Behavior of Transverse Fillet Welds: Experimental Program

Mechanical behavior of transverse fillet welded joints of high strength steel using digital image correlation techniques

Cyclic performance of flange-plate connection to box column with finger shaped plate

Residual shearing strength of fillet weld connections after exposure to elevated temperature

As flux cored wires for gas metal arc welding offer several technical and economic advantages they are becoming more and more popular. Matching flux cored wires for welding P92 have already been available for several years. A matching flux cored wire for welding the Co-alloyed cast steel CB2, which is used for turbine and valve casings operating at steam temperatures of up to 620°C, was developed recently. To connect casings with P92 pipes, dissimilar welding of CB2 to P92 is necessary. This can be done with filler metal that matches either CB2 or P92. Pre-tests have confirmed that flux cored arc welding (FCAW) can generally be used for dissimilar joint welding of CB2 to P92. To evaluate creep rupture strength dissimilar welds were performed with filler metal matching CB2 and P92, respectively. TIG welding was used for the root and the second pass and FCAW for the intermediate and final passes. Cross-weld tensile tests, side bend tests and impact tests of weld metals and heat-affected zones were carried out at ambient temperatures after two post-weld heat treatments (PWHT), each at 730°C for 12 hours. Creep rupture tests of cross-weld samples were performed at 625°C. This study compares the results of the mechanical tests at ambient temperature and the creep rupture tests, and discusses why P92 filler metals are preferred for such welds.

In the flux-cored arc welding (FCAW) process, the heat for welding is produced by an electric arc between a continuous filler metal electrode and a workpiece. This article discusses the advantages and disadvantages and applications of the FCAW process. It schematically illustrates the semiautomatic FCAW equipment used in the gas-shielded FCAW process. The article discusses the manufacture of flux-cored electrodes and the classification of electrodes, such as carbon and low-alloy steel electrodes, stainless steel electrodes, and nickel-base electrodes. The functions of common core ingredients in FCAW electrodes are listed in a table.

FCAW process to avoid the use of post weld heat treatment

This publication covers experimental investigations on the design resistance of arc-brazed fillet welds (CuAl7) on low-alloyed structural steel (S355) subject to predominantly static loading and regarding steel construction regulations (Eurocode). In current steel construction regulations, there is no standardized design approach for arc-brazed fillet welds available, so arc-brazed connections are rarely used despite the benefits they offer in several regards compared to conventionally welded connections. Therefore, a resistance model for arc-brazed fillet welds was calibrated based on tensile tests that were conducted on gas metal arc-brazed specimens with transverse and longitudinal fillet welds. Based on the statistical evaluation of the test results according to Annex D of EN 1990, a newly determined correlation factor βb is proposed, which can be used for the static design of arc-brazed fillet welds made of CuAl7. This approach leads to a significantly higher calculated design resistance than previous non-standardized design approaches allowed. Also, it was found that the failure behavior of the fillet welds is critical for the design resistance of the joints and that there is a need for further investigations with regard to a targeted joint failure, which, analogous to welded fillet welds, should take place along the throat of the weld and not along the less resistant diffusion zone of the joint. Thus, the results underscore the potential for the use of arc-brazed connections in steel construction in regard to their load-bearing capacity, but also highlight the necessity of continued research regarding factors influencing their structural integrity.

The capacity of each connector type in a shear-splice type of joint is reflected by its shear strength and shear deformation characteristics. When two or more types of fasteners share the load, it is clear that it is not satisfactory to simply combine the ultimate strength of each individual fastener type. Each of the different fastening elements has a different ductility and, in general, each reaches its ultimate strength at a different value of overall connection deformation. The strength of joints that combine bolts and fillet welds that act in the same shear plane has been examined. The study has shown that the rules provided in the AISC LRFD Specification do not adequately reflect the actual strength of this type of joint. Using test results from the University of Alberta and others, expressions are presented for the capacity of the various elements that make up a bolted-welded joint. These expressions enable the capacity of a combined bolted-welded joint to be predicted with a reasonable degree of accuracy. The examination showed that transverse fillet welds do not work well in combination with bolts because of the limited ductility of the former.

Fatigue strength of rolled JIS SM50A beams

The operation of the track rollers is dependent on the frictional forces between the rollers and the track. Furthermore, the presence of moisture-laden sand and mud in the surrounding environment accelerates the corrosion process, leading to a synergistic effect on abrasion wear. The production of new rollers is a highly energy-intensive process, resulting in the emission of significant quantities of carbon dioxide. The main objective of this research was to develop a process for remanufacturing track rollers by integrating hardfacing methods, specifically, combining buttering with gas-metal-arc welding (GMAW) that utilizes 309LMo and flux-core arc welding (FCAW) employing TiC-O. During the GMAW process, currents of 180 A, 220 A, and 260 A were applied at the same time as wire with a diameter of 1.2 mm, whereas the FCAW process involved using currents of 200 A, 250 A, and 300 A in conjunction with a wire with a diameter of 1.6 mm. An evaluation was conducted through mechanical tests and metallurgical analysis to determine the effect of the variable current on the physical and mechanical properties of the hardfill layer. Mechanical tests using the Rockwell method and metallurgical analysis via morphological observation were conducted to assess the performance of the remanufactured track roller. The outcomes revealed that as the current increase in GMAW/FCAW welding, the hardfacing layer became increasingly stiffer, but this effect was offset by the failure of the hardfacing interface to bond correctly, as shown by its insufficient fusion and the formation of cracks and holes that penetrated into the base metal. This study highlights the importance of welding parameters to achieve a balance between hardness in the base and weld metals, diffusion, and the quality of the bond between the two, as a practical and cost-efficient method for the remanufacturing industry.

The variant of gas metal arc welding (GMAW) with flux-cored wire is becoming popular in industry and shipyard due to its economy, higher operating current range and better weld quality. Welding of component needs to establish the optimum parameters for obtaining acceptable weld quality with maximizing penetration and minimizing the bead width and reinforcement. In present work, welding investigation is carried out with flux-cored arc welding (FCAW) process on AISI 201LN stainless steel, employing the central composite design (CCD) DoE. The FCAW process uses 100% CO2 as a shielding gas with flux-cored wire combination which is much economical shielding gas compared to widely used Ar+CO2 for stainless welding. Wire feed rate (WFR), voltage (V), welding speed (S) and nozzle to work distance (NTD) are considered as weld parameters to investigate the performance of weld bead viz., penetration (P), width (W) reinforcement (R), weld penetration shape factor (WPSF), weld reinforcement form factor (WRFF). The full quadratic models are developed using response surface methodology (RSM) showing good correlations with an average error percentage of 4.41 as minimum for P and maximum as 7.73 for WPSF. WFR, V and NTD are found significant parameters on performance characteristics. The optimization of all responses are performed using desirability analysis and results shows an acceptable composite desirability of 0.6674.

Flux cored arc welding has emerged as a vital welding technology in the realm of pipes and petrochemical pipelines, addressing the severe weld quality, material compatibility, and safety criteria in these essential applications. The paper begins with a brief description of the flux cored arc welding process, explaining its procedural complexities, the necessary tools used, and the variety of consumables used. The review then describes the complexities of flux cored arc welding's applicability in joining pipes due to the unique welding demands imposed by petrochemical pipelines. A thorough examination of flux cored arc welding characteristics and processes follows, identifying the critical welding parameters that have a significant impact on the structural strength and durability of flux cored arc welded joints. The review goes further to highlight key applications of flux cored arc welding through case studies by illustrating the adaptability of the welding procedure to different scenarios. An in‐depth analysis of flux cored arc welding technological advancements that highlights the current developments in electrode composition, shielding gases, and automation is also considered. In conclusion, this study offers a thorough overview of flux cored arc welding uses in pipes and petrochemical pipelines, fusing technical clarification with real‐world applications.

The thickness of steel plates used for large structures has been increasing with the rapid increase in the size of welding structures. The growing capacity of large-scale ships, such as container ships, has led to an increase in the thickness and strength of steel plates for shipbuilding. The steel plate toughness and resistance to brittle fractures tend to decrease for thick plates because of the so-called thickness effect. This study uses 80-mm-thick steel plates and two welding processes (i.e., flux cored arc welding process and electron gas welding process) to produce full-thickness weld joints. The welding residual stress in both welded joints is measured to evaluate the brittle crack propagation path. This study aims to investigate the effect of welding variables on the crack arrest toughness and crack propagation path of thick steel-plate welds. The thick steel plate has a high possibility in brittle fracture. A quantitative analysis is conducted through a temperature-gradient ESSO test to clarify the effect of the welding variables on the flux cored arc welding and electron gas welding process joints of steel plates with 50 and 80 mm thicknesses. The welding residual stress is also measured to evaluate the welding residual stress effect in both welding processes on the brittle crack propagation path using a neutron science analysis.

The Effect of Flux Core Arc Welding (FCAW) Processes On Different Parameters

WELD METAL CHARPY - CTOD CORRELATIONS FOR COLD MARINE APPLICATION