstructure and Properties

2013 ◽  
Vol 58 (4) ◽  
pp. 1093-1096 ◽  
Author(s):  
M. Rozmus-Górnikowska ◽  
M. Blicharski ◽  
J. Kusińsk ◽  
L. Kuslnski ◽  
M. Marszyck
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Base Material ◽  
Inconel 625 ◽  
Weld Overlay ◽  
Overlay Coating ◽  
Microstructure And Properties ◽  
Microstructure And Mechanical Properties ◽  
Steel Boiler

Abstract The aim of this work was to investigate different weld overlay coating technologies applied to steel boiler pipes and their influence on microstructure and properties of the produced overlays. The investigations were carried out on the boiler pipes weld overlaid by an Inconel 625 and cladded at various conditions (CMT, GMAW and GTAW). The investigations showed that microstructure and mechanical properties of overlaid pipes depend on cladding technology and the chemical composition of the base material.

A Possibility of Using Ion-Track Matrices based on Polyesters to Create Artificial Connective Tissue

2021 ◽  
Vol 37 (5) ◽  
pp. 66-71
Author(s):  
D.V. Petrova ◽  
N.A. Koshlan ◽  
I.I. Vinogradov ◽  
Y.V. Bogdanova ◽  
I.V. Koshlan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Tissue Engineering ◽  
Chemical Composition ◽  
Connective Tissue ◽  
Pore Diameter ◽  
Light And Electron Microscopy ◽  
Chinese Hamster ◽  
Proliferation Rate ◽  
Track Membranes ◽  
Polyethylene Terephtalate

Abstract-The cultivation of Chinese hamster fibroblasts (line V79) on ion-track membranes of various polyesters has been tested. Light and electron microscopy were used to take photographs of polyester membranes with fibroblasts grown on them, which indicated the attachment and proliferation of cells on ion-track adhesive surfaces. The greatest survival of fibroblasts was observed on ion-track membranes with a pore diameter of up to 0.5 μ. It was shown that the chemical composition of the track membrane affects the survival and proliferation rate of Chinese hamster fibroblasts. Polyethylene terephtalate and polyethylene naphtalate membranes provided the highest percentage of grown colonies and the greatest proliferation rate of cells. Track-etched polyester membranes can be used to create adhesive surfaces for the cultivation of fibroblasts and the production of artificial connective tissue. Key words: ion-track membranes and technologies, tissue engineering, fibroblasts, burn therapy

scholarly journals Effect of Ti, Al, Si on the Structure and Mechanical Properties of Boron-Rich Fe–B–C Alloys

2021 ◽  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Alloying Elements ◽  
Secondary Phases ◽  
X Ray ◽  
Solubility Behavior ◽  
Atomic Radii ◽  
Scanning Electron

The effects of substitution of Fe in the boron-rich Fe–B–C alloys, containing 10.0–14.0 % B; 0.1–1.2 % C; Fe – the remainder, 5.0 % Ti, Al, or Si (in wt. %) have been studied with optical microscopy, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy. Mechanical properties, such as microhardness and fracture toughness, have been measured by Vickers indenter. The microstructure of the master Fe–B–C alloys cooled at 10 and 103 K/s consists of primary dendrites of Fe(B,C) solid solution and Fe2(B,C) crystals. It has been found that titanium has the lowest solubility in the constituent phases of the Fe–B–C alloys, with preferential solubility observed in the Fe(B,C) dendrites, where Ti occupies Fe positions. This element has been shown to be mainly present in secondary phases identified as TiC precipitates at the Fe2(B,C) boundaries. Titanium slightly enhances microhardness and lowers fracture toughness of the boron-rich Fe–B–C alloys due to substitutional strengthening of Fe(B,C) dendrites and precipitation of the secondary phases. The level of the content of Al or Si in the Fe(B,C) and Fe2(B,C) solid solutions and quantity of the secondary phases observed in the structure suggest that more Al or Si are left in the constituent phases as compared with Ti. These elements mainly enter the crystal lattice of Fe2(B,C) phase replacing iron atoms and form at their boundaries AlB12C and SiC compounds respectively. The additions of Al and Si to the boron-rich Fe–B–C alloys help to modify their fragility: while they slightly decrease microhardness values, addition of these elements improves the fracture toughness of the constituent phases. Increase in a cooling rate from 10 to 103 K/s does not bring about any noticeable changes in the solubility behavior of the investigated alloying elements. The rapid cooling gives rise to microhardness and fracture toughness of the phase constituents which average sizes significantly decrease. The effects of the alloying elements on the structure and mechanical properties of the investigated boron-rich Fe–B–C alloys have been explained considering differences in the atomic radii and electronic structure of the solute Ti, Al, or Si atoms.

scholarly journals Microstructure and Microsegregation of an Inconel 625 Weld Overlay Produced on Steel Pipes by the Cold Metal Transfer Technique

2014 ◽  
Vol 59 (3) ◽  
pp. 1081-1084 ◽  
Author(s):  
M. Rozmus-Górnikowska ◽  
Ł. Cieniek ◽  
M. Blicharski ◽  
J. Kusiński
Keyword(s):  
Solid Solution ◽  
Chemical Composition ◽  
Pearlitic Steel ◽  
Metal Transfer ◽  
Inconel 625 ◽  
Cold Metal Transfer ◽  
Weld Overlay ◽  
Steel Pipes ◽  
Cold Metal ◽  
Weld Overlays

Abstract The aim of this work was to investigate the development of microstructure and variations in chemical composition in commercial Inconel 625 coatings on a ferritic-pearlitic steel overlaid by the CMT method.The investigation showed that microsegregation occurring during the weld overlay solidification makes the dendrite cores to be richer in Ni, Fe and Cr and in the between dendrite arms in Mo and Nb. Niobium shows the strongest tendency to segregation during solidification; molybdenum tends to segregate less and chromium has the lowest tendency to segregation. Although Inconel 625 is a solid solution strengthened alloy, Nb and Mo-rich phases are formed in the between dendrite arms of weld overlays.

scholarly journals TEM Microstructure and Chemical Composition of Transition Zone Between Steel Tube and An Inconel 625 Weld Overlay Coating Produced by CMT Method

2017 ◽  
Vol 62 (2) ◽  
pp. 787-793 ◽  
Author(s):  
M. Rozmus-Górnikowska ◽  
M. Blicharski
Keyword(s):  
Chemical Composition ◽  
Transition Zone ◽  
Room Temperature ◽  
Ion Beam ◽  
Base Material ◽  
Steel Tube ◽  
Inconel 625 ◽  
Cold Metal Transfer ◽  
Weld Overlay ◽  
Overlay Coating

AbstractThe aim of this work was to investigate the microstructure and chemical composition of the transition zone between 16Mo3 steel and Inconel 625 weld overlay coating produced by the Cold Metal Transfer (CMT) method. Investigations were primarily carried out through transmission electron microscopy (TEM) on thin foils prepared by FIB (Focus Ion Beam).The chemical analysis demonstrated that the amount of certain elements (Fe, Ni, Cr, Mo, Nb) in the transition zone between the base material and the weld overlay changes quickly, from the composition of the steel to the composition of the composite zone. STEM and TEM investigations revealed that two areas are clearly visible in the transition zone. In the narrow band close to the fusion boundary where plates are clearly visible and theMstemperature is higher than room temperature, electron diffraction analyses show reflections of martensite and austenite. Moreover, the crystallographic relations between martensite and austenite can be described by the Kurdjumov-Sachs (K-S) relationship$\{ 110\} _{\alpha '} ||\{ 111\} _\gamma < 1\bar 11 > _{\alpha '} || < 1\bar 10 > _\gamma $). The microstructure of the part of the transition zone with anMstemperature lower than room temperature as well as that of the composite zone is austenite. The investigations proved that the width of the martensitic area can be significantly limited by using the CMT technique for weld overlaying.

scholarly journals Predicting the composition of primary carbides of the multicomponent system Ni-5Cr-9Co-6Al-8.3W-4Re-4Ta-1Mo-1.5Nb-0.15C

2021 ◽  
Vol 2 (92) ◽  
pp. 109
Author(s):  
Vadim Ol'shanetskii ◽  
Olexander Glotka
Keyword(s):  
Electron Microscopy ◽  
Experimental Data ◽  
Chemical Composition ◽  
Total Concentration ◽  
Technical Problem ◽  
Multicomponent System ◽  
Integrated Approach ◽  
Alloying Elements ◽  
Primary Carbide ◽  
Primary Carbides

Abstract. Problem. Development of new and optimization of existing casting alloys for the manufacture of blades of gas turbine engines for various purposes is an important scientific and technical problem. Given the sensitivity of the structural components to the concentration of alloying elements, there are difficulties in assessing the expected set of properties of the blades from the optimization of the chemical composition or structural state of alloys. Goal. The aim of this work is to study the specifics of the influence of alloying elements on the distribution of primary carbides in the structure, their topology, morphology and their composition for a multicomponent system such as Ni-5Cr-9Co-6Al-8,3W-4Re-4Ta -1Mo-1 , 5Nb-0.15C using the calculation method of CALPHAD prediction (passive experiment) in comparison with the data obtained by electron microscopy (active experiment). Methodology. Modeling of thermodynamic processes occurring during crystallization (cooling) or heating in the structure of alloys was carried out by the CALPHAD method. Results. The results of thermodynamic calculations of the chemical composition of carbides are presented in comparison with experimental data obtained by electron microscopy on a microscope REM-106I with a system of energy-dispersion X-ray spectral microanalysis. Originality. It is shown that when the total concentration of carbide-forming elements increases, the chemical composition of carbides also becomes more complicated. At a concentration of more than 2% of the mass. But in the alloy, in the carbide of MS, the content of tantalum prevails over the content of niobium, it also leads to a decrease in the concentration of tungsten and molybdenum in the carbide. It was found that when the concentration of niobium is more than 3 wt%. in the alloy, its content in the primary carbide exceeds the content of tantalum and the carbide becomes based on Ta. Practical value. On the basis of an integrated approach, computational and experimental, for multicomponent heat-resistant alloys, new regression models are obtained that allow to adequately predict the chemical composition of carbides by the chemical composition of the alloy. which is confirmed by the obtained experimental data.

The Morphology of Vacuolated Cells in the Liver Following Administration of Vitamin A.

1973 ◽  
Vol 31 ◽  
pp. 408-409
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti
Keyword(s):  
Electron Microscopy ◽  
Body Weight ◽  
Vitamin A ◽  
Light And Electron Microscopy ◽  
Liver Cells ◽  
Prominent Feature ◽  
Vascular Space ◽  
Vacuolated Cell ◽  
Vacuolated Cells ◽  
Vacuolated Cytoplasm

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).

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