scholarly journals Thermal and Residual Stress Distributions in Inconel 625 Butt-Welded Plates: Simulation and Experimental Validation

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Harinadh Vemanaboina ◽  
Edison Gundabattini ◽  
Kaushik Kumar ◽  
Paolo Ferro ◽  
B Sridhar Babu
Keyword(s):  
Residual Stress ◽  
Arc Welding ◽  
Thermomechanical Analysis ◽  
Numerical Code ◽  
Inconel 625 ◽  
Stress Distributions ◽  
X Ray Diffraction ◽  
Gas Tungsten Arc ◽  
Thermal Measurements ◽  
Gtaw Process

Thermal and residual stress distributions induced by the gas tungsten arc welding (GTAW) process on Inconel 625 were studied using numerical simulation and experiments. A multi-pass welding model was developed that uses a volumetric heat source. Thermomechanical analysis is carried out to assess the Thermal and residual stress distributions. Experiments were carried out with 5 mm thick Inconel 625 plates. X-ray diffraction techniques were used to measure residual stresses, and IR thermometry was employed to capture the temperature values on the welded joints. Simulations were performed with ANSYS numerical code, and a close agreement was found between the predicted and experimentally measured residual stress. Thermal measurements were collected pass by pass from the analysis, and the agreement was 9.08%. The agreement between the measured and analysed residual stress was 11%.

Microstructure Characteristics of Fe-xCr-C Hardfacing Alloys

2012 ◽  
Vol 472-475 ◽  
pp. 165-168
Author(s):  
Lin Zong ◽  
Zheng Jun Liu
Keyword(s):  
Solid Solution ◽  
Optical Microscopy ◽  
Arc Welding ◽  
Room Temperature ◽  
Gas Tungsten Arc Welding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Characteristics ◽  
Gas Tungsten Arc ◽  
Gtaw Process

A series of Fe-xCr-C hardfacing alloys were successfully fabricated on a substrate of 20g steel by gas tungsten arc welding (GTAW) process. These claddings were disigned to observe hypoeutectic, near-eutectic, and hypereutectic structures with various Cr3C2 and M7C3 carbides at room temperature. According to X-ray diffraction(XRD) and optical microscopy (OM), the hypoeutectic and eutectic composites include the Fe-Cr solid solution(α+A) and Cr3C2 carbides. Hypereutectic structures consist of α+A+M+M7C3 respectively. The cladding of hypereutectic microstructure with great amounts of primary M7C3 carbides had the highest hardness of the all conditions.

scholarly journals Arc Characteristics and Weld Bead Microstructure of Ti-6Al-4V Titanium Alloy in Ultra-high Frequency Pulse Gas Tungsten Arc Welding (UHFP-GTAW) Process

2020 ◽  
Vol 26 (4) ◽  
pp. 426-431
Author(s):  
Wei LI ◽  
Gaochong LV ◽  
Qiang WANG ◽  
Songtao HUANG
Keyword(s):  
Titanium Alloy ◽  
Fusion Zone ◽  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Weld Bead ◽  
Gas Tungsten Arc ◽  
Arc Characteristics ◽  
Arc Pressure ◽  
Gtaw Process ◽  
Gas Tungsten

To resolve the problem of grain coarsening occurring in the fusion zone and the heat-affected zone during conventional gas tungsten arc welding(C-GTAW) welded titanium alloy, which severely restricts the improvement of weld mechanical properties, welding experiments on Ti-6Al-4V titanium alloy by adopting ultra-high frequency pulse gas tungsten arc welding (UHFP-GTAW) technique were carried out to study arc characteristics and weld bead microstructure. Combined with image processing technique, arc shapes during welding process were observed by high-speed camera. Meanwhile the average arc pressure under various welding parameters were obtained by adopting pressure measuring equipment with high-precision. In addition, the metallographic samples of the weld cross section were prepared for observing weld bead geometry and microstructure of the fusion zone. The experimental results show that, compared with C-GTAW, UHFP-GTAW process provides larger arc energy density and higher proportion of arc core region to the whole arc area. Moreover, UHFP-GTAW process has the obviously effect on grain refinement, which can decrease the grain size of the fusion zone. The results also revealed that a significant increase of arc pressure while increasing pulse frequency of UHFP-GTAW, which could improve the depth-to-width ratio of weld beads.

Fatigue Life Variance Prediction Incorporating Residual Stress Scatter Induced by Super-Finishing Grinding Process

2009 ◽  
Vol 416 ◽  
pp. 45-50
Author(s):  
Guang Hui Lu ◽  
Xue Ping Zhang ◽  
Er Wei Gao
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Diffraction Method ◽  
Machining Process ◽  
Stress Distributions ◽  
X Ray Diffraction ◽  
Machining Processes ◽  
Surface Residual Stress ◽  
Bearing Rings ◽  
The Impact

It is well known that there is a lager deviation in the fatigue life of machined components even under nominally identical loading conditions. Understanding and controlling fatigue life variance are essential to enhance reliability. However, few research focus on the impact of machining processes on the fatigue life variance of machined components. In this study, surface residual stress distributions of bearing rings randomly selected from a production line by super-finishing grinding, are measured by X-ray diffraction method in cutting and feed direction, and its scatter is analyzed by statistical tools. Based on the variance prediction theories, build a simplified fatigue life variance prediction model incorporating the resultant residual stresses scatter induced by machining process. Based on the Basquin equation, the model is validated by experimental data published in literature. The predicted fatigue life agrees well with the experimental average fatigue life. Statistical analysis shows that the predicted variances of fatigue life are equal to those estimated from experimental fatigue life.

Effects of Rare Earth Y2O3 on the Microstructure and Wear Behaviors of Ti-6Al-4V Cladding with SiC

2018 ◽  
Vol 934 ◽  
pp. 89-94
Author(s):  
Yuan Ching Lin ◽  
Tzu Hsuan Wang
Keyword(s):  
Arc Welding ◽  
Wear Loss ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
Electron Probe Micro Analyzer ◽  
Gas Tungsten Arc ◽  
Ni Powder ◽  
Clad Layer ◽  
Pin On Disk

This study elucidates the effect of the percentage of Y2O3 on the microstructure and tribological performance of Ti-6Al-4V clad by SiC and Ni powder, using gas tungsten-arc welding (GTAW). The microhardness of the clad layer was measured using a Vickers hardness tester. The microstructure of the clad layer was analyzed using a scanning electron microscope (SEM) and an electron probe micro-analyzer (EPMA). X-ray diffraction (XRD) was used to determine the constituent phases of the clad layer. A pin-on-disk rotating tribometer was used to evaluate the wear resistance of the substrate and the clad layer. According to the experimental results, TiC and TiSi2 reinforcing phases were formed in situ in the clad layer during cladding process. The microhardness of the clad layer was two to three times that of the substrate, and the wear loss of the clad layer was about 51.5%~14.7% of that of the substrate. The optimal amount of Y2O3 enhanced the formation of TiC and TiSi2 and thus improved the microhardness of the clad layer. However, an amount of Y2O3 that over a critical value reduced the formation of reinforcing phases and degraded the mechanical properties of the clad layer.

In-Situ Neutron Diffraction Study of Gas Tungsten Arc Welding of a 1018 Plain Carbon Steel

2007 ◽  
Vol 1027 ◽  
Author(s):  
Michael Gharghouri ◽  
Michael J Watson ◽  
David Dye ◽  
Ronald B Rogge
Keyword(s):  
Neutron Diffraction ◽  
Arc Welding ◽  
Neutron Diffraction Study ◽  
Plain Carbon Steel ◽  
Gas Tungsten Arc Welding ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Gas Tungsten ◽  
In Situ Neutron Diffraction

AbstractIn-situ neutron diffraction measurements of a dynamic Gas Tungsten Arc Welding (GTAW) process have been performed using a unique instrument that establishes steady-state conditions by translating and rotating a cylindrical specimen past a stationary weld torch. The fixed neutron sampling volume is at a constant location with respect to the torch as new material is brought into the fusion zone. We present maps of lattice spacing and integrated intensity as a function of location about the weld torch, which provide insight into the temperature and phase distributions around the weld.

Transformation Temperatures and Welding Residual Stresses in Ferritic Steels

2007 ◽  
Author(s):  
J. A. Francis ◽  
H. J. Stone ◽  
S. Kundu ◽  
R. B. Rogge ◽  
H. K. D. H. Bhadeshia ◽  
...  
Keyword(s):  
Residual Stress ◽  
Arc Welding ◽  
Structural Integrity ◽  
Steel Plates ◽  
Stress Distributions ◽  
Metal Arc Welding ◽  
Thick Steel ◽  
Steel Welds ◽  
Welding Consumables ◽  
Filler Metals

Residual stress in the vicinity of a weld can have a large influence on structural integrity. Here the extent to which the martensite-start temperature of the weld filler metal can be adjusted to mitigate residual stress distributions in ferritic steel welds has been investigated. Three single-pass groove welds were deposited by manual-metal-arc welding on 12mm thick steel plates using filler metals designed to have different martensite-start temperatures. Their residual stress distributions were then characterised by neutron diffraction. It was found that a lower transformation temperature leads to a potentially less harmful stress distribution in and near the fusion zone. The experimental method is reported and the results are interpreted in the context of designing better welding consumables.

Improving Corrosion Resistance of AA2014 Welds with Micro Arc Oxidation

2013 ◽  
Vol 765 ◽  
pp. 634-638 ◽  
Author(s):  
Roshan Jacob ◽  
S.A. Srinivasan ◽  
K. Sivaprasad ◽  
V. Muthupandi
Keyword(s):  
Corrosion Resistance ◽  
Current Mode ◽  
Silicate Solution ◽  
The Other ◽  
X Ray Diffraction ◽  
Gas Tungsten Arc ◽  
Weld Metals ◽  
Full Penetration ◽  
Gtaw Process ◽  
Micro Arc Oxidation

Autogenous single pass full penetration welds of 2.8 mm thick AA 2014 plates were produced by un-pulsed and pulsed gas tungsten arc welding (GTAW) process. In pulsed current mode, two levels of pulsing viz., 3 and 6 Hz were employed. In order to improve the corrosion resistance of weld metals, micro arc oxidation (MAO) treatment was given in aqueous silicate solution containing either borax or tungstate. The MAO treatment was carried out for 10, 20 and 30 minutes. Irrespective of the electrolyte composition, surface roughness increased with increasing treatment duration. However, the effect was observed to be significant with borax addition. X-ray diffraction studies showed that γ-Al2O3 content in the coating continued to increase up to 20 minutes and for the coating produced with 30 minutes duration the α-Al2O3 content was found to be more than γ-Al2O3. The coating treated for 30 minutes exhibited relatively poorer corrosion resistance than the other coated specimens. The better corrosion resistance offered by the coating obtained after 20 minutes, compared with the other coatings, could be attributed to the nature of the oxide and its content. Even though tungstate addition improved hardness of the coating, borax addition was found to enhance the corrosion resistance.

scholarly journals Comparison of Measured Residual Stress Distributions in Extra-Thick Butt Welds Joined by One-Pass EGW and Multipass FCAW

2014 ◽  
Vol 6 ◽  
pp. 861247 ◽  
Author(s):  
Jeong-Ung Park ◽  
GyuBaek An ◽  
Wan Chuck Woo ◽  
Jae-hyouk Choi ◽  
Ninshu Ma
Keyword(s):  
Residual Stress ◽  
Arc Welding ◽  
Electron Gas ◽  
Diffraction Method ◽  
Stress Distributions ◽  
Flux Cored Arc Welding ◽  
Longitudinal Residual Stress ◽  
Inherent Strain ◽  
Inherent Strain Method ◽  
Neutron Diffraction Method

This study is to measure the welding residual stress distributions in a 70 mm-thick butt weld by one-pass electron gas welding using both the inherent strain method and neutron diffraction method, respectively. Based on the measurement results, the characteristics of residual stress distribution through thickness were compared between one-pass electron gas welding and multipass flux-cored arc welding. Residual stresses in the specimens of electron gas welding measured by the inherent strain method and neutron diffraction method were well matched. The longitudinal residual stress in the multi-pass flux-cored arc welding is tensile through all thicknesses in the welding fusion zone. Meanwhile, longitudinal residual stress in electron gas welding is tensile on both surfaces and compressive at the inside of the plate. The magnitude of residual stresses due to electron gas welding is lower than that due to flux-cored arc welding.

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