scholarly journals Determining Material Data for Welding Simulation of Presshardened Steel

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 740
Author(s):  
Jonny Kaars ◽  
Peter Mayr ◽  
Kurt Koppe
Keyword(s):  
Flow Stress ◽  
Room Temperature ◽  
Rapid Heating ◽  
Welding Process ◽  
High Strength ◽  
Cost Ratio ◽  
Material Data ◽  
Automotive Body ◽  
Nugget Growth ◽  
Martensitic State

In automotive body-in-white production, presshardened 22MnB5 steel is the most widely used ultra-high-strength steel grade. Welding is the most important faying technique for this steel type, as other faying technologies often cannot deliver the same strength-to-cost ratio. In order to conduct precise numerical simulations of the welding process, flow stress curves and thermophysical properties from room temperature up to the melting point are required. Sheet metal parts made out of 22MnB5 are welded in a presshardened, that is, martensitic state. On the contrary, only flow stress curves for soft annealed or austenitized 22MnB5 are available in the literature. Available physical material data does not cover the required temperature range or is not available at all. This work provides experimentally determined hot-flow stress curves for rapid heating of 22MnB5 from the martensitic state. The data is complemented by a comprehensive set of thermophysical data of 22MnB5 between room temperature and melting. Materials simulation methods as well as a critical literature review were employed to obtain sound thermophysical data. A comparison of the numerically computed nugget growth curve in spot welding with experimental welding results ensures the validity of the hot-flow stress curves and thermophysical data presented.

Pulsed LASER-(Micro)TIG Welding of Automotive Dissimilar Zn-Coated Advanced High Strength Steels Thin Sheets in Overlap Configuration

2016 ◽  
Vol 1138 ◽  
pp. 147-152
Author(s):  
Aurel Valentin Bîrdeanu
Keyword(s):  
High Performance ◽  
Pulsed Laser ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Industrial Applications ◽  
Cost Ratio ◽  
Hybrid Welding ◽  
Thin Sheets ◽  
Advanced High Strength Steels

The development and implementation into a high number of industrial applications of materials categorized as (Advanced) High Strength Steels (AHSS) due to their high performance per cost ratio is more and more present and this trend is also combined with the development and implementation of new joining technologies and processes, including laser-arc hybrid processes.The paper presents the results of applying Pulsed LASER-(micro)TIG hybrid welding process, for realizing overlap joints for Zn-coated (A)HSS materials in dissimilar configurations, joints that were presented as designed based on UltraLight Steel Auto Body (ULSAB) principles.The influence of main hybrid welding process parameters was investigated in order to establish if one can obtain joints with high values for the shear strength resistance for some of the actually used dissimilar steel combinations based on designs applied throughout ULSAB project and the autos built following these principles.

scholarly journals Assessment of Heat-Affected Zone Softening of Hot-Press-Formed Steel over 2.0 GPa Tensile Strength with Bead-On-Plate Laser Welding

2021 ◽  
Vol 11 (13) ◽  
pp. 5774
Author(s):  
Kwangsoo Kim ◽  
Namhyun Kang ◽  
Minjung Kang ◽  
Cheolhee Kim
Keyword(s):  
Laser Welding ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welding Process ◽  
High Strength ◽  
Hardness Test ◽  
Fracture Initiation ◽  
Hot Press ◽  
Automotive Body ◽  
Martensitic Microstructure

High-strength hot-press-formed (HPF) steels with a fully martensitic microstructure are being widely used in the fabrication of automotive body structure, and 2.0 GPa-strength HPF steel has recently been commercially launched. However, heat-affected zone (HAZ) softening is unavoidable in welding martensitic steel. In this study, the HAZ softening characteristic of 2.0 GPa HPF steel was investigated by applying a high-brightness laser welding process, wherein the heat input was controlled by varying the welding speed. Microstructural evaluation and hardness test results showed that the base metal with a fully martensitic microstructure was changed to the same type of fully martensitic microstructure in the weld metal, while relatively soft microstructures of tempered martensite and ferrite phase were partially formed in the intercritical HAZ (ICHAZ) and subcritical HAZ (SCHAZ) areas. In the tensile test, the joint strength was 10–20% lower than that of the base metal, and the fracture initiation was estimated at the ICHAZ/SCHAZ boundary, where the lowest hardness was confirmed by the nanoindentation technique.

Umformung von höchstfesten Aluminiumlegierungen*/Forming of high-strength aluminum alloys - Influence of the forming temperature on the formability of 7xxx-aluminum alloys

2017 ◽  
Vol 107 (10) ◽  
pp. 695-699
Author(s):  
B.-A. Prof. Behrens ◽  
S. Hübner ◽  
H. Vogt
Keyword(s):  
Aluminum Alloys ◽  
Room Temperature ◽  
High Strength ◽  
Eine Hohe ◽  
Specific Strength ◽  
Automotive Body ◽  
High Specific Strength ◽  
Body Construction ◽  
Forming Temperature ◽  
High Strength Aluminum Alloys

Der Fachartikel befasst sich mit der Umformbarkeit von höchstfesten Aluminiumlegierungen der 7xxx-Reihe. Diese haben eine hohe spezifische Festigkeit, weshalb sie ein großes Leichtbaupotenzial besitzen. Eine Umformung bei Raumtemperatur ist allerdings nur bedingt möglich und somit ein Einsatz im Automobilkarosseriebau derzeit kaum umsetzbar. Daher werden für diese Legierungen verschiedene Prozessrouten untersucht, welche durch Erwärmung der Platinen und Werkzeuge die Umformbarkeit verbessern.   This study deals with the formability of high-strength aluminum alloys of the 7xxx-series. These alloys have a high specific strength and, therefore, a high lightweight potential. A limited formability at room temperature of these alloys, however, limits the use in automotive body construction. To increase the formability there are different approaches. In this study, the influence of the blank as well as the forming tool temperature is investigated.

Analysis and Observations of Current Density Sensitivity and Thermally Activated Mechanical Behavior in Electrically-Assisted Deformation

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
James Magargee ◽  
Rong Fan ◽  
Jian Cao
Keyword(s):  
Flow Stress ◽  
Mechanical Behavior ◽  
Electric Current ◽  
Current Density ◽  
Rapid Heating ◽  
High Strength ◽  
Thermally Induced ◽  
Thermally Activated ◽  
Electrically Assisted ◽  
Wide Range

The flow of electric current through a metal during deformation has been observed to reduce its flow stress and increase its ductility. This observation has motivated the development of advanced “electrically-assisted” metal forming processes that utilize electric current to assist in the forming of high-strength and difficult-to-form materials, such as titanium and magnesium alloys. This method of heating provides attractive benefits such as rapid heating times, increased energy efficiency due to its localized nature, as well as the ability to heat the workpiece in the forming machine thus eliminating the transfer process between oven heating and forming. In this paper, a generalized method is proposed to relate applied electric current density to thermally activated mechanical behavior to better understand and improve the processing of metals during electrically-assisted deformation. A comparison is made of engineering metals studied experimentally as well as in the literature, and it is shown that the method provides insight into what some researchers have observed as the occurrence or absence of a “current density threshold” in certain materials. A new material parameter, “current density sensitivity,” is introduced in order to provide a metric for the relative influence of current density on a material's thermally activated plastic flow stress. As a result, the electric current necessary to induce thermal softening in a material can be estimated in order to effectively parameterize a wide range of advanced electrically-assisted forming processes. Thermally induced changes in material microstructure are observed and discussed with respect to the underlying deformation mechanisms present during electrically-assisted deformation. Finally, a strong correlation between thermally activated mechanical behavior and elastic springback elimination during sheet bending is demonstrated.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

ALUMINUM 713.0

Alloy Digest ◽  
1985 ◽  
Vol 34 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Room Temperature ◽  
High Strength ◽  
Heat Treating ◽  
Good Combination ◽  
Casting Alloy ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Permanent Mold Castings ◽  
Aluminum Base

Abstract ALUMINUM 713.0 is an aluminum-base casting alloy that ages at room temperature to provide high-strength sand and permanent-mold castings. It has a good combination of mechanical properties and its corrosion resistance is equivalent to that of the aluminum-silicon alloys. It is dimensionally stable. Among its many uses are housings, machinery parts, fittings, lever arms and brackets. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-263. Producer or source: Various aluminum companies.

Metodología para el desarrollo de trayectorias en la aplicación por el proceso de soldadura GMAW en un robot industrial

2019 ◽  
pp. 1-4
Author(s):  
Josué Rafael Sánchez-Lerma ◽  
Luis Armando Torres-Rico ◽  
Héctor Huerta-Gámez ◽  
Ismael Ruiz-López
Keyword(s):  
Mechanical Properties ◽  
Automotive Industry ◽  
Industrial Robot ◽  
Welding Process ◽  
High Strength ◽  
Test Material ◽  
Advantages And Disadvantages ◽  
Application Characteristics ◽  
Joining Process ◽  
Gmaw Welding

This paper proposes the development of the methodology to be carried out for the metal joining process through the GMAW welding process in the Fanuc LR Mate 200iD industrial robot. The parameters or properties were considered for the application to be as efficient as possible, such parameters as speed of application, characteristics of the filler material, gas to be used as welding protection. The GMAW welding process can be applied semiautomatically using a hand gun, in which the electrode is fed by a coil, or an automatic form that includes automated equipment or robots. The advantages and disadvantages of the GMAW welding process applied in a manual and automated way were commented. The mechanical properties of the materials to which said welding can be applied were investigated; The materials with which this type of welding can be worked are the high strength materials, which are used in the automotive industry, for the forming of sheet metal. To know the properties of the material, destructive tests were carried out on the test material to be used, as well as the mechanical properties of the welding.

Experimental investigation on resistance spot welding of dissimilar weld joints

2020 ◽  
pp. 095440892096835
Author(s):  
Rohit Verma ◽  
Kanwer Singh Arora ◽  
Lochan Sharma ◽  
Rahul Chhibber
Keyword(s):  
Welding Process ◽  
High Strength ◽  
Dynamic Resistance ◽  
Interstitial Free ◽  
Resistance Spot ◽  
Dissimilar Weld ◽  
Steel Sheets ◽  
Weld Joints ◽  
Resistance Spot Weld ◽  
Weld Current

In the present study, galvanized High Strength Interstitial Free (HIF) steel sheets, and Dual Phase (DP780) steel sheets were used for the investigations. Resistance spot weld joints were fabricated between dissimilar steel sheets. The variation in dynamic resistance (DR) with the change in welding process parameters such as weld current, weld time and electrode force were used for establishing the range of adequate weld nugget formation parameters. Effect of these parameters over tensile strength, nugget diameter and the observed failure mode was studied using one factor at a time (OFAT) approach. Microstructure and hardness of parent metal, fusion & HAZ region has also been studied.

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