Submit to Materials Review for Materials Propose a Special Issue

Journal Menu

Journal Browser

Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Manufacturing Processes and Systems".

Deadline for manuscript submissions: closed (10 April 2022) | Viewed by 20444

Share This Special Issue

Special Issue Editor

Dr. Paolo Ferro

E-Mail Website
Guest Editor

Department of Engineering and Management, University of Padova, Stradella San Nicola 3, 36100 Vicenza, Italy
Interests: raw materials; structural integrity of welded joints and additively manufactured components; welding and heat treatment simulation; cast iron; stainless steels; materials selection
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Welding has been the most important joining technique applied to metallic materials since the early twentieth century when the arc welding technology developed. Since then, many innovations have been developed, from high energy density processes to solid state welding processes up to, most recently, hybrid metal diffusion and bonding. Advantages of welding processes are: Absence of holes that weaken the structure, reduction of production cost, faster speed of fabrication compared to bulky riveted/butted joints and so on. However, there are disadvantages, as well. Near the joint, the metallic material is altered, most of the time in a negative direction. Fatigue strength in particular is reduced compared to that of the parent metal because of metallurgical defects or stress concentration effects at the weld toe and/or root. Residual stresses are even induced that according to their sign could reduce the load bearing capacity and the fatigue strength of the joint. In this scenario, welding process numerical simulation results are extremely useful to optimize the process parameter affecting the microstructure and the mechanical properties of the welded joint. At the same time, static and fatigue strength assessment of welding joints via experiments are required to validate both numerical models and new design methodologies like the strain energy density or the peak stress approach.

This Special Issue aims to collect original works dealing with new advances in welded joints microstructure and mechanical characterization via numerical simulation and/or experiments. Papers that propose new numerical strategies as well as experimental fatigue data and design methodologies are particularly appreciated.

Prof. Dr. Paolo Ferro
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. Materials is an international peer-reviewed open access semimonthly 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 2600 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 numerical simulation
residual stress
fatigue
welding design
microstructure
modeling
mechanical properties
post welding heat treatment

Published Papers (11 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Editorial

Jump to: Research

2 pages, 180 KiB

Open AccessEditorial

Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments

by Paolo Ferro

Materials 2022, 15(10), 3694; https://doi.org/10.3390/ma15103694 - 21 May 2022

Viewed by 887

Abstract

Welding has been the most important joining technique applied to metallic materials since the early twentieth century when arc welding was introduced [...] Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

Research

Jump to: Editorial

20 pages, 8760 KiB

Open AccessArticle

Hole Morphology and Keyhole Evolution during Single Pulse Laser Drilling on Polyether-Ether-Ketone (PEEK)

by Yanmei Zhang, Gang Yu, Chongxin Tian, Zhiyong Li, Jiayun Shao, Shaoxia Li and Xiuli He

Materials 2022, 15(7), 2457; https://doi.org/10.3390/ma15072457 - 26 Mar 2022

Cited by 4 | Viewed by 1772

Abstract

Polyether-ether-ketone (PEEK), with its superior mechanical, chemical, and thermal properties, as well as high biocompatibility, has been used in aerospace, electronics, and biomedical applications. In this paper, a large number of experiments of single-pulse laser drilling on PEEK were performed to analyze the hole morphology and keyhole evolution, which were characterized by an optical microscope, charge-coupled device (CCD), and high-speed camera. A novel method is proposed to observe and measure the dimension of the processed hole rapidly right after laser drilling for special polymer materials with wear-resistance and non-conductivity. Morphological characteristics of holes are presented to illustrate the effect of pulse width and peak power on hole depth, hole diameter, and aspect-ratio. The obtained maximum drilling depth was 7.06 mm, and the maximum aspect-ratio was 23. In situ observations of the dynamic process of laser drilling, including the keyhole evolution together with ejection and vaporization behavior, were also carried out. The keyhole evolution process can be divided into three stages: rapid increment stage (0–2 ms) at a rate of 2.1 m/s, slow increment stage (2–4 ms) at a rate of 0.3 m/s, and stable stage (>4 ms). Moreover, the variation of dimensionless laser power density with the increase in pulse width was calculated. The calculated maximum drilling depth based on energy balance was compared with the experimental depth. It is proven that the laser–PEEK interaction is mainly influenced by a photothermal effect. Ejection is the dominant material-removal mechanism and contributes to over 60% of the depth increment during the rapid increment stage, while vaporization is dominant and contributes to about 80% of the depth increment during the slow increment stage. The results reveal the material removal mechanism for single-pulse laser drilling on PEEK, which is helpful to understand the dynamic process of keyhole evolution. This not only provides a processing window for future laser drilling of PEEK but also gives a guide for the manufacturing of other polymers. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

15 pages, 7873 KiB

Open AccessArticle

Eliminating the Brittleness Constituent to Enhance Toughness of the High-Strength Steel Weld Heat-Affected Zone Using Electropulsing

by Zhanglan Chen, Yunfeng Xiong, Xiaowen Li and Zongmin Li

Materials 2022, 15(6), 2135; https://doi.org/10.3390/ma15062135 - 14 Mar 2022

Cited by 2 | Viewed by 1506

Abstract

The evolution of the martensite–austenite (MA) constituent in the heat-affected zone (HAZ) of high-strength steel FH690 welds when subjected to electropulsing (EP) treatment was investigated herein, with the aim of eliminating brittle MA to enhance toughness. The features induced by EPT were correlated with the microstructure and fractography through scanning electron microscopy and electron backscatter diffraction analyses, together constituting an impact property evaluation. The Charpy V-notch impact results showed EPT could improve toughness of the HAZ from 34.1 J to 51.8 J (the calibrated value was 46 J). Examinations of EP-treated microstructure showed a preferred Joule heating: at the site of the MA constituent, the cleavage fractography introduced by the MA constituent was substituted with ductile dimples with various sizes. Decreases in grain size of 40% and 47% for the matrix and the retained austenite, respectively, were achieved; while for regions without the MA constituent, microstructural modification was negligible. The temperature rise at sample surface was less than 60 °C. The mechanism behind this favorable Joule heating for the MA constituent was correlated with the electrical properties of the MA constituent in contrast with martensite matrix. The toughness enhancement of the HAZ was thus attributed to the elimination of the coarse MA constituent. The present investigation suggested that electropulsing, characterized as a narrow-duration current, is a promising method for preferred elimination of brittle factors and thus improving the toughness of HAZ of high-strength steel within a limited region with a width less than 2 mm. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

22 pages, 9946 KiB

Open AccessArticle

FEM-Based Thermogram Correction for Inconel 625 Joint Hardness Clustering

by Wojciech Jamrozik, Jacek Górka, Bernard Wyględacz and Marta Kiel-Jamrozik

Materials 2022, 15(3), 1113; https://doi.org/10.3390/ma15031113 - 31 Jan 2022

Cited by 5 | Viewed by 1771

Abstract

Assessing the temperature of the joint in on-line mode is a vital task that is demanded to characterize the formations of terns formations that are taking place in a joint and result in reaching necessary properties of the joint. Arc welding generates a high amount of heat that is reflected by the metallic surface of the welded object. In the paper, a temperature measurement credibility increase method is described and evaluated. The proposed method is used to reduce the influence of the reflected temperature of the hot torch and the arc on the temperature distribution observed on the surface of the welded joint using an infrared camera. The elaborated approach is based on comparison between infrared observation of the solidifying weld and precisely performed finite element method (FEM) simulation. The FEM simulations were calibrated according to the geometry of the fusion zone. It allows to precisely model heat source properties. The best-reflected temperature correction map was selected and applied to obtain a temperature representation that differs from the FEM baseline by less than 10 °C. Precise temperature values allowed us to cluster welded joints in 3D feature space (temperature, hardness, linear energy). It was found that by using the k-means clustering method it is possible to distinguish between correct and faulty (in terms of too low mechanical properties) joints. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

19 pages, 5067 KiB

Open AccessArticle

Rapid Calculation of Residual Stresses in Dissimilar S355–AA6082 Butt Welds

by Francesco Leoni, Hallvard Gustav Fjær, Paolo Ferro and Filippo Berto

Materials 2021, 14(21), 6644; https://doi.org/10.3390/ma14216644 - 04 Nov 2021

Cited by 3 | Viewed by 1610

Abstract

An analytical model is proposed to rapidly capture the thermal and residual stresses values induced by the hybrid metal extrusion and bonding (HYB) process on dissimilar-metal butt-welded joints. The power input for two welding velocities is first assessed using a thermal–mechanical model solved by a heat generation routine written in MATLAB code. Subsequently, the obtained temperature history is used as input to solve the equilibrium and compatibility equations formulated to calculate the thermal and residual stresses. To verify the soundness of the analytical approach, a Finite Element numerical model of the entire process is carried out and results are compared with those coming from the proposed rapid method. It is found that the degree of accuracy reached by the analytical model is excellent, especially considering the tremendous time reduction when compared to that characterizing the standard numerical approach. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

16 pages, 10813 KiB

Open AccessArticle

Evolution of Microstructure in Friction Stir Processed Dissimilar CuZn37/AA5056 Stir Zone

by Anna Zykova, Andrey Chumaevskii, Anastasia Gusarova, Denis Gurianov, Tatiana Kalashnikova, Nickolai Savchenko, Evgeny Kolubaev and Sergei Tarasov

Materials 2021, 14(18), 5208; https://doi.org/10.3390/ma14185208 - 10 Sep 2021

Cited by 5 | Viewed by 1643

Abstract

Dissimilar friction stir processing on CuZn37/AA5056 was performed to study structural and phase evolution of a friction stir zone. Formation of 5–10 μm intermetallic compounds (IMCs) such as Al₂Cu was the main type of diffusion reaction between copper and aluminum. Other alloying elements such as Mg and Zn were forced out of the forming Al₂Cu grains and dissolved in the melt formed due to exothermic effect of the Al₂Cu formation. When solidified, these Zn-enriched zones were represented by α-Al+Al₂Cu+Zn phases or α-Al+Al₂Cu+Zn+MgZn regions. Eutectic Zn+MgZn was undoubtedly formed the melt after stirring had stopped. These zones were proven to be weak ones with respect to pull-off test since MgZn was detected on the fracture surface. Tensile strength of the stirred zone metal was achieved at the level of that of AA5056. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

46 pages, 34748 KiB

Open AccessArticle

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

by Łukasz Konat

Materials 2021, 14(16), 4541; https://doi.org/10.3390/ma14164541 - 12 Aug 2021

Cited by 7 | Viewed by 1846

Abstract

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. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

20 pages, 12650 KiB

Open AccessArticle

Residual Notch Stress Intensity Factors in Welded Joints Evaluated by 3D Numerical Simulations of Arc Welding Processes

by Alberto Campagnolo, Paolo Ferro, Luca Romanin and Giovanni Meneghetti

Materials 2021, 14(4), 812; https://doi.org/10.3390/ma14040812 - 08 Feb 2021

Cited by 14 | Viewed by 2039

Abstract

Approaches based on calculating Residual Notch Stress Intensity Factors (R-NSIFs) assume the weld toe to be a sharp V-notch that gives rise to a residual singular stress distribution close to the weld toe. Once R-NSIFs are determined, they might be included in local fatigue criteria for the structural strength assessment of welded joints based on NSIFs due to external cyclic loading. However, the numerical calculation of R-NSIFs through finite element (FE) simulations of the welding process requires extremely refined meshes to properly capture the residual stress singularity. In this context, the Peak Stress Method (PSM) has recently been adopted to estimate R-NSIFs due to residual stresses by means of coarse meshes of 2D 4-node plane or 3D 8-node brick elements. The aim of this work is to investigate the applicability of the PSM to estimate R-NSIFs in a butt-welded joint using coarse meshes of 3D 10-node tetra elements. The R-NSIF distribution at the weld toe line is estimated by applying the PSM to coarse meshes of 3D 10-node tetra elements, and the results are in agreement with those obtained using 3D 8-node brick elements. Accordingly, the PSM based on tetra elements further enhances the rapid estimation of R-NSIFs using coarse meshes and could be effective in analyzing complex 3D joint geometries. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

16 pages, 12794 KiB

Open AccessArticle

Material Model Development of Magnesium Alloy and Its Strength Evaluation

by Wenjia Huang, Ninshu Ma, Yunwu Ma, Toshiro Amaishi, Kenji Takada and Takayuki Hama

Materials 2021, 14(2), 454; https://doi.org/10.3390/ma14020454 - 19 Jan 2021

Cited by 3 | Viewed by 2352

Abstract

A new material model of magnesium alloys, combining both Hill’48 yield function and Cazacu’06 yield function, was developed and programmed into LS-DYNA using user subroutine, in which both slip dominant and twinning/untwinning dominant hardening phenomena were included. First, a cyclic load test was performed, and its finite element analysis was carried out to verify the new material model. Then, the deformation behaviors of the magnesium crash box subjected to the compressive impact loading were investigated using the developed material model. Compared with the experimental results, the new material model accurately predicted the deformation characteristics of magnesium alloy parts. Additionally, the effect of the thickness distribution, initial deflection and contact friction coefficient in simulation models on deformation behaviors were investigated using this validated material model. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

14 pages, 9367 KiB

Open AccessArticle

Investigation of the Residual Stress in a Multi-Pass T-Welded Joint Using Low Transformation Temperature Welding Wire

by Zhongyuan Feng, Ninshu Ma, Seiichiro Tsutsumi and Fenggui Lu

Materials 2021, 14(2), 325; https://doi.org/10.3390/ma14020325 - 10 Jan 2021

Cited by 8 | Viewed by 1901

Abstract

We investigated whether low transformation temperature (LTT) welding materials are beneficial to the generation of compressive residual stress around a weld zone, thus enhancing the fatigue performance of the welded joint. An experimental and numerical study were conducted in order to analyze the residual stress in multi-pass T-welded joints using LTT welding wire. It was found that, compared to the conventional welded joint, greater tensile residual stress was induced in the flange plate of the LTT welded joints. This was attributed to the reheat temperature of the LTT weld pass during the multi-pass welding. The formerly-formed LTT weld pass with a reheat temperature lower than the austenite finish temperature converted the compressive residual stress into tensile stress. The compressive residual stress was generated in the regions with a reheat temperature higher than the austenite finish temperature, indicating that LTT welding materials are more suitable for single-pass welding. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Figure 1

15 pages, 3510 KiB

Open AccessFeature PaperArticle

A Semi-Analytical Model for the Heat Generation during Hybrid Metal Extrusion and Bonding (HYB)

by Francesco Leoni, Øystein Grong, Paolo Ferro and Filippo Berto

Materials 2021, 14(1), 170; https://doi.org/10.3390/ma14010170 - 31 Dec 2020

Cited by 13 | Viewed by 1813

Abstract

Hybrid Metal Extrusion and Bonding (HYB) is a novel solid-state welding method for metals and alloys that utilises continuous extrusion as a technique to enable aluminium filler metal additions. In the present study, a new semi-analytical model for the heat generation during aluminium butt welding is presented. As a starting point, the classical Rosenthal thin plate solution for the pseudo-steady-state temperature distribution around a fully penetrating line source is invoked. Then, the associated heat generation is calculated by considering the individual contributions from the tip of the rotating pin, the pin shoulder, and the filler metal additions on the net power input. In a calibrated form, the model yields thermal efficiency factors that are in close agreement with those obtained from more sophisticated finite element analyses but with considerably less computational effort. Full article

(This article belongs to the Special Issue Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments)

► Show Figures

Journal Menu

Journal Browser

Assessment of Metallurgical and Mechanical Properties of Welded Joints via Numerical Simulation and Experiments

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (11 papers)

Editorial

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI