Heat Treatment Of Welded Joints Research Articles

Heat treatment of welded joints of experimental highly-doped titanium alloy

In this article, the effect of heat treatment on the phase composition and structural state of welded joints of an experimental highly-doped titanium alloy, made by argon-arc and electron-beam welding, was investigated. As a result of the heat treatment of welded joints at a temperature of 690 ° C, the structure of the near-seam zone is stabilized. However, in order to fully restore the plasticity of the welded joint with the formation of alpha-phase globules of a simple structure in the structure of the near-seam zone, a higher heat treatment temperature is required.

FEATURES OF MICROSTRUCTURE FORMATION IN THE WELDED PIPE JOINTS DURING HIGH-FREQUENCY WELDING AND SUBSEQUENT LOCAL HEAT TREATMENT

The transience of heating and cooling processes during high-frequency welding (HFW) of pipes leads to the formation in the heat-affected zone (HAZ) of a coarse-grained strained bainitic and/or martensitic structure with high hardness. Local or volumetric heat treatment is used to correct the microstructure of the HAZ. The paper presents the results of a study of the structure and properties of welded pipe joints produced at the Vyksa Steel Works. It has been established that the microstructure of the welded joint of pipes made of low-carbon steels (not more than 0.07% C) is mainly bainite of lath morphology, and for steel with a high content of carbon (~0.3%) and manganese ‒ martensite. To estimate the temperature field in terms of the angle and thickness of the pipe wall during local heat treatment a finite element model was created. The paper shows that the use of the model made it possible to optimize the heating parameters during the local heat treatment of pipes of various sizes. The experiments on local heat treatment of pipes with a diameter of 325 mm, made from rolled products 8 mm thick of steel 09Г2С, showed a significant refinement of the initial microstructure of the HAZ, an increase in uniformity and the disappearanc of structural heat-affected zones. In medium carbon steels (~0.3% C) with a high manganese content, the thermal cycle of HFC welding leads to formation of martensite. The local heat treatment in the form of normalization does not allow one to exclude the formation of martensite in the segregation zones due to the high cooling rate. The local heat treatment of welded joints in pipes made of steel 30Г (Russian Standard) in the high tempering mode (650–700 °C), with preliminary cooling of the welded joint to a temperature below the completion of the martensitic transformation (in segregation zones ~50 °C), makes it possible to release the segregation martensite and form the microstructure of sorbitol there.

Modeling of the process of induction heat treatment of welded joints from rail high-strength steels

The Paton Welding Journal, 2021, №09. International Scientific-Technical and Production Journal «The Paton Welding Journal» «The Paton Welding Journal» has been published monthly since 2000 in English, ISSN 0957-798X. «The Paton Welding Journal» is a cover-to-cover English translation of the «Avtomaticheskaya Svarka» (Automatic Welding) journal. The «Avtomaticheskaya Svarka» journal has been published monthly since 1948 in Russian, ISSN 005-111X.

Technological, Microstructural and Strength Aspects of Welding and Post-Weld Heat Treatment of Martensitic, Wear-Resistant Hardox 600 Steel.

The study presents technological and structural aspects of production and heat treatment of welded joints of high-strength, abrasion-resistant Hardox 600 steel. As a result of the conducted research, it was found that the use of welding processes for joining this steel leads to the formation of a wide heat-affected zone, characterized by various structures favoring the reduction of abrasion resistance and deterioration of plastic properties, while increasing the susceptibility to brittle fracture. On the basis of the structural and strength characteristics, an effective welding technology for Hardox 600 steel was proposed, as well as the conditions and parameters of post-welding heat treatment, leading to obtaining structures close to a base material in the entire area of the welded joint. Despite the limited high-carbon equivalent CEV of the metallurgical weldability of the tested steel, the tests carried out in laboratory conditions allowed researchers to obtain welded joints characterized by very high strength indexes, corresponding to the base material, while maintaining satisfactory plastic and impact properties.

Переносний модуль для термічної обробки зварних стиків залізничних рейок

Переносний модуль для термічної обробки зварних стиків залізничних рейок

Portable module for heat treatment of welded joints of railway rails

Portable module for heat treatment of welded joints of railway rails

Подвійна термічна обробка зварних стиків залізничних рейок

Подвійна термічна обробка зварних стиків залізничних рейок

Effect of Heat Treatment on the Phase Composition and Corrosion Resistance of 321 SS Welded Joints Produced by a Defocused Laser Beam.

The effect of heat treatment of welded joints made of steel 321 on corrosion resistance, phase composition, residual stresses, and distribution of alloying elements was studied using optical microscope (OM) and scanning electron microscope (SEM), electron dispersive spectroscopy (EDS), X-ray diffraction (XRD), and intergranular corrosion testing (IGC). Samples previously obtained by the authors using defocused laser beam, which led to the formation of directionally crystallized austenite with lathy and skeletal δ-ferrite, were investigated. Based on X-ray diffraction studies in the base metal, the maximum number of peaks of various phases was presented, which decreased after exposure to the heating effect of the welding process and subsequent heat treatment. The distribution of alloying elements, in particular, Ti and Si, was significantly affected by heat treatment depending on the regimes. A spot chemical analysis showed that the nickel content differs in δ-ferrite and austenite by 1.5%–2% whereas the chromium content in these phases is not significantly different. Tests have shown that all samples have high resistance to intergranular corrosion, which can be explained by the insufficient dissolution of titanium carbides in austenite and the absence of chromium carbides formation along austenite grain boundaries, due to high cooling rates when welding by a defocused laser beam, and as a result, the high δ-ferrite content in which chromium dissolves.

ІННОВАЦІЇ ЯК ОСНОВНИЙ ВАЖІЛЬ СУБ'ЄКТА ГОСПОДАРЮВАННЯ В ПІДВИЩЕННІ ІНВЕСТИЦІЙНОЇ ПРИВАБЛИВОСТІ

The problem of increasing the investment activity of an enterprise is quite relevant, since in a developing economy, investment is a financial resource, on the basis of which enterprises can build their long-term strategic policy. The purpose of the research was to develop methodological, scientific-practical recommendations for assessing and increasing the investment attractiveness of a service enterprise, taking into account the impact of innovative implementations. The object of research. The article focuses on the innovation of the process equipment of the installation for automatic heat treatment of welded joints by conducting a comparative analysis of the possibilities available. The hypothesis of the research. The concept of the utility of investments may include the realization of investment goals that are different from the only possible behavior of an economic agent in the neoclassical theory of goal — maximizing profit or income. The methods used of the research were the practical side of the built relationship between the population and authorities at all levels. The statement of basic materials. The actual implementation of the obtained research results determines the novelty of the type of service on the Kazakhstan market, in particular, the city of Ust-Kamenogorsk and the East Kazakhstan region. In addition, the article recommends ways to improve the efficiency of the research object, allowing to obtain a significant economic effect and investment attractiveness of the business entity, the presented project is beneficial and expedient for implementation in the production process. The originality and practical significance of the research. The effectiveness of the project can be determined by calculating the net present value of the project, the profitability index and the payback period of the project. Conclusions. The payback period, taking into account discounting, is the period from the initial moment to the “payback time, including discounting.” The payback time with discounting is the earliest time in the billing period, after which the net present value of the investment becomes, and in the future remains non-negative.

Heat treatment of welded joints of high-strength railway rails (Review)

Heat treatment of welded joints of high-strength railway rails (Review)

Термическая обработка сварных соединений высокопрочных железнодорожных рельсов (Обзор)

Термическая обработка сварных соединений высокопрочных железнодорожных рельсов (Обзор)

Measurement of Ce/Ti Content in Austenitic Stainless Steel Welding Wire

Austenitic stainless steel (ASS) welding wire is a widely used filler metal for ferritic stainless steel (FSS). The microstructure of ASS is fine and it also has good weldability. However, the welded joints will appear hot cracks and dehisce under tensile force, and the grain boundaries will be corroded easily. In order to solve these problems, 14 kinds of Ce/Ti formulas are optimized by means of uniform test design and curve fitting. Then, the powders containing CeO2/TiO2 are added into the welded joints. After welding, a series of mechanical properties tests are conducted according to national standards. Then, the mechanical properties data are analyzed comprehensively by analyzing variance, boxplot as well as MATLAB 3D surface chart. The results show that sample 8 with the Ce/Ti amount of 0.24%/0.72% in ASS welding wire has better comprehensive mechanical properties. Compared with the samples without Ce/Ti, the yield strength, tensile strength, impact energy of normal temperature, and impact energy of heat treatment of welded joints increase by 127.2%, 41.9%, 841.8%, and 118.1% respectively.

Electron beam welding and heat treatment of welded joints of high-strength pseudo-β titanium alloy VT19

Electron beam welding and heat treatment of welded joints of high-strength pseudo-β titanium alloy VT19

Электронно-лучевая сварка и термообработка сварных соединений высокопрочного псевдо-β-титанового сплава ВТ19

Электронно-лучевая сварка и термообработка сварных соединений высокопрочного псевдо-β-титанового сплава ВТ19

On the problem of heat treatment of welded joints of railway rails

On the problem of heat treatment of welded joints of railway rails

К вопросу термической обработки сварных стыков железнодорожных рельсов

К вопросу термической обработки сварных стыков железнодорожных рельсов

Formation of Gradient Structures in the Zone of Joining a Deformable Nickel Alloy and a Single-Crystal Intermetallic Alloy during Thermodiffusion Pressure Welding and Subsequent Heat Treatment

The possibility of formation of a high-quality solid-phase joint of an Ni3Al-based single-crystal intermetallic VKNA-25 blade alloy with a high-temperature deformable EP975 disk alloy by pressure welding is studied to create high-performance one-piece blisk unit for the next-generation aviation gas turbine engines and to decrease the unit mass. The influence of the conditions of thermodiffusion pressure welding under the hightemperature superplasticity of the disk alloy and the influence of heat treatment of welded joints on the gradient structures in the welded joint zone and the structure at the periphery of the welded samples are investigated.

Индукционное устройство для термической обработки сварных стыков железнодорожных рельсов

Индукционное устройство для термической обработки сварных стыков железнодорожных рельсов

Induction device for heat treatment of welded joints of railway rails

Induction device for heat treatment of welded joints of railway rails

RESOURCE-SAVING TECHNOLOGY OF PRODUCTION OF WELDED VESSEL MADE OF REFRACTORY STEEL 15H5M

With, is technologically very complex and energy-intensive subsequent high temperature heat treatment of welded joints made of the apparatus. It is shown that the developed technology of welding with RTTS in automatic welding in shielding gases, welding wires austenitic heat-resistant steel 15H5M martensitic structural class allows to provide in the heat-affected zones (WJZ) obtaining bainite instead of martensite structure with high fracture toughness and at the same time homogeneous dispersion structure of austenitic weld metal. Due to the hardening of the austenite, avoiding excessive heating reduces the probability of formation of hot cracks austenit the seam, increases the corrosion resistance cracking, as when welding in layers,and the concomitant forced cooling adjustable. Thus by providing a compressed thermal cycles of welding, there occurs a reduction in the width of the active zones with a corresponding decrease in the values of residual welding stresses in the welded connection. Achieved greater generality of the grain boundaries of fine-grained bainitic ordered structure in the heat-affected areas of overheating of welded steel and the dispersed structure of the austenitic weld metal in the zone of fusion with minimal distortion of the microstructure in the fusion zone of the dissimilar joints. The introduction of the received results allows to improve technological and structural strength of welded joints, welding is used on the forced modes and to expand the scope of welding technology sabaliauskas heat-resistant steels without the use of heat treatment in the production of petrochemical equipment and pipelines, reduce the cost of welded equipment.(The purpose of developing resource-saving of technological process of manufacture of welded southwest of shielding gases in austenitic welding wires with high-temperature steel 15H5M regulation with the use of automatic welding thermal cycles (RTC). Technical and economic efficiency of the developed technological process of welding is ensured by eliminating preliminary and accompanying heating during welding to 250-350.