scholarly journals ANALYSIS OF WELD JOINT DEFORMATIONS BY OPTICAL 3D SCANNING

2016 ◽  
Vol 56 (1) ◽  
pp. 76 ◽  
Author(s):  
Jan Urminsky ◽  
Milan Marônek ◽  
Miroslav Jáňa ◽  
Ladislav Morovič

This paper presents an analysis of weld joint deformation using optical 3D scanning. The weld joints of bimetals were made by explosion welding (EXW). GOM ATOS II TripleScan SO MV320 equipment with measuring volume 320 × 240 × 240 mm, 5.0 MPix camera resolution and GOM ATOS I 350 with a measuring volume of 250 × 200 × 200 mm, 0.8 MPix camera resolution were used for experimental deformation measurements of weldments. The scanned samples were compared with reference specimens. The angular and transverse deformation were visualized by colour deviation maps. The maximum observed deformations of the weld joints ranged from −1.96 to +1.20 mm.

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1443 ◽  
Author(s):  
Maroš Vyskoč ◽  
Miroslav Sahul ◽  
Mária Dománková ◽  
Peter Jurči ◽  
Martin Sahul ◽  
...  

In this article, the effect of process parameters on the microstructure and mechanical properties of AW5083 aluminum alloy weld joints welded by a disk laser were studied. Butt welds were produced using 5087 (AlMg4.5MnZr) filler wire, with a diameter of 1.2 mm, and were protected from the ambient atmosphere by a mixture of argon and 30 vol.% of helium (Aluline He30). The widest weld joint (4.69 mm) and the highest tensile strength (309 MPa) were observed when a 30 L/min shielding gas flow rate was used. Conversely, the narrowest weld joint (4.15 mm) and the lowest tensile strength (160 MPa) were found when no shielding gas was used. The lowest average microhardness (55.4 HV0.1) was recorded when a 30 L/min shielding gas flow rate was used. The highest average microhardness (63.9 HV0.1) was observed when no shielding gas was used. In addition to the intermetallic compounds, β-Al3Mg2 and γ-Al12Mg17, in the inter-dendritic areas of the fusion zone (FZ), Al49Mg32, which has an irregular shape, was recorded. The application of the filler wire, which contains zirconium, resulted in grain refinement in the fusion zone. The protected weld joint was characterized by a ductile fracture in the base material (BM). A brittle fracture of the unshielded weld joint was caused by the presence of Al2O3 particles. The research results show that we achieved the optimal welding parameters, because no cracks and pores were present in the shielded weld metal (WM).


Author(s):  
Takuro Terajima ◽  
Takashi Hirano

As a counter measurement of intergranular stress corrosion cracking (IGSCC) in boiling water reactors, the induction heating stress improvement (IHSI) has been developed as a method to improve the stress factor, especially residual stresses in affected areas of pipe joint welds. In this method, a pipe is heated from the outside by an induction coil and cooled from the inside with water simultaneously. By thermal stresses to produce a temperature differential between the inner and outer pipe surfaces, the residual stress inside the pipe is improved compression. IHSI had been applied to weld joints of austenitic stainless steel pipes (P-8+P-8). However IHSI had not been applied to weld joints of nickel-chromium-iron alloy (P-43) and austenitic stainless steel (P-8). This weld joint (P-43+P-8) is used for instrumentation nozzles in nuclear power plants’ reactor pressure vessels. Therefore for the purpose of applying IHSI to this one, we studied the following. i) Investigation of IHSI conditions (Essential Variables); ii) Residual stresses after IHSI; iii) Mechanical properties after IHSI. This paper explains that IHSI is sufficiently effective in improvement of the residual stresses for this weld joint (P-43+P-8), and that IHSI does not cause negative effects by results of mechanical properties, and IHSI is verified concerning applying it to this kind of weld joint.


2000 ◽  
Vol 122 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Carl E. Jaske

Fatigue-strength-reduction factors (FSRFs) are used in the design of pressure vessels and piping subjected to cyclic loading. This paper reviews the background and basis of FSRFs that are used in the ASME Boiler and Pressure Vessel Code, focusing on weld joints in Class 1 nuclear pressure vessels and piping. The ASME Code definition of FSRF is presented. Use of the stress concentration factor (SCF) and stress indices are discussed. The types of welds used in ASME Code construction are reviewed. The effects of joint configuration, welding process, cyclic plasticity, dissimilar metal joints, residual stress, post-weld heat treatment, the nondestructive inspection performed, and metallurgical factors are discussed. The current status of weld FSRFs, including their development and application, are presented. Typical fatigue data for weldments are presented and compared with the ASME Code fatigue curves and used to illustrate the development of FSRF values from experimental information. Finally, a generic procedure for determining FSRFs is proposed and future work is recommended. The five objectives of this study were as follows: 1) to clarify the current procedures for determining values of fatigue-strength-reduction factors (FSRFs); 2) to collect relevant published data on weld-joint FSRFs; 3) to interpret existing data on weld-joint FSRFs; 4) to facilitate the development of a future database of FSRFs for weld joints; and 5) to facilitate the development of a standard procedure for determining the values of FSRFs for weld joints. The main focus is on weld joints in Class 1 nuclear pressure vessels and piping. [S0094-9930(00)02703-7]


2020 ◽  
Vol 8 (5) ◽  
pp. 5246-5251

Customary automated welding, basic in ventures, for example, car creation, gets unfeasible in enterprises that utilization unstructured assembling systems, for example, shipbuilding. This is expected to some extent to the size of the made frameworks and the size and areas of the weld. In these unstructured assembling conditions, the cutting edge for automated welding has generally comprised of a fixed-track framework with a mechanical welding carriage that works along the track. In any case, elective automated welding approaches that utilize advancements from the field of versatile mechanical autonomy are being sought after. One such model is the semiautonomous Versatile Robotic Welding System (MRWS). The MRWS is a lightweight versatile controller comprising of a two-degrees-of-opportunity portable stage and a threedegrees-of-opportunity burn controller. The MRWS is equipped for climbing ferrous surfaces by the utilization of changeless magnet tracks and situating the welding light along a weld joint. This framework is intended to automate the welding procedure for an assortment of weld joints with insignificant arrangement time. Arrangement comprises of putting the MRWS superficially to be welded and heading to the expected weld joint. So as to be used in a producing condition, such a framework must be confirmed for the welding procedure it is performing. This paper exhibits and confirms the MRWS as a legitimate other option for automated welding in unstructured situations. The confirmation procedure comprises of two parts: plan approval dependent on hypothetical investigation of the MRWS framework models to demonstrate the weld procedure necessities can be met, trailed by an exact confirmation dependent on AWS weld test particulars for a particular, normally utilized welding process. The plan approval centers around the two essential contrasts between the MRWS and demonstrated fixed-track motorized welding frameworks, burn movement control on a portable stage, and effect of the MRWS attractive feet on the weld process. The observational confirmation was performed on a vertical section weld on gentle steel with tough movement, 3G-PF


Author(s):  
Olga V. Fukina ◽  
Sergey S. Kokorev

The article grounds the necessity to develop innovation methods of finding mass of dry raw materials. Today serious problems can be faced in production in case it is needed to find the mass of materials stored in storehouses in bulk. The use of tabular values of material density and humidity can decrease the accuracy of results. Available methods of measuring volume and mass of dry materials, such as visual, theoretical calculation, mine-surveyor measurement, laser 2D-scanning, laser 3D-scanning, radiolocation and acoustic scanning were analyzed. Their advantages and disadvantages were shown. The scientific novelty of the work is connected with innovation, highly accurate, automated method of finding mass of dry hydroscopic materials having different density and humidity, which is based on using the equipment for laser 3D-scanning. The authors propose to measure density and humidity of material at different levels of clamp, which can improve the accuracy of results. The article provides calculations proving the efficiency of the method during stock-taking of material resources at the enterprise. The article pays special attention to problems of stock-taking and registration of shortages in accounting and taxation.


Author(s):  
Akihiro Mano ◽  
Yoshihito Yamaguchi ◽  
Jinya Katsuyama ◽  
Yinsheng Li

Abstract In the past few decades, the cracks because of stress corrosion cracking (SCC) have been detected in the dissimilar weld joints welded using nickel based alloy in piping system of boiling water reactors. Thus, the structural integrity assessment for such weld joints has become important. Nowadays, probabilistic fracture mechanics (PFM) analysis is recognized as a rational method for structural integrity assessment because it can consider inherent uncertainties of various influencing factors as probability distributions and quantitatively evaluate the failure probability of a cracked component. The Japan Atomic Energy Agency has developed a PFM analysis code PASCAL-SP for a probabilistic structural integrity assessment of weld joint in pipe in nuclear power plant. This study improves the analysis functions of PASCAL-SP for weld joint welded using nickel based alloy in boiling water reactor susceptible to SCC. As an analysis example of the improved version of PASCAL-SP, the failure probability of a weld joint is quantitatively evaluated. Furthermore, sensitivity analyses are conducted concerning the effect of leak detection and in-service inspection. From the analysis results, it is concluded that the improved version of PASCAL-SP is useful for structural integrity assessment.


2010 ◽  
Vol 139-141 ◽  
pp. 352-355 ◽  
Author(s):  
Tian Hui Zhang ◽  
Hong Cai Fu ◽  
Pei Jun Yan ◽  
Fang Wei Jin ◽  
Qiong Wang

Weldability analysis, metallographic experiments and mechanical property experiments were carried out on weld joint between B610CF and 16MnR steel using shielded metal arc welding method and mixed active-gas arc welding method. Weldability analysis shows that the weld joint has some tendency to cold crack, and preheat is needed before welding. Metallographic results show that there are ferrite and bainite in weld metal, and in heat-affected zone of B610CF side there are ferrite and bainite, on which there is much dispersed slight Fe3C, and in heat-affected zone of 16MnR side there are ferrite, pearlite. There is no quenching microstructure resulting in crack in weld joint. From mechanical property results, it can be concluded that the weld joints have excellent impact toughness at low temperature and the tensile strength and plasticity of weld joints is matched to the ones of 16MnR steel. So the welding parameters in this paper are appropriate to get qualified weld joints.


2013 ◽  
Vol 716 ◽  
pp. 355-359 ◽  
Author(s):  
Ling Yan Zhao ◽  
He Xue ◽  
Kang Jiao ◽  
Wei Tang

Primary loop recirculation (PLR) piping weld joints in light water reactor (LWR) environments are more susceptible to stress corrosion cracking (SCC). Limited experimental work also suggested the complicated material and mechanical property of the fusion zone and the heat affected zone (HAZ) especially in dissimilar weld joints might play an important role in promoting SCC growth. In our study, different from the former sandwich like weld joint, a model of continuous heterogeneity mechanical property was established, the effect of welded mechanical heterogeneity on the stress-strain field and J-integral along the crack fronts at different locations were simulated in an Alloy 182-A533B dissimilar weld joint by the elastic-plastic finite element method (EPFEM). The results indicate that the crack near the dividing line of base metal (BM) and HAZ has higher resistance to SCC. At the dividing line of HAZ and weld metal (WM), the crack is prone to propagate into the WM, and will present more complex crack morphology and behaviors.


Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Agus Sasmito ◽  
Mochammad Noer Ilman ◽  
Priyo Tri Iswanto ◽  
Rifai Muslih

In this work, rotary friction welding processes of dissimilar AA7075/AA5083 aluminium alloy rods with the diameter of 15 mm were performed at varying rotational speeds, typically 370 to 2500 rpm. The aim of this research is to improve mechanical properties, in particular, strength and fatigue performance of the weld joints. Several experiments including macro and microstructural examinations, Vickers microhardness measurements, tensile tests, fatigue tests and residual stress measurements were carried out. Results showed that at higher rotational speeds, typically 540 rpm or above, the dissimilar AA7075/AA5083 rotary friction weld joints revealed a static fracture in the AA5083 base metal side, indicating that the joint efficiency is more than 100%. It seemed that the best weld joint was achieved at the rotational speed of 1200 rpm, in which the friction heat was sufficient to form metallurgical bonding without causing excessive flash and burn-off. In such a condition, the fatigue strength of the weld joint was slightly higher than AA5083 base metal, but it was lower than AA7075 base metal. It was confirmed that the crack origin is observed at the interface followed by fatigue crack growth towards AA5083 side, and the growth of crack seemed to be controlled by microstructure and residual stress.


2021 ◽  
Vol 410 ◽  
pp. 366-371
Author(s):  
Igor N. Odintsev ◽  
Taras P. Plugatar ◽  
Andrey A. Apalkov

Residual welding stresses affect significantly the strength, durability, and performance of structures. Therefore, there is an urgent need for developing and implementing techniques and equipment that allow reliably estimating stresses in experiments. This paper considers some aspects of the joint implementation of electronic speckle pattern interferometry and the spot drilling technique to determine these characteristics under the field conditions. The results of determining the distribution of residual stresses in the weld joint areas of DN 850 pipes are given for various welding modes. The study results are of independent significance and herewith, demonstrate the efficiency of the equipment developed to solve similar problems.


Sign in / Sign up

Export Citation Format

Share Document