Properties Of Butt Joints Research Articles

Hybrid Welding (Laser-Electric Arc MAG) of High Yield Point Steel S960QL.

The article discusses the effect of the hybrid-welding process (laser–electric arc MAG Metal Active Gas) on the structure and properties of butt joints (having various thicknesses, i.e., 5 mm and 7 mm) made of steel S960QL. Welding tests were performed in the flat position (PA) and in the horizontal position (PC). Joints made of steel S960QL in the above-presented configuration are present in elements of crane structures (e.g., telescopic crane jibs). The welding tests involved the use of the G Mn4Ni1.5CrMo solid electrode wire and the Ar+18% CO2 shielding gas mixture (M21) (used in the MAG method). Non-destructive visual and radiographic tests did not reveal the presence of any welding imperfections in the joints. The welded joints obtained in the tests represented quality level B in accordance with the requirements of the ISO 12932 standard. Microscopic metallographic tests revealed that the heat-affected zone (HAZ) contained the coarse-grained martensitic structure resulting from the effect of the complex welding thermal cycle on the microstructure of the joints. Destructive tests revealed that the joints were characterised by tensile strength similar to that of the base material. The hybrid welding (laser–MAG) of steel S960QL enabled the obtainment of joints characterised by favourable plastic properties and impact energy exceeding 27 J. The tests revealed the possibility of making hybrid-welded joints satisfying the quality-related requirements specified in the ISO 15614-14 standard.

Structure Formation of Butt Joints Made of Aluminum Alloys to Ensure the Quality of Mechanical Engineering Products

The article discusses the problems of ensuring high-quality formation and normative properties of butt joints of the 1560M and 1980T1 (AMg6 and B48) aluminum alloys as applied to engineering. A method is proposed for joining materials by means of EBW using an electron beam sweep. Homogeneous and dissimilar joints have been investigated, heat treatment of joint from the 1980T1 alloy and a dissimilar joint from the 1560M + 1980T1 alloys is recommended. The paper also presents the results of mechanical properties testing, the corrosion resistance and the delayed fracture tests. A welding technology that makes it possible to obtain high-quality butt-welded joints from aluminum alloys in thicknesses up to 40 mm has been developed and implemented.

Effect of tool feed on mechanical properties of butt joints during friction welding with mixing of aluminum alloys

Friction stir welding of butt joints of aluminum alloys is considered. It is experimentally determined, that when temperature and time parameters are violated, defects in the form of discontinuities are localized at the boundary of the weld and the base metal, due to incompatibility of deformations of the weld metal and the adjacent base material. Keywords friction welding with stirring, aluminum alloy, mode parameters, structure, defects, strength. feofanov.fan1@yandex.ru

Uticaj brzine zavarivanja trenjem sa mešanjem na mehaničke karakteristike zavarenog spoja AA2024 T351 aluminijumske legure

The aim of this study is to analyze how the process parameters affect the mechanical properties of butt joints obtained by friction stir welding (FSW). The experimental study was performed by the FSW of sheets having a thickness equal to 6 mm and made of aluminum alloys AA2024 T351, varying the process parameters, namely rotational speed and welding speed. The following welding parameters were used: the rotation speed of the tool did not change and amounted to 750 rpm, and the welding speed was 73, 116,150 mm / min. The welds were obtained without the presence of errors and with an acceptable flat surface of the compound. Tensile tests were performed orthogonally to the welding direction on specimens having the welding nugget placed in the middle of gage length. Vickers hardness measurement was conducted perpendicular to the welding direction, a cross-section of the weld joint. The hardness profiles were obtained along 3 horizontal and 63 vertical directions. Bend testing was carried out according to EN 910 The bending specimens were tested using face and root side of the joint in tension.

Effect of parameters of arc, laser and hybrid methods of welding on structure and properties of butt joints of high-strength steel S460M

Effect of parameters of arc, laser and hybrid methods of welding on structure and properties of butt joints of high-strength steel S460M

Влияние параметров дугового, лазерного и гибридного способов сварки на структуру и свойства стыковых сварных соединений из высокопрочной стали S460M

Влияние параметров дугового, лазерного и гибридного способов сварки на структуру и свойства стыковых сварных соединений из высокопрочной стали S460M

Effect of energy input on the microstructure and properties of butt joints in DP1000 steel laser welding

This paper investigated the effect of energy input on the microstructure and properties of DP1000 steel butt joint using laser welding. As the energy input decreased, the weld bead width narrowed and the width of the softening zone became narrowed, and the mechanical properties increased as the energy input decreased. Demarcating different areas of the welded joint and testing the change in length due to the tensile tests indicated that only the HAZ of the welded joint had an apparent extension, the base metal and weld metal zone had no clear deformation, and the inharmonious deformation led to a significant decline in ductility of the entire welded joint. The HAZ hardness analysis of the welded joints revealed that apparent softening existed in the sub-critical and inter-critical zones of the HAZ.

Microstructures and mechanical properties in laser beam welds of titanium matrix composites

Laser beam welding (LBW) was used to 2 mm thick titanium matrix composites (TMCs) sheets and microstructure, hardness and tensile properties of butt joints were studied. Welded joints without defects were obtained indicating that LBW is a suitable processing method for TMCs. The results reveal that the fusion zone completely consists of α′ martensite causing an increase of more 27% in hardness compared with that of base metal. The heat affected zone consists of a mixture of α′ martensite and primary α phases. Large gradients of microstructures and hardness are found over the narrow heat affected zone dependent on the β-transus temperature during weld cooling. TiBw with smaller sizes redistribute at grain boundaries in the weld. The joints show excellent strength and they can reach the full strength compared with the base metal with sound welding parameters, which is ascribed to the presence of α′ martensite and refinement of TiBw in the weld.