The Microstructure of Weld Overlay Ni-Base Alloy Deposited on Carbon Steel by CMT Method

2015 ◽  
Vol 231 ◽  
pp. 119-124 ◽  
Author(s):  
Monika Solecka ◽  
Paweł Petrzak ◽  
Agnieszka Radziszewska
Keyword(s):  
Carbon Steel ◽  
Base Alloy ◽  
Dendritic Structure ◽  
Inconel 625 ◽  
Cold Metal Transfer ◽  
Inconel 625 Alloy ◽  
Second Phases ◽  
Transfer Method ◽  
Cold Metal ◽  
Weld Overlays

Ni-base alloys, like Inconel 625, exhibit a high temperature corrosion and oxidation resistance. For this reason, these alloys are typically used as a one of the most important coating material and can be applied in a different environments and elements of devices having various applications. In this work, Inconel 625 was deposited onto a carbon steel P235GH by Cold Metal Transfer method. Due to the segregation of Ni, Cr, Nb and Mo elements the Inconel 625 weld overlays cladded on boiler pipes P235GH obtained the dendritic structure, with the formation of a second phases at the end of solidification. The presence of γ (with high dislocation density), the Laves and (Nb,Ti)C phases was revealed by means of TEM examinations. The multipoint EDS analysis confirmed the presence of low Fe concentration in the Inconel 625 alloy coatings. The concentration profiles of Ni, Cr, Mo and Nb performed across the dendritic structure showed segregation of these elements.

scholarly journals On the Effect of Heat Input and Interpass Temperature on the Performance of Inconel 625 Alloy Deposited Using Wire Arc Additive Manufacturing–Cold Metal Transfer Process

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 46
Author(s):  
Chengxun Zhang ◽  
Zhijun Qiu ◽  
Hanliang Zhu ◽  
Zhiyang Wang ◽  
Ondrej Muránsky ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Inconel 625 ◽  
Heat Accumulation ◽  
Cold Metal Transfer ◽  
Inconel 625 Alloy ◽  
Cold Metal ◽  
Wire Arc Additive Manufacturing ◽  
Interpass Temperature

Relatively high heat input and heat accumulation are treated as critical challenges to affect the qualities and performances of components fabricated by wire arc additive manufacturing (WAAM). In this study, various heat inputs, namely 276, 552 and 828 J/mm, were performed to fabricate three thin-wall Inconel 625 structures by cold metal transfer (CMT)-based WAAM, respectively, and active interpass cooling was conducted to limit heat accumulation. The macrostructure, microstructure and mechanical properties of the produced components by CMT were investigated. It was found that the increased heat input can deteriorate surface roughness, and the size of dendrite arm spacing increases with increasing heat input, thus leading to the deterioration of mechanical properties. Lower heat input and application of active interpass cooling can be an effective method to refine microstructure and reduce anisotropy. This study enhances the understanding of interpass temperature control and the effectiveness of heat inputs for Inconel 625 alloy by WAAM. It also provides a valuable in situ process for microstructure and mechanical properties’ refinement of WAAM-fabricated alloys and the control of heat accumulation for the fabrication of large-sized structures for future practical applications.

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 Prevent Cracking in Deposition of Carbon Steel on Inconel 625

2019 ◽  
Vol 269 ◽  
pp. 03011
Author(s):  
M. A. Morsy ◽  
M. R. El Koussy ◽  
M. M. Farag
Keyword(s):  
Carbon Steel ◽  
Base Alloy ◽  
Inconel 625 ◽  
Dilution Method ◽  
Type Ii ◽  
Grain Refining ◽  
Nickel Base Alloy ◽  
Nickel Base ◽  
Clad Steel ◽  
Welding Procedure

Welding procedure of clad steel including deposition of carbon steel on nickel base alloy usually gives unaccepted mechanical properties. Cracks were formed along type II boundary in nickel base alloy pass and a martensitic layer was formed in carbon steel pass. In this paper, cracks along type II boundary were prevented by lowering the martensitic start temperature (TMs) of the martensitic layer. Decreasing of TMs was obtained by two methods: Dilution method and Grain refining method. Three levels of TMs (approximately 350, 200, and 50⁰C) are obtained. The results showed that: cracks along type II boundary were prevented at TMs lower than 200⁰C; however type II boundary itself was prevented at TMs lower than 50𠜌. Also post weld heat treatment was necessary to achieve accepted impact properties.

Preparation of Ni-Base Alloy Coatings on Monel Alloy by Laser Cladding

2012 ◽  
Vol 472-475 ◽  
pp. 313-316 ◽  
Author(s):  
Chun Hua Zhang ◽  
Yu Xi Hao ◽  
Lin Qi ◽  
Fang Hu ◽  
Song Zhang ◽  
...  
Keyword(s):  
Phase Composition ◽  
Laser Cladding ◽  
Surface Hardening ◽  
Alloy Powder ◽  
Base Alloy ◽  
Dendritic Structure ◽  
Eutectic Phase ◽  
Inconel 625 ◽  
Cladding Layer ◽  
The Matrix

Abstract. The paper presents the results of a study concerned with the surface hardening of Inconel 625 alloys and Ni-base alloy powder on Monel alloy by electro spark deposition and laser cladding processes. The microstructure, the phase composition and the microhardness of samples are investigated by SEM, EDS, XRD and microhardness instrument. It is shown that, the matrix phase is mainly made up of dendritic structure (γ-Ni), interdendritic eutectic phase (Ni3(B,Fe,Si)) and some precipitates (Cr7C3, Cr23C6). Additional, the microhardness of laser cladding layer can be substantially increased, duo to formation of precipitates.

GTAW Welded Inconel 625 Alloy Fuel Cladding for the Canadian SCWR: Microstructure and Mechanical Property Characterization

2020 ◽  
Author(s):  
German Cota-Sanchez ◽  
Lin Xiao
Keyword(s):  
Mechanical Properties ◽  
Grain Growth ◽  
Dendritic Structure ◽  
Base Material ◽  
Mechanical Tests ◽  
Nuclear Industry ◽  
Reactor Fuel ◽  
Inconel 625 ◽  
Fuel Cladding ◽  
Inconel 625 Alloy

Abstract Inconel 625 is considered one of the candidate materials for reactor fuel cladding in the Canadian supercritical water reactor (SCWR) design. Gas tungsten arc welding (GTAW) is being evaluated as a joining technique for SCWR fuel cladding since this method is widely used to join components in the power and nuclear industry. During the GTAW process, the welding thermal cycle produces different types of microstructures in both the heat-affected zone (HAZ) and fusion zone (FZ) that affect the material's mechanical properties. A series of welding experiments at various weld conditions were performed using an automatic GTAW orbital process on Inconel 625 alloy tubing. Simple analytical heat conduction and grain growth models were developed to predict weld temperature profiles and metallurgical transformations. Weld characterization included mechanical tests, optical microscopy, scanning electron microscopy - energy dispersive spectroscopy (SEM-EDS) elemental analysis, and microhardness measurements. Weld microstructural characterization revealed that a characteristic dendritic structure was formed in the FZ, while the HAZ exhibited larger equiaxed grains than those found in the base material. SEM-EDS analysis showed no distinct alloying element segregation in both the HAZ and FZ. Welds produced with heat inputs of about 3.00 kJ/cm3 presented similar mechanical properties as those observed in the base material. In these welds, grain growth was homogenously minimized in the FZ. It is concluded that the effective welding heat input control can optimize the weld microstructure and the weld mechanical properties in Inconel 625 tubing used as Canadian SCWR reactor fuel cladding.

scholarly journals Corrosion Resistance of Inconel 625 CMT-Cladded Layers after Long-Term Exposure to Biomass and Waste Ashes in High-Temperature Conversion Processes

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4374
Author(s):  
Aleksandra Błoniarz ◽  
Marcus Schreiner ◽  
Markus Reinmöller ◽  
Agnieszka Kopia
Keyword(s):  
Chemical Composition ◽  
Inconel 625 ◽  
X Rays ◽  
X Ray Diffraction ◽  
Cold Metal Transfer ◽  
X Ray ◽  
Xrf Scanning ◽  
Corrosion Mechanisms ◽  
Cold Metal

The present study investigated the effect of corrosion on an Inconel 625-cladded layer using the cold metal transfer (CMT) method. The corrosion was caused by various ashes and high process temperatures. The ashes were obtained from the biomasses of mixed wood and oat straw, as well as from sewage sludge, by ashing. Long-term corrosion tests were carried out at 650 °C over a period of 1000 h. The chemical composition, mineral phases, and corrosion effects were studied by X-ray fluorescence (XRF), scanning electron microscopy equipped with energy-dispersive X-rays (SEM–EDX), and X-ray diffraction (XRD) from the surface and on the cross-section of the samples. The chemical composition of the ashes was quite different, but representative of their particular fuel. Together with the effects of the operating temperature and mass transfer, significant differences in the degree of the corrosion depth were detected for the various ashes. For the investigated samples, the corrosion mechanisms were inferred based on the identified corrosion products.

scholarly journals The Interface Microstructures and Mechanical Properties of Laser Additive Repaired Inconel 625 Alloy

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4416
Author(s):  
Yiyun Wei ◽  
Guomin Le ◽  
Qingdong Xu ◽  
Lei Yang ◽  
Ruiwen Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Tensile Properties ◽  
Dendritic Structure ◽  
Laves Phase ◽  
Inconel 625 ◽  
Second Phase ◽  
Equiaxed Crystal ◽  
Columnar Crystal ◽  
Inconel 625 Alloy ◽  
Deposition Thickness

The microstructure and micro-mechanics around the repaired interface, and the tensile properties of laser additive repaired (LARed) Inconel 625 alloy were investigated. The results showed that the microstructure around the repaired interface was divided into three zones: the substrate zone (SZ), the heat-affected zone (HAZ), and the repaired zone (RZ). The microstructure of the SZ had a typical equiaxed crystal structure, displaying simultaneously precipitated block-shaped MC-type carbides (NbC, TiC), with bimodal sizes of approximately 10 μm and 0.5 μm and an irregularly shaped flocculent Laves phase. Recrystallization occurred in the HAZ, and led to significant grain growth; a portion of the second phase dissolved in the original grain boundaries. In the RZ, there was a columnar crystal structure, and the size increased with increasing deposition thickness. Moreover, the microstructure between the layer interface and layer interior was quite different, presenting an overlapping transition zone (OTZ), in which the dendritic structure coarsened and more Laves phase were precipitated, compared to in the layer interior. The hardness and tensile properties of the LARed samples were equivalent to those of the wrought substrate, which indicates that laser additive repairing (LAR) is a reliable repair solution for damaged and mis-machined components comprising Inconel 625 alloy.

Effect of heat input on mechanical and microstructural properties of Inconel 625 depositions processed in wire arc additive manufacturing

2021 ◽  
pp. 095440892110047
Author(s):  
DT Sarathchandra ◽  
MJ Davidson
Keyword(s):  
Heat Input ◽  
Elevated Temperatures ◽  
Microstructural Characterization ◽  
Deposition Process ◽  
Columnar Structure ◽  
Inconel 625 ◽  
Cold Metal Transfer ◽  
Electron Microscopes ◽  
Cold Metal ◽  
Wire Arc Additive Manufacturing

Inconel 625 alloy resists corrosion, fatigue and wear at elevated temperatures and hence they are used in aerospace, chemical, petrochemical, marine, and other high-temperature applications. In the present study, single beads of Inconel 625 were deposited using the cold metal transfer (CMT) based wire arc deposition process. Seven heat input conditions were used to study the microstructure and mechanical characteristics. Microstructural characterization was done with optical and scanning electron microscopes while microhardness was measured using the Vickers microhardness testing method. It has been observed that the microstructure of the deposited beads consists of a columnar structure with primary dendrites. Also, intermetallic elements like Niobium (Nb), Molybdenum (Mo), and Laves were formed. It was also observed that the percentage of Nb and Mo increases with heat input. The microhardness increases with an increase in heat input and the maximum hardness was found to be 234.7 HV.

Sign in / Sign up

Export Citation Format

Share Document