Special Issue "Welding Metallurgy"

A special issue of Metals (ISSN 2075-4701). This special issue belongs to the section "Welding and Joining".

Deadline for manuscript submissions: closed (31 July 2022) | Viewed by 5746

Special Issue Editor

Dr. Pasquale Russo Spena
E-Mail Website
Guest Editor
Department of Management and Production Engineering, Politecnico di Torino, Torino, Italy
Interests: advanced manufacturing processes; sheet forming; welding; mechanical joining; numerical modeling; process monitoring; aluminum and steel sheet; materials characterization; heat and surface treatments
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

A large number of research activities concerning the welding of metal alloys are ongoing in many industrial fields. The ability to effectively weld traditional and innovative metals is mainly driven by the metallurgical phenomena that are involved in the joining process. These are not fixed factors for a given metal but also depend on joint shape and welding techniques.

Therefore, an understanding of welding metallurgy and of the influence of the welding processes on weld microstructure, mechanical properties, and appearance (e.g., defects, distortions due to residual stresses) is crucial to guarantee the performance of assembled parts and structures during the service, in any field.

This Special Issue aims to collect the most recent research on innovative and pioneering works in welding metallurgy that cover several aspects such as microstructure–property relationships of welds, welding techniques (fusion welding and solid-state welding), residual stress and distortion, post-weld heat treatment, numerical simulation of weld solidification and cooling, as well as corrosion phenomena.

Dr. Pasquale Russo Spena
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Metals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • welding metallurgy
  • weldability
  • ferrous and non-ferrous alloys
  • fusion welding
  • solid-state welding
  • microstructure–mechanical property relationships
  • residual stress and distortion
  • post-weld heat treatment
  • modeling and FEM simulation
  • corrosion

Published Papers (7 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Article
A Study on the Development of an Optimization Algorithm and Determination Procedure for Toughness Deterioration Characteristics through Flux Core Arc Heat Input Control of ASTM A553-1 (9% Nickel Steel)
Metals 2022, 12(7), 1213; https://doi.org/10.3390/met12071213 - 18 Jul 2022
Viewed by 323
Abstract
The International Maritime Organization has adopted the reduction of carbon dioxide emissions from ships as an important priority, and is continuously strengthening its regulations on marine air pollution. By 2035, it is expected that LNG-powered ships will account for more than 50% of [...] Read more.
The International Maritime Organization has adopted the reduction of carbon dioxide emissions from ships as an important priority, and is continuously strengthening its regulations on marine air pollution. By 2035, it is expected that LNG-powered ships will account for more than 50% of the available ships. Accordingly, the demand for equipment related to LNG-fueled ships is expected to grow as well, requiring the development of a lot of equipment. However, the characteristics of LNG-powered ships mean that they require a high level of reliability and long history of operating reliably. Even when a product is developed, numerous demonstrations and quality assurance measures are needed to reach the technological level ship owners and customers require. Therefore, an optimization procedure to determine the welding quality for 9% Ni steel is necessary. In this study, the heat input criteria that induce brittle fracture characteristics were analyzed to optimize the flux core arc welding process for 9% Ni steel used in the manufacture of LNG storage tanks. We developed an optimization algorithm (Welding Current, Arc Voltage, Welding Speed) that can select a group of fracture conditions by examining the tendency of the tissue to brittle fracture due to excessive heat input among potential quality issues of cryogenic steel. Capable of selecting the range in which quality deterioration occurs, determining quality of a weld and avoiding the range in which toughness degradation occurs, through which a process to derive high quality 9% Ni welds is proposed. Full article
(This article belongs to the Special Issue Welding Metallurgy)
Show Figures

Figure 1

Article
A Study on Heat Input Control and a Quality Evaluation Algorithm to Prevent Toughness Deterioration of the Heat-Affected Zone in the Fiber Laser Welding Process of ASTM A553-1 (9% Nickel Steel) Material
Metals 2022, 12(7), 1195; https://doi.org/10.3390/met12071195 - 13 Jul 2022
Viewed by 316
Abstract
Various international organizations and governments of many countries are making efforts to prevent environmental pollution, with the IMO (International Maritime Organization) reinforcing related regulations. With these regulations, equipment related to LNG-fueled ships, which have the greatest carbon dioxide reduction effect among eco-friendly ships, [...] Read more.
Various international organizations and governments of many countries are making efforts to prevent environmental pollution, with the IMO (International Maritime Organization) reinforcing related regulations. With these regulations, equipment related to LNG-fueled ships, which have the greatest carbon dioxide reduction effect among eco-friendly ships, are expected to increase. Although the IGC code designates the materials that can be used for LNG containers, such as 304L stainless steel and 9% nickel steel, these materials have a tendency to deteriorate the tissue around the heat-affected zone due to excessive heat input. In this study, we analyzed the effect of brittle fracture in the weld zone and heat-affected zone after fiber laser welding and found that welding quality improved with control of the heat input. SVM discriminant analysis was applied to classify the groups in which brittle fracture and ductile fracture occurred. The shape of the penetration section, hardness in the welding zone and heat-affected zone, and fracture surface were selected as factors for discrimination; these values were determined under various welding conditions. With these data, we derived a regression model and multi-objective optimization algorithm to predict mechanical properties after welding, as well as the conditions necessary to prevent brittle fracture. Finally, the prediction models were verified, as the results of welding under the derived conditions were classified as ductile fracture group. Full article
(This article belongs to the Special Issue Welding Metallurgy)
Show Figures

Figure 1

Article
A Study on Determining Weld Joint Hardening and a Quality Evaluation Algorithm for 9% Nickel Weld Joints Using the Dilution Ratio of the Base Material in Fiber Laser Welding
Metals 2021, 11(8), 1308; https://doi.org/10.3390/met11081308 - 18 Aug 2021
Cited by 1 | Viewed by 646
Abstract
The demand for LNG-powered ships and related equipment is rapidly increasing among major domestic and foreign carriers due to the strengthened IMO regulations on the sulfur content of ship fuel oil. LNG operation in a cryogenic environment requires a storage tank and fuel [...] Read more.
The demand for LNG-powered ships and related equipment is rapidly increasing among major domestic and foreign carriers due to the strengthened IMO regulations on the sulfur content of ship fuel oil. LNG operation in a cryogenic environment requires a storage tank and fuel supply system that uses steel with excellent brittleness and fatigue strength. A ship using LNG is very sensitive to explosion and fire. For this reason, 9% Ni is often used, because ships require high quality products with special materials and structural technologies that ensure operability at cryogenic temperatures. However, research to derive uniform welding quality is urgent because the deterioration of weld quality in the 9% Ni steel welding process is caused by high process difficulty and differences in welding quality depending on a welder’s skill set. This study proposes a method to guarantee a uniform quality of 9% Ni steel in a fiber laser welding process by categorizing weld joint hardness according to the dilution ratio of a base material and establishing a standard for quantitative evaluation. Full article
(This article belongs to the Special Issue Welding Metallurgy)
Show Figures

Figure 1

Article
A Study on the Weldment Hardening Discrimination Procedure and Improvement of Flux Cored Arc Welding Process of ASTM A553-1 (9% Nickel Steel) Material Using Bead Geometry Distribution
Metals 2021, 11(8), 1282; https://doi.org/10.3390/met11081282 - 13 Aug 2021
Viewed by 555
Abstract
As a result of strengthened sulfur content standards for ship fuel oil in IMO regulations, major domestic and foreign carriers have a high and growing demand for liquefied natural gas (LNG) powered ships and related equipment. For LNG operation in a cryogenic environment, [...] Read more.
As a result of strengthened sulfur content standards for ship fuel oil in IMO regulations, major domestic and foreign carriers have a high and growing demand for liquefied natural gas (LNG) powered ships and related equipment. For LNG operation in a cryogenic environment, a storage tank and fuel supply system that uses steel with excellent brittleness and fatigue strength is required. Ships that use LNG have a high vulnerability to explosion and fire. For this reason, 9% Ni is typically used, since a ship requires high quality products with special materials and structural technologies that guarantee operability at cryogenic temperatures. However, there is an urgent need for research to derive a uniform welding quality, since high process difficulty and differences in welding quality related to a welder’s skills can cause a deterioration of the weld quality in the 9% Ni steel welding process. For 9% Ni steel, the higher the dilution ratio of the base metal, the lower the strength. In order to secure the required strength, excessive dilution of the base metal should be avoided, and the relationship between dilution ratio and strength should be investigated. According to previous research, if it exceeds 25% it may be lower than the API standard of 363 MPa for hardening welds. Therefore, in this study, the flux cored arc welding process is performed by establishing criteria that can be evaluated based on the SVM method in order to determine the structure of the weld to be cured according to the dilution rate of the base metal. We would like to propose a multipurpose optimization algorithm to ensure uniform quality of 9% Ni steel. Full article
(This article belongs to the Special Issue Welding Metallurgy)
Show Figures

Figure 1

Article
Experimental and Numerical Studies on Preparation of Thin AZ31B/AA5052 Composite Plates Using Improved Explosive Welding Technique
Metals 2020, 10(8), 1023; https://doi.org/10.3390/met10081023 - 30 Jul 2020
Cited by 3 | Viewed by 1069
Abstract
In this work, an improved explosive welding technique was investigated to fabricate a thin Mg/Al plate, where an additional thin aluminum sheet was used as a buffer layer between the explosive and the Al plate, and the Mg plate was rigidly constrained by [...] Read more.
In this work, an improved explosive welding technique was investigated to fabricate a thin Mg/Al plate, where an additional thin aluminum sheet was used as a buffer layer between the explosive and the Al plate, and the Mg plate was rigidly constrained by a steel plate to avoid excessive deformation. Moreover, the welding parameters were optimized using theoretical analysis and numerical simulation, and the interfacial behavior was simulated using the SPH method. The bonding properties of the achieved joints were investigated using microstructure observation and mechanical tests. It was concluded that this technique is an effective method for producing a thin Mg/Al composite plate. In both morphology observation and mechanical tests, an excellent bonding quality was confirmed. In addition, smoothed particle hydrodynamics (SPH) simulation revealed an extreme condition of local high temperature and plastic strain in the welding process, and the characteristic parameters of waves obtained using simulation are well congruous with the experiment. Full article
(This article belongs to the Special Issue Welding Metallurgy)
Show Figures

Figure 1

Article
Comparative Study of Droplet Transfer Modes on Appearance, Microstructure, and Mechanical Properties of Weld during Pulsed GMAW
Metals 2020, 10(5), 611; https://doi.org/10.3390/met10050611 - 08 May 2020
Cited by 9 | Viewed by 1185
Abstract
Droplet transfer plays a crucial role in welding stability and quality of pulsed gas metal arc weld (GMAW), referring to the process of heat and mass transition. In this work, the appearance, microstructure, microhardness, tensile properties, and impact toughness with three typical modes [...] Read more.
Droplet transfer plays a crucial role in welding stability and quality of pulsed gas metal arc weld (GMAW), referring to the process of heat and mass transition. In this work, the appearance, microstructure, microhardness, tensile properties, and impact toughness with three typical modes of droplet transfer in pulsed GMAW (ODMP: one drop per multiple pulses; ODPP: one drop per pulse; MDPP: multiple drops per pulse) were studied and compared. The results showed that the better welding appearance, the deeper penetration, and the less fume covered on the steel plate could be found during the ODPP welding process. At the same wire feeding speed and arc length, the average current was similar in ODPP and MDPP conditions. However, the average current in the ODMP condition was about 15 A larger than the other two, contributing to the higher heat input. Compared with MDPP and ODMP, the longest elongation and impact energy of the welded joint were found in the ODPP condition. Furthermore, the decrease of elongation and impact toughness in the ODMP condition might result from the higher heat input and the coarsen microstructure, like the proeutectoid ferrite and ferrite side plate. Full article
(This article belongs to the Special Issue Welding Metallurgy)
Show Figures

Figure 1

Review

Jump to: Research

Review
A Review on Laser-Assisted Joining of Aluminium Alloys to Other Metals
Metals 2021, 11(11), 1680; https://doi.org/10.3390/met11111680 - 21 Oct 2021
Cited by 5 | Viewed by 869
Abstract
Modern industry requires different advanced metallic alloys with specific properties since conventional steels cannot cover all requirements. Aluminium alloys are becoming more popular, due to their low weight, high corrosion resistance, and relatively high strength. They possess respectable electrical conductivity, and their application [...] Read more.
Modern industry requires different advanced metallic alloys with specific properties since conventional steels cannot cover all requirements. Aluminium alloys are becoming more popular, due to their low weight, high corrosion resistance, and relatively high strength. They possess respectable electrical conductivity, and their application extends to the energy sector. There is a high demand in joining aluminium alloys with other metals, such as steels, copper, and titanium. The joining of two or more metals is challenging, due to formation of the intermetallic compound (IMC) layer with excessive brittleness. High differences in the thermophysical properties cause distortions, cracking, improper dilution, and numerous weld imperfections, having an adverse effect on strength. Laser beam as a high concentration energy source is an alternative welding method for highly conductive metals, with significant improvement in productivity, compared to conventional joining processes. It may provide lower heat input and reduce the thickness of the IMC layer. The laser beam can be combined with arc-forming hybrid processes for wider control over thermal cycle. Apart from the IMC layer thickness, there are many other factors that have a strong effect on the weld integrity; their optimisation and innovation is a key to successfully delivering high-quality joints. Full article
(This article belongs to the Special Issue Welding Metallurgy)
Show Figures

Figure 1

Back to TopTop