International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The paper presents the results of an investigation aimed at analysing the current state of the art in the construction of hot water piping systems. Weld joint analysis and evaluation is an essential part of the inspection of hot water pipelines to ensure their safe operation. The practical part of this work is focused on the analysis and evaluation of the weld joint of original and new hot water piping. Destructive and non-destructive weld joint testing methods were applied to carry out the evaluation and analysis, the results of which were used to compare the welded joints on the hot water pipeline

This paper presents an overview of technologies for joining fibre-reinforced polymer composites to thin-walled metal sheets. It covers the areas of welding, bonding with different surface texturing as well as mechanical joining. It analyses the problems arising from the different mechanical, physical properties of metals and composite materials and presents the possibilities of solving them by the application of individual and combined joining technologies.

As global environmental impacts have increased, modern societies have expressed a strong interest in implementing sustainable solutions to reduce emissions and use operational energy and natural resources. The construction industry is a leading promoter of significant environmental impacts because it consumes a significant amount of water, energy, and materials. Steel and welding are critical in all three major sectors of the industry: construction, infrastructure, and industry. This paper discusses the significance of meeting sustainable development goals in welded structures and identifies ways that this industry can help to reduce environmental impact and improve employment conditions while achieving economic growth, saving time, and maintaining structural quality. The paper discusses how to optimize various aspects ranging from raw material extraction to construction waste disposal using the life cycle assessment (LCA) methodology. It provides a starting point and demonstrates how these tools can contribute to more sustainable welded structures.

In this paper is reviewed google search as a helpful free instrument for statistics when preparing the state of art. It is applied to research in welding positions in the welding processes.

The paper focuses on the evaluation of the quality of fillet welds produced robotically by the method of impulse synergic welding MAG. This welding technology is used in the automotive industry in the production of rear seat backs for passenger cars. In the process of automated production, the speed of the process, accuracy, and quality of the made joints are important. Several factors affect the accuracy and quality of welded joints. The paper presents the results of research where the influence of filleting of fillet welds on their quality was confirmed. Visual and capillary methods were used to determine the quality of welds, metallographic analysis for evaluation depth of weld root penetration, strength properties of welds were evaluated by static tensile test. Statistical ANOVA methods were used to process the obtained values. Experimental work confirmed that the depth of welding of the weld root into the base material has the greatest influence on the final quality of fillet welds. It is this parameter that results in the elimination of the weld and thus the entire produ ct.

In this paper is reviewed google search as a helpful free instrument for statistics when preparing the state of art. It is applied to welding processes.

Welding is a manufacturing process, which uses heat or pressure to form a homogeneous weld when joining homogeneous or heterogeneous metal materials or thermoplastics. The last decade has been characterized by the intensive development of unconventional welding processes, which use friction as an energy source, and in developed countries have taken primacy over conventional welding processes. The modern welding process, known as Friction Stir Welding (FSW), offers many advantages over conventional Tungsten Inert Gas (TIG) and Metal Inert Gas (MIG) processes, both in terms of weld quality and environmental protection and in terms of saving time and materials needed to perform quality welding. This paper presents TIG, MIG and FSW welding technologies, with all the advantages and disadvantages, and the possibilities of their application in welding AA6082-T6 aluminum alloy (6xxx series), characterized by medium strength and outstanding corrosion resistance

The main task of the research is to establish the regularities of the formation of a non-detachable compound of thin-walled elements from the Ni-20Cr-6Al-1Ti-1Y2O3 alloy and to determine the functional condition of the influence of soldering modes on the physical-mechanical characteristics of the compound. It has been shown the modeling of temperature fields in ANSYS 18.1. It has been established that the process of vacuum soldering should take place at a temperature of 1350°C for 15-20 min; the strength of the resulting compound is 390-420 MPa when the sample is stretched. The obtained information can be used as a theoretical basis for the development of the manufacturing process of the elements of the spaceship heat-shielding system.

The main task of the research is to establish the regularities of the formation of a non-detachable compound of thin-walled elements from the Ni-20Cr-6Al-1Ti-1Y2O3 alloy and to determine the functional condition of the influence of soldering modes on the physical-mechanical characteristics of the compound. It has been shown the modeling of temperature fields in ANSYS 18.1. It has been established that the process of vacuum soldering should take place at a temperature of 1350°C for 15-20 min; the strength of the resulting compound is 390-420 MPa when the sample is stretched. The obtained information can be used as a theoretical basis for the development of the manufacturing process of the elements of the spaceship heat-shielding system.

In this research work the Welding technology that implements high frequency contact welding process (HFCW), is presented as a method for automatic steel pipes production. The pipes produced by the HFCW are meant to be used for natural gas transportation.
X60M steel coils with thickness of 6.5 mm are used as a raw material. The outer pipe diameter is φ508 and the length is 12000 mm. The preliminary welding procedure is based on the personal experience, technical knowledge and the expert judgment. A special attention has been paid to the most important welding parameters such as: current frequency, voltage and welding speed. After the welding was finished, an additional heat treatment (normalization) of the welded pipes (joints) was performed at the temperature of 900^oC.

In order to justify the proposed welding technology a complex analysis is applied. The first analysis was the chemical analysis of base metal. The next was the nondestructive testing consisted of a visual inspection, and ultrasound testing of the pipes. The destructive testing was consisted of tensile testing, bend testing and the hardness measurement. Besides the analysis of the micro and macro structure of the welded joints, a metallographic analysis is performed as well. Moreover a hydrostatic test and a flattening test were performed as an integral part of the entire testing process. The test results confirmed that the pipes produced with the predicted welding parameters completely fulfilled standard requirements. The manufacturing process for the pipes for natural gas transportation is ready to begin.

This paper describes the design and practical implementation of AC/DC/DC converter in mode of arc welding. An analysis of the operation of AC/DC/DC converter and its input/output characteristics are determined with computer simulations. The practical part is con- sisted of AC/DC/DC converter prototype for arc welding with output power of 3 kW and switching frequency of 64 kHz. The operation of AC/DC/DC converter is validated with experimental measurements.

Thermography measurements allow to detect the defects that may appear on a joint at welding of components. Energy pulse generated by a xenon lamp with adequate power in a short period of time is sufficient for thermal excitation and enables to register the temperature distribution using the thermography high resolution camera FLIR SC7000. The impulse with 6kJ energy and 6ms time generate sufficient power to measure the temperature distribution on the surface of the weld tested. During cooling the temperature of the area with defect changes more slowly than in the areas without defects, because of to the less intense heat dissipation. This allows the registration of defects in welds "on-line" at the production process. Material used for analysis detection of defects in the welded joints is Inconel 718, stainless steel 410 and stainless steel 321. The peak energy which flow throw the samples with defects in the welded joints its completely or partially blocked. It cause different temperature distribution on the surface in the places where the connection discontinuity take place.