High Frequency Induction Welding Research Articles

Simulation of Temperature Field in High Frequency Induction Welding Process of Composite Aluminum Alloy Thin-Walled Tube

Welding temperature is the main factor that influences welding quality in high frequency induction welding process of composite aluminum alloy thin-walled tube. The finite element analysis software ANSYS is used to simulate temperature field. One complete penetration of thin-walled tube and boundary conditions of thermal calculation are taken into account. Then a linear thermal model is used to load and calculate to draw temperature distribution and thermal cycle curves of welding process. Research results provide corresponding theoretical basis for further analysis of welding stress and strain.

Effects of Surface Finishing on the Mechanical Properties of Induction Welded Iron Based Sintered Compacts*

Abstract In this study, iron based sintered parts were welded by high frequency induction welding. The effects of surface roughness on the mechanical properties of induction welded samples were investigated. Polished and unpolished samples were welded and mechanically tested by three point bending test. The hardness of the samples increased from the base material towards the weld metal. The weld metal, heat affected zone and the base material of the samples were investigated by light microscopy. In contrast to the polished samples, corrosion attack was registered in the welded region of unpolished samples. According to the results, the welding duration affects the mechanical properties. However, the surface finishing process was the dominant factor for the bending strength of the welded samples.

Ultra high frequency induction welding of powder metal compacts

The application of the iron based Powder Metal (PM) compacts in Ultra High Frequency Induction Welding (UHFIW) were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined.

The Residual Stress after High Frequency Induction Welding with Complex Shapes WC-Co Alloy and Steel

Residual stresses were investigation by Three-D finite element simulation and experimental method. The Three-D finite element simulation confirms large residual stress appears in seam zone because of the crack part and the maximum loading parts were not coinciding. The heating/cooling rate can seriously affect the residual stress. Along with the heating rate decrease, the residual stress reduces in material and had big drop in high heating rate range than lower range. And cooling rate influence the residual stress in cemented carbide was more sensitive than in steel. Meanwhile, far away the seam, the residual stress decrease and became stable. After heat treatment, the residual stress reduced from more than 800MPa, 300MPa to less 100MPa, 52Mpa in WC-Co side and steel side respectively and the material had better abrasion resistance and high strength.

Influence of Technology on Deformation Behavior of Cold-Formed High Frequency Induction Welded Steel Pipes

Tests were performed on mechanical property and microstructure of joints on cold-formed high frequency induction welded (HFIW) pipes. The welding surface energy (WSE) is proposed to evaluate the combined effect of technological parameters including the welding speed, input power and wall-thickness. The optimum production technology was obtained. The Widmanstätten microstructure and coarse grains were observed in the overheated zone. The width of the heat-affected zone (HAZ) is proportional to the WSE. With increase of the WSE, the reversed V-shape was formed by the mean bend angle. The optimum WSE decreases with decreasing the opening angle. Rather than the standard tensile test, the cold-bending test is suitable for evaluating effect of technology on quality of joints on cold-formed HFIW pipe.

Experimental Research on Structure and Performance of Joints in Cold-Rolled Rectangular Hollow Sections

The microstructure and mechanical behavior of welded joints under different technologies were compared for investigating the influence of technological parameters on microstructure and property of weld seam on thick-walled cold-rolled-forming high frequency induction welded (HFIW) tubes. The results show that microstructure of joints consists of a decarburized layer, an overheated area, a recrystallized zone and a partially-recrystallized zone. The opening angle and the welding surface energy (WSE) are important factors affecting microstructure and weld quality. The width of the heat-affected zone is proportional to the WSE. With increase of the WSE, the mean bend angle increases first and decrease later, showing a "mountain-peak" variation. The optimum WSE decreases with decrease of the opening angle because the smaller the opening angle is, the higher the heating efficiency is. The influence of processing parameter on the bending capability of joints is remarkable, while which on the impact toughness can be ignored.

Tackling the toughness of steel pipes produced by high frequency induction welding and heat-treatment

Steel linepipes produced by high frequency induction welding can result in a low-toughness zone at the weld junction, even after a heat treatment which reaustenitises the affected region. The possible causes for low toughness are explored, including microstructure, retained austenite, inclusions and crystallographic texture. It is found that the toughness is reduced primarily by the tendency for cleavage planes of ferrite crystals to align and hence create a macroscopic plane on which cleavage can propagate easily with little resistance from grain boundaries. This mechanism suggests that an appropriate heat treatment may alter the texture sufficiently to enhance the toughness of the zone concerned.

Improvements in flattening test performance in high frequency induction welded steel pipe mill

Areas of improvement in the acceptance criteria to the flattening test described in the pipe line international standards (API 5L and ISO 3183) are discussed. The aim is to make the flattening test acceptance criteria for the high frequency induction welded (HFIW) steel pipe clearly stated and defined so that there will be no argument about its interpretation. Recommendations for improving the mill set up to enhance the flattening test performance are also presented based on practical implementation in Saudi Steel Pipe Company. The process capability index is also used as quantitative tool to measure and monitor the performance of the flattening test using the height of the first weld crack as a basis of measurement.

Three Dimensional Analysis of High Frequency Induction Welding of Steel Pipes With Impeder

High frequency induction welding is widely employed for longitudinal seam welding of small scale tubes and pipes due to its relatively high processing speed and efficiency. This research is aimed at understanding the variables that affect the quality of the high frequency induction welding. The welding variables include the welding frequency, weld speed, vee angle, and tube thickness. Temperature distribution of the tube is calculated through three dimensional coupled electromagnetic and thermal finite element analysis. The skin and proximity effects are considered in the electromagnetic analysis. The influence of the impeder is also analyzed. The effects of the operating welding variables on the temperature distribution are investigated quantitatively by exhibiting the heat affected zone. The results explain the mechanism of significant enhancement of welding efficiency when the impeder is used. Not only good weld state can be obtained but also overheated edge can be avoided by understating the effect of welding variables. Suggestions are made for the better induction welding conditions.

Reduction of mouldboard plough share wear by a combination technique of hardfacing

This paper presents comparison of wear of regular mouldboard plough shares and two plough shares made of different basic materials, steel EN 10027 (HF-1) and EN 50Mn7 (HF-2), hardfaced by a combination of two welding processes, namely shielded metal arc welding (SMAW) and high-frequency induction welding (HFIW). Wear was determined by measurements of the changes of dimensions and weight during ploughing of sandy clay soil in Croatia. The dimensions and weight losses were lower for both types of hardfaced plough shares in comparison to regular shares, and lower fuel consumption and a higher rate of work were achieved with hardfaced plough shares. Hardfaced plough shares also offer lower production costs in comparison to regular plough shares. According to the overall results, this protection method can be recommended as an efficient solution for plough share wear protection.

고주파 유도용접 현상의 3차원 해석

High frequency induction welding is widely employed for longitudinal seam welding of small scale tubes and pipes because of its relatively high processing speed and efficiency. This research is aimed at understanding the variables that affect the quality of the high frequency induction welding. The welding variables include the welding frequency, weld speed, V-angle and tube thickness. Temperature distribution of the tube is calculated through three dimensional coupled electromagnetic and thermal FE analysis. The skin and proximity effects are considered in the electromagnetic analysis. The influence of the impeder is also analyzed. The effects of the operating welding variables on the temperature distribution are investigated quantitatively by exhibiting the heat affected zone (HAZ). The results explain the mechanism of significant enhancement of welding efficiency when the impeder is used. The proper welding conditions without the overheated edge are obtained through FE analysis.

High frequency induction welding simulating on ferritic stainless steels

This work aims to develop and evaluate a piece of equipment to simulate high frequency induction welding of ferritic stainless steels using a conventional power supply for resistance spot welding. Modifications were performed in the power supply to allow but welding of thin sheet and variation of process parameters like sheet width, welding time and current. Tests were performed to evaluate the use of this equipment. The results were evaluated by visual inspection, tensile testing and metallographic analysis. The analysis indicates that good-quality welds, which are similar to those obtained by high frequency welding, may be obtained.

The determination of heat treatment parameters of X52 microalloyed steel after high frequency induction welding

In metal manufacturing techniques such as casting, welding, cutting, deforming or powder metallurgy for the machine industry, a purposeful temporal change of temperature is a common practice. This temporal change of temperature, which is a function of a certain heat treatment, is the basis for a successful production and has great importance for the product quality. In this study, therefore, all the possible time temperature sequence was exercised with a small set of samples before the production was associated to the heat treatment applications and a simulation furnace was designed and assembled for this purpose. All the test results were discussed with respect to metallurgical and microstructural changing in the materials and the heat treatment simulations of the induction-welded pipes that are produced in pipe mills Mannesmann Sümerbank in Izmit – Turkey were accomplished.

Effects of Drawing Parameters on Mechanical Properties of BAS121 Alloy Tubes for Heat-Exchangers by High Frequency Induction Welding

The aim of this study is to investigate the optimum drawing parameter for BAS121 welded tubes. The BAS121 aluminium alloy tubes with 25 mm in external diameter and 1.3 mm in thickness for heat-exchangers were manufactured by high frequency induction welding with the V shaped convergence angle <TEX>$6.5^{\circ}$</TEX> and power input 55 kW. With increasing the reduction of area (<TEX>$13,\;21\%$</TEX>) by drawing, tensile strength was increased and elongation was decreased. With increasing the reduction of area by drawing, hardness in weld metal increased rapidly, while that of base metal increased slowly. In the specimen with the outer diameter smaller than 22 mm, hardness of weld metal was higher than that of base metal. The optimum drawing parameter of area reduction in BAS121 alloys was estimated about <TEX>$13\%$</TEX> because of the work hardening of welds.

High-frequency induction welding and subsequent block drawing – a way to produce copper–nickel tubes

High-frequency induction welding of cold-rolled strips to tubes combined with spinner-block drawing is a way of producing very long Cu–10Ni tubes. The results of such a production method are described. The tubes have good surface properties and dimensional tolerances and their mechanical properties and corrosion resistance are similar to those of standard tubes. Some examples of applications are given.

鋼管の高周波誘導溶接

鋼管の高周波誘導溶接

Study on weldability in high frequency induction welding (2nd Report)

The strength of welded parts under different welding conditions-required electric currency for welding and welding speed-was measured. It was found out that under any welding speed, the minimum amound of required currency shows the maximum welding efficiency and that the required currency decreases as the welding speed increases. It was also found that the width and strength of welded part is almost in proportional relation.

Study on weldability in high frequency induction welding (1st Report)

When Mg and Mn are added to 2S-Aluminium alloy, the electric conductivity of the metal is changed. And the critical amount of electric currency for welding varies in proportion to the electric conductivity of alloys.

Study on weldability in high frequency induction welding (3rd Report)

Study on weldability in high frequency induction welding (3rd Report)

Theoretical study of high frequency induction welding (1st Report)

Theoretical study of high frequency induction welding (1st Report)