scholarly journals Weldability of micro-alloyed high-strength pipeline steels using a new friction welding variant

2010 ◽  
Vol 1 (1) ◽  
pp. 94-101
Author(s):  
Koen Faes ◽  
Patrick De Baets ◽  
Alfred Dhooge ◽  
Wim De Waele ◽  
Rudi Denys ◽  
...  

An innovative welding method for fully automatic joining of pipelines has been developed. Theproposed welding procedure is a variant of the conventional friction welding process. A rotatingintermediate ring is used to generate heat necessary to realise the weld. The working principles of thewelding process are described. The weldability of the micro-alloyed high-strength pipeline steel API-5L X65is experimentally investigated. It was found that the new welding process is suitable for joining this material.When welding with a sufficiently low heat input, a high weld quality is obtained. Under these circumstancesthe weld strength, ductility and impact toughness are high and fulfil the requirements of the commonly usedstandard EN 12732 for joining pipes.

Author(s):  
Lige Tong ◽  
Qilan Kang ◽  
Li Wang ◽  
Yongli Sui ◽  
Shiwu Bai

Welding is a process for joining similar metals. Heat input and interpass temperature are important technical parameters that affect the welding temperature distribution field. 2D simulation of multi-pass compound groove of welding process for X80 pipeline steel is carried out by finite element software ANSYS, in which the distribution of T8/5 of welding filling layers is analyzed. The results show that the effect of heat input to T8/5 is significant. The T8/5 becomes longer with the increase of the heat input. Because of the obvious preheat influence of the preceding pass to the following, the T8/5 becomes longer with the increase of the weld pass quantity. When interpass temperature is equal to preheat temperature, the difference of the T8/5 on filling layer is tended to be insignificant. The T8/5 will be located within a reasonable range by choosing the appropriate heat input and interpass temperature.


Author(s):  
HaiYang Lei ◽  
YongBing Li ◽  
Blair E. Carlson ◽  
ZhongQin Lin

In order to meet the upcoming regulations on greenhouse gas emissions, aluminum use in the automotive industry is increasing. However, this increase is now seen as part of a multimaterial strategy. Consequently, dissimilar material joints are a reality, which poses significant challenges to conventional fusion joining processes. To address this issue, cold metal transfer (CMT) spot welding process was developed in the current study to join aluminum alloy AA6061-T6 as the top sheet to hot dip galvanized (HDG) advanced high strength steel (AHSS) DP590 as the bottom sheet. Three different welding modes, i.e., direct welding (DW) mode, plug welding (PW) mode, and edge plug welding (EPW) mode were proposed and investigated. The DW mode, having no predrilled hole in the aluminum top sheet, required concentrated heat input to melt through the Al top sheet and resulted in a severe tearing fracture, shrinkage voids, and uneven intermetallic compounds (IMC) layer along the faying surface, leading to poor joint properties. Welding with the predrilled hole, PW mode, required significantly less heat input and led to greatly reduced, albeit uneven, IMC layer thickness. However, it was found that the EPW mode could homogenize the welding heat input into the hole and thus produce the most stable welding process and best joint quality. This led to joints having an excellent joint morphology characterized by the thinnest IMC layer and consequently, best mechanical performance among the three modes.


Author(s):  
Ganesan S. Marimuthu ◽  
Per Thomas Moe ◽  
Bjarne Salberg ◽  
Junyan Liu ◽  
Henry Valberg ◽  
...  

Forge welding is an efficient welding method for tubular joints applicable in oil and gas industries due to its simplicity in carrying out the welding, absence of molten metal and filler metals, small heat-affected zone and high process flexibility. Prior to forging, the ends (bevels) of the joining tubes can be heated by torch or electromagnetic (EM) techniques, such as induction or high frequency resistance heating. The hot bevels are subsequently pressed together to establish the weld. The entire welding process can be completed within seconds and consistently produces superior quality joints of very high strength and adequate ductility. Industrial forge welding of tubes in the field is relatively expensive compared to laboratory testing. Moreover, at the initial stages of a new project sufficient quantities of pipe material may not be available for weldability testing. For these and several other reasons we have developed a highly efficient single station, solid state welding machine that carefully replicates the thermomechanical conditions of full-scale Shielded Active Gas Forge Welding Machines (SAG-FWM) for pipeline and casing applications. This representative laboratory machine can be used to weld tubular goods, perform material characterization and/or simulate welding and heat treatment procedures. The bevel shapes at mating ends of the tubes are optimized by ABAQUS® simulations to fine tune temperature distribution. The main aim of this paper is to establish a welding procedure for welding the tubular joints by the representative laboratory machine. The quality of the welded tubular joint was analyzed by macro/micro analyses, as well as hardness and bend tests. The challenges in optimizing the bevel shape and process parameters to weld high quality tubular joints are thoroughly discussed. Finally a welding procedure specification was established to weld the tubular joints in the representative laboratory machine.


2018 ◽  
Vol 937 ◽  
pp. 61-67
Author(s):  
Yu Jie Li ◽  
Jin Wei Lei ◽  
Xuan Wei Lei ◽  
Oleksandr Hress ◽  
Kai Ming Wu

Utilizing submerged arc welding under heat input 50 kJ/cm on 60 mm thick marine engineering structure plate F550, the effect of preheating and post welding heat treatment on the microstructure and impact toughness of coarse-grained heat-affected zone (CGHAZ) has been investigated. The original microstructure of the steel plate is tempered martensite. The yield and tensile strength is 610 and 660 MPa, respectively. The impact absorbed energy at low temperature (-60 °C) at transverse direction reaches about 230~270 J. Welding results show that the preheating at 100 °C did not have obvious influence on the microstructure and toughness; whereas the tempering at 600 °C for 2.5 h after welding could significantly reduce the amount of M-A components in the coarse-grained heat-affected zone and thus improved the low temperature impact toughness.


2021 ◽  
Vol 100 (09) ◽  
pp. 302-308
Author(s):  
BRANDON SCOTT TAYSOM ◽  
◽  
CARL D. SORENSEN ◽  
TRACY W. NELSON

Advanced manufacturing processes improve the cost and quality of goods. Rotary friction welding is a fast, energy-efficient, and reliable joining process for metals, but new applications are hindered by large development costs for each new alloy. Each alloy set has different welding characteristics; therefore, lessons learned from a single alloy are not always broadly applicable. To establish knowledge that is applicable across multiple alloys, a family of different superalloys were welded to discover process trends that were applicable beyond a single alloy set. In this study, weld symmetry did not correlate to weld strength across alloy systems. Some alloys’ strongest welds occurred at maximum symmetry, whereas high asymmetry was associated with different alloys’ maximum strength. High feed rates, high welding forces, low energy, and low temperatures all resulted in high-strength welds across all alloy and geometry combinations. Tensile strengths greater than 95% of base-metal strength were recorded for most alloy systems.


2021 ◽  
Vol 23 (3) ◽  
pp. 72-83
Author(s):  
Kirill Kalashnikov ◽  
◽  
Andrey Chumaevskii ◽  
Tatiana Kalashnikova ◽  
Aleksey Ivanov ◽  
...  

Introduction. Among the technologies for manufacturing rocket and aircraft bodies, marine vessels, and vehicles, currently, more and more attention is paid to the technology of friction stir welding (FSW). First of all, the use of this technology is necessary where it is required to produce fixed joints of high-strength aluminum alloys. In this case, special attention should be paid to welding thick-walled blanks, as fixed joints with a thickness of 30.0 mm or more are the target products in the rocket-space and aviation industries. At the same time, it is most prone to the formation of defects due to uneven heat distribution throughout the height of the blank. It can lead to a violation of the adhesive interaction between the weld metal and the tool and can even lead to a destruction of the welding tool. The purpose of this work is to reveal regularities of welding tool destruction depending on parameters of friction stir welding process of aluminum alloy AA5056 fixed joints with a thickness of 35.0 mm. Following research methods were used in the work: the obtaining of fixed joints was carried out by friction welding with mixing, the production of samples for research was carried out by electric erosion cutting, the study of samples was carried out using optical metallography methods. Results and discussion. As a result of performed studies, it is revealed that samples of aluminum alloy with a thickness of 35.0 mm have a heterogeneous structure through the height of weld. There are the tool shoulder effect zone and the pin effect zone, in which certain whirling of weld material caused by the presence of grooves on tool surface is distinctly distinguished. It is shown that the zone of shoulders effect is the most exposed to the formation of tunnel-type defects because of low loading force and high welding speeds. It is revealed that tool destruction occurs tangentially to the surface of the tool grooves due to the high tool load and high welding speeds.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ho Thi My Nu ◽  
Truyen The Le ◽  
Luu Phuong Minh ◽  
Nguyen Huu Loc

The selection of high-strength titanium alloys has an important role in increasing the performance of aerospace structures. Fabricated structures have a specific role in reducing the cost of these structures. However, conventional fusion welding of high-strength titanium alloys is generally conducive to poor mechanical properties. Friction welding is a potential method for intensifying the mechanical properties of suitable geometry components. In this paper, the rotary friction welding (RFW) method is used to study the feasibility of producing similar metal joints of high-strength titanium alloys. To predict the upset and temperature and identify the safe and suitable range of parameters, a thermomechanical model was developed. The upset predicted by the finite element simulations was compared with the upset obtained by the experimental results. The numerical results are consistent with the experimental results. Particularly, high upset rates due to generated power density and forging pressure overload that occurred during the welding process were investigated. The performances of the welded joints are evaluated by conducting microstructure studies and Vickers hardness at the joints. The titanium rotary friction welds achieve a higher tensile strength than the base material.


2019 ◽  
Vol 52 (2) ◽  
pp. 117-141
Author(s):  
K Mathiyazhagan ◽  
Krishna Kumar Singh ◽  
V Sivabharathi

Application of plastics is increasing day by day since plastics offer many distinct advantages as compared to metals. Plastics has mainly good thermal and electrical insulation properties, corrosion resistance, chemical inertness, and high strength to weight ratio. Additionally, these are cheaper in cost as compared to conventional materials. Plastics are additionally easy to process. Nowadays, product requirements are getting critical and thus product design is getting more complex in shape. To manufacture intricate complex shape creates complexity in manufacturing process which is sometimes very difficult or almost not feasible to produce with single manufacturing process. To manufacture such critical products, welding is a complimentary process. Type of weld joint and welding process can be selected based on the product design and load application on the product. Hot plate welding is very simple welding process as compared to other plastic welding process and most commonly used. Good quality weld is the prime objective of welding process. Weld strength is dependent on several parameters which may be process parameters as well as product parameters. The objective of this study is to identify the key parameters in hot plate welding process of the plastics using Decision Making Trial and Evaluation Laboratory which is one of the prioritization techniques. Results of the study focus on understanding the key parameters affecting the weld strength. Study shows that hot plate temperature, welding time, and melting time are the key parameters affecting the weld strength.


2019 ◽  
Vol 58 (1) ◽  
pp. 38-49 ◽  
Author(s):  
Francois Njock Bayock ◽  
Paul Kah ◽  
Belinga Mvola ◽  
Pavel Layus

Abstract Dissimilar welding offers exiting benefits for a wide range of engineering applications, such as automotive bodies, piping systems of nuclear power plants, health equipment. The main advantages of dissimilarwelding applications areweight reductions, lower costs, unique properties combinations, and improved energy-efficiency. The properties of dissimilar weld depend on the type of welding process used, the accuracy of the process parameters control, the characteristics of the base metal and the heat treatment procedures. The current study reviews the scientific literature on the topic of thermal analysis of dissimilar high-strength steels (HSS) welding. The review of experimental data was carried out to analyze the variable heat input effect on dissimilar welds. The results indicate the welds mechanical properties irregularity and reduction in toughness and tensile strength due to uneven changes in the microstructure. Furthermore, postweld heat treatment (PWHT) often resulted in the formation of intermetallic compounds whose properties are dependent on the duration of treatment. The research results can be used to optimize the heat input of the HSS welding process.


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