scholarly journals Metallurgical and Mechanical Research on Dissimilar Electron Beam Welding of AISI 316L and AISI 4340

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
A. R. Sufizadeh ◽  
S. A. A. Akbari Mousavi

Dissimilar electron beam welding of 316L austenitic stainless steel and AISI 4340 low alloy high strength steel has been studied. Studies are focused on effect of beam current on weld geometry, optical and scanning electron microscopy, X-ray diffraction of the weld microstructures, and heat affected zone. The results showed that the increase of beam current led to increasing depths and widths of the welds. The optimum beam current was 2.8 mA which shows full penetration with minimum width. The cooling rates were calculated for optimum sample by measuring secondary dendrite arm space and the results show that high cooling rates lead to austenitic microstructure. Moreover, the metallography result shows the columnar and equiaxed austenitic microstructures in weld zone. A comparison of HAZ widths depicts the wider HAZ in the 316L side. The tensile tests results showed that the optimum sample fractured from base metal in AISI 316L side with the UTS values is much greater than the other samples. Moreover, the fractography study presents the weld cross sections with dimples resembling ductile fracture. The hardness results showed that the increase of the beam current led to the formation of a wide softening zone as HAZ in AISI 4340 side.

2010 ◽  
Vol 34-35 ◽  
pp. 1516-1520
Author(s):  
Hong Ye ◽  
Han Li Yang ◽  
Zhong Lin Yan

Electron beam welding process of AZ61 with 10mm thickness magnesium alloys was investigated. The influence of processing parameters including focusing current, welding beam current and welding speed was researched. The results show that an ideal weld bead can be formed by choosing processing parameters properly. Focusing current is main parameter that determines cross section shape. The beam current and welding speed are main parameters that determine the weld width and dimensions. The test results for typical welds indicate that the microhardness of the weld zone is better than that of the base meta1. A fine-grained weld region has been observed and no obvious heat-affected zone is found. The fusion zone mainly consists of small α-Mg phase and β-Mg17A112. The small grains and β phases in the joint are believed to play an important role in the increase of the strength of weld for AZ61 magnesium alloys.


2018 ◽  
Vol 7 (3.6) ◽  
pp. 198 ◽  
Author(s):  
R Ajith Raj ◽  
M Dev Anand

Aircraft industries witness an extensive variety of utilizations in unique welded joints thinking about the benefit of quality and high corrosion protection. In any case, joining of dissimilar materials is more mind boggling because of the distinction in material properties. In this investigation dissimilar metal joints of pure Copper plates and Stainless Steel 304 plates of 3mm thickness were welded with Electron Beam Welding. The welding input parameters like Welding speed, Beam current and Work distance liable to quality of weld are considered. Plan of analysis has been made utilizing Taguchi strategy with three levels of input values. Ultimate tensile strength and hardness number were found to decide the mechanical quality. Both the yield esteems are consolidated for expectation and optimized using Gray Relation Analysis (GRA). The impacts of the input parameters towards weld quality were analyzed using ANOVA. 


2013 ◽  
Vol 475-476 ◽  
pp. 1275-1279
Author(s):  
Qiang Zheng ◽  
Cheng Gang Yang ◽  
Yu He ◽  
He Chen ◽  
Ai Wu Yu

LY12 aluminum alloy was welded with vacuum electron beam welding, the effect of welding speed and electron beam current on the weld microstructure and mechanical properties of welding joints were studied, the results were shown that with the increasing of welding speed or decreasing of electron beam current, the grains in weld metal were refined, so the joint strength were increased. When the electron beam current was 18mA, the welding speed was 1000mm/min, the grains of weld metal were the finest, and the tensile strength was 373.2MPa. In addition, the micro-hardness of weld metal was much lower than base metal and heat affected zone, and the heat affected zone had certain softening phenomenon. With the increasing of welding speed or decreasing of electron beam current, the micro-hardness of weld metal was increased respectively.


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2233
Author(s):  
Tatyana Olshanskaya ◽  
Vladimir Belenkiy ◽  
Elena Fedoseeva ◽  
Elena Koleva ◽  
Dmitriy Trushnikov

The application of electron beam sweep makes it possible to carry out multifocal and multi-beam welding, as well as combine the welding process with local heating or subsequent heat treatment, which is important when preparing products from thermally-hardened materials. This paper presents a method of electron beam welding (EBW) with dynamic beam positioning and its experimental-calculation results regarding the formation of structures and properties of heat-resistant steel welded joints (grade of steel 20Cr3MoWV). The application of electron beam oscillations in welding makes it possible to change the shape and dimensions of welding pool. It also affects the crystallization and formation of a primary structure. It has been established that EBW with dynamic beam positioning increases the weld metal residence time and the thermal effect zone above the critical A3 point, increases cooling time and considerably reduces instantaneous cooling rates as compared to welding without beam sweep. Also, the difference between cooling rates in the depth of a welded joint considerably reduces the degree of structural non-uniformity. A bainitic–martensitic structure is formed in the weld metal and the thermal effect zone throughout the whole depth of fusion. As a result of this structure, the level of mechanical properties of a welded joint produced from EBW with dynamic electron beam positioning approaches that of parent metal to a greater extent than in the case of welding by a static beam. As a consequence, welding of heat-resistant steels reduces the degree of non-uniformity of mechanical properties in the depth of welded joints, as well as decreases the level of hardening of a welded joint in relation to parent metal.


Author(s):  
Liang Wang ◽  
Sergio D. Felicelli ◽  
Jacob Coleman ◽  
Rene Johnson ◽  
Karen M. B. Taminger ◽  
...  

Electron beam freeform fabrication (EBF3) is a process that uses an electron beam and wire feedstock to fabricate metallic parts inside a vacuum chamber. In this study, single and multiple layer linear deposits of AISI 316L stainless steel were produced with the EBF3 machine at NASA Langley Research Center (LaRC). EBF3 process parameters, including beam current, translation speed, and wire feed rate, were investigated in order to consider their effects on the resulting steel deposit geometry, microstructure and mechanical properties. Results indicate that the EBF3 process can produce pore-free, fully dense material within the range of process parameters used in this study. The electron beam deposited stainless steel has a solidification microstructure with fine columnar grains within most parts of the deposit due to the high cooling rate during the deposition, with some small homogeneous equiaxed grains at the top of the deposit. The mechanical properties of the deposits are comparable to those of wrought metal, which is attributed to the homogeneous fine-grained microstructure.


Author(s):  
Massab Junaid ◽  
Khalid Rahman ◽  
Fahd Nawaz Khan ◽  
Nabi Bakhsh ◽  
Mirza Nadeem Baig

Electron beam welding (EBW), pulsed Nd:YAG laser beam welding (P-LBW), and pulsed tungsten inert gas (P-TIG) welding of Ti–5Al–2.5Sn alloy were performed in order to prepare full penetration weldments. Owing to relatively high power density of EBW and LBW, the fusion zone width of EBW weldment was approximately equal to P-LBW weldment. The absence of shielding gas due to vacuum environment in EBW was beneficial to the joint quality (low oxide contents). However, less cooling rates were achieved compared to P-LBW as an increase in heat-affected zone width and partial α′ martensitic transformation in fusion zone were observed in EBW weldments. The microstructure in fusion zone in both the EBW and P-TIG weldments comprised of both acicular α and α′ martensite within the prior β grains. Hardness of the fusion zone in EBW was higher than the fusion zone of P-TIG but less than the fusion zone of P-LBW weldments due to the observed microstructural differences. Notch tensile specimen of P-LBW showed higher load capacity, ductility and absorbed energy as compared to P-TIG and EBW specimens due to the presence of high strength α′ martensite phase. Maximum sheet distortions and tensile residual stresses were observed in P-TIG weldments due to high overall heat input. The lowest residual stresses were found in P-LBW weldments, which were tensile in nature. This was owing to high power density and higher cooling rates in P-LBW operation. EBW weldment exhibited the highest compressive residual stresses due to which the service life of EBW weldment is expected to improve.


2014 ◽  
Vol 89 (7-8) ◽  
pp. 1605-1610 ◽  
Author(s):  
S.K. Albert ◽  
C.R. Das ◽  
Shiju Sam ◽  
P. Mastanaiah ◽  
M. Patel ◽  
...  

2021 ◽  
Vol 1160 ◽  
pp. 93-102
Author(s):  
Ajay Sharma ◽  
Sandeep Singh Sandhu ◽  
Vineet Kumar

Electron beam welding produces very narrow and deep penetration therefore it finds application where welding of thick materials is required. AISI 321 is susceptible to intergranular corrosion when it is used in high temperature and harsh conditions, owing to the Titanium depletion in the weld zone. However, the heat affected zone formed in electron beam welding extends to a narrow region across the weld pool. In the present study electron beam welding of austenitic 321 stainless steel is done to examine the mechanical and metallurgical properties of the joints. Microhardness tests along and across the weld bead were carried out. Tensile and impact tests were performed to analyze mechanical properties. The microstructures of the weld zone, fusion zone and base metals were also captured. Skeletal ferrites were seen in the weld metal. The aging treatment of 700°C for 24 hours which resulted in a change in morphology of the grains from skeletal to vermicular and promoted the formation of Ti-rich carbides on the grain boundaries. The maximum impact toughness at sub-zero temperature i.e. -40°C was recorded as 129.3 J in as-welded samples and it got reduced to 119.5 J after aging treatment. The average ultimate tensile strength was 582 N/mm2 and it got decreased to 481 N/mm2 after aging treatment.


1977 ◽  
Vol 99 (2) ◽  
pp. 323-326 ◽  
Author(s):  
M. S. Phadke ◽  
A. M. Joglekar ◽  
S. M. Wu

The spiking phenomenon in electron beam welding is characterized using the second-order continuous autoregressive model. The model parameters are then physically interpreted in terms of the random fluctuation in the beam power and the diffusion of heat energy in the plates being welded; and a mechanistic model is proposed for the spiking phenomenon. Finally, regression models are obtained to relate the spiking behavior to the accelerating voltage, the beam current, and the welding speed.


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