Constitutive relationship of fusion zone in the spot welds of advance high strength steels

2019 ◽  
Vol 45 ◽  
pp. 624-633 ◽  
Author(s):  
Cheng Luo ◽  
Yansong Zhang
Keyword(s):  
Fusion Zone ◽  
High Strength Steels ◽  
High Strength ◽  
Constitutive Relationship ◽  
Spot Welds ◽  
Relationship Of

Ultimate Load Capacity of Spot Welds Made of Ultra High Strength Steels

2011 ◽  
Author(s):  
Zongfen Zhang ◽  
Chris Chen ◽  
Gregory Zywicki ◽  
Brad Blaski ◽  
James Blenman
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
High Strength Steels ◽  
High Strength ◽  
Spot Welds ◽  
Ultimate Load Capacity ◽  
Ultra High Strength Steels

scholarly journals Investigation of the Failure of Advanced High Strength Steels Heterogeneous Spot Welds

Metals ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 111 ◽  
Author(s):  
Thibaut Huin ◽  
Sylvain Dancette ◽  
Damien Fabrègue ◽  
Thomas Dupuy
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Spot Welds ◽  
Advanced High Strength Steels

scholarly journals HAZ Microstructures and Local Mechanical Properties of High Strength Steels Resistance Spot Welds

2011 ◽  
Vol 51 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Sylvain Dancette ◽  
Veronique Massardier-Jourdan ◽  
Damien Fabrègue ◽  
Jacques Merlin ◽  
Thomas Dupuy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Spot Welds ◽  
Resistance Spot ◽  
Resistance Spot Welds

scholarly journals Spot Weld Strength Determination Using the Wedge Test: In Situ Observations and Coupled Simulations

2010 ◽  
Vol 24-25 ◽  
pp. 299-304 ◽  
Author(s):  
Rémi Lacroix ◽  
Joël Monatte ◽  
Arnaud Lens ◽  
Guillaume Kermouche ◽  
J.M. Bergheau ◽  
...  
Keyword(s):  
Energy Analysis ◽  
High Strength Steels ◽  
High Strength ◽  
Spot Weld ◽  
Weld Strength ◽  
Spot Welds ◽  
Local Loading ◽  
Advanced High Strength Steels ◽  
Strength Determination

This paper describes an innovative way to characterize the strength of spot welds. A wedge test has been developed to generate interfacial failures in weldments and observe in-situ the crack propagation. An energy analysis quantifies the spot weld crack resistance. Finite Element calculations investigate the stresses and strains along the crack front. A comparison of the local loading state with experimentally observed crack fronts provides the necessary data for a failure criterion in spot weld fusion zones. The method is applied to spot welds of Advanced High Strength steels.

Microstructural Evolution and Tensile Strength of Laser-Welded Butt Joints of Ultra-High Strength Steels: Low and High Alloy Steels

2021 ◽  
Vol 883 ◽  
pp. 250-257
Author(s):  
Mikko Hietala ◽  
Atef Hamada ◽  
Markku Keskitalo ◽  
Matias Jaskari ◽  
Jani Kumpula ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fusion Zone ◽  
Microstructural Evolution ◽  
Laser Energy ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Tests ◽  
Butt Joints ◽  
Dissimilar Joints ◽  
Ultra High Strength Steels

The present study is focused on joining two ultra-high strength steels plates of 3 mm thickness using laser-welding. Abrasion resistant steel with martensitic structure, tensile strength (Rm) ≥ 2 GPa, and cold-deformed austenitic stainless steel, Rm 1.3 GPa, were used for the dissimilar butt joints. Two different laser energy inputs, 160 and 320 J/mm, were presented during welding. The weld morphology and microstructural evolution of the fusion zone were recorded using optical microscopy and electron back scattering diffraction (EBSD), respectively. The mechanical properties of the dissimilar joints were evaluated by hardness measurements and tensile tests. It was found that fusion zone has undergone a change in morphology and microstructure during welding depending upon the energy input. Analysis of the microstructural evolution in the fusion zone by EBSD examination showed that the presence of a mixture of small austenite grains in a matrix of martensite. The changes in hardness profiles and tensile strength under the experimental parameters were further reported.

Investigations on the Mechanical Behavior of Advanced High Strength Steels Resistance Spot Welds in Cross Tension and Tensile Shear

2010 ◽  
Vol 89-91 ◽  
pp. 130-135 ◽  
Author(s):  
Sylvain Dancette ◽  
Véronique Massardier-Jourdan ◽  
Jacques Merlin ◽  
Damien Fabrègue ◽  
Thomas Dupuy
Keyword(s):  
Three Dimensional ◽  
High Strength Steels ◽  
Complex Loading ◽  
High Strength ◽  
Weld Strength ◽  
Tensile Shear ◽  
Spot Welds ◽  
Advanced High Strength Steels ◽  
Cross Tension ◽  
Failure Types

Advanced High Strength Steels (AHSS) are key materials in the conception of car body structures, permitting to reduce their weight while increasing their behavior in crash conditions. Nevertheless, the weldability of AHSS presents some particular aspects, in that complex failure types involving partial or full interfacial failure can be encountered more often than with conventional mild steels during destructive testing, despite high spot weld strength levels. This paper aims at characterizing the behavior of different AHSS spot welds under two quasi-static loading conditions, tensile shear and cross tension, often used in the automotive industry for the determination of their weldability. Interrupted cross tension and tensile shear tests were performed and spot welds failure was investigated with optical micrographs, SEM fractography and 3D-tomography in order to follow the three-dimensional crack paths due to the complex loading modes. A limited number of failure zones and damage mechanisms could be distinguished for all steel grades investigated. Moreover, numerical simulation of the tests was used to better understand the stress state in the weld and the influence of geometrical features such as weld size on the occurrence of the different failure types.

Ab Initio Study of Weldability of a High-Manganese Austenitic Twinning-Induced Plasticity (TWIP) Steel Microalloyed with Boron

2016 ◽  
Vol 1812 ◽  
pp. 35-40 ◽  
Author(s):  
Humberto Hernández-Belmontes ◽  
Ignacio Mejía ◽  
Cuauhtémoc Maldonado
Keyword(s):  
Fusion Zone ◽  
Twip Steel ◽  
Mechanical Performance ◽  
Research Work ◽  
Base Material ◽  
High Strength Steels ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Microstructural Changes ◽  
Twip Steels

ABSTRACTHigh-Mn Twinning-Induced Plasticity (TWIP) steels are advanced high-strength steels (AHSS) currently under development; they are fully austenitic and characterized by twinning as the predominant strengthening mechanism. TWIP steels have high strength and formability with an elongation up to 80%, which allows reduction in automotive components weight and fuel consumption. Since the targeted application field of TWIP steels is the automotive industry, steels need high mechanical performance with good weldability and excellent corrosion resistance. However, there is lack of information about the weldability behavior of these advanced steels. This research work aims to study the weldability of a new generation of high-Mn austenitic TWIP steels microalloyed with B. Weldability was examined using spot welds produced by Gas Tungsten Arc Welding. Microstructural changes were examined using light optical metallography. Segregation of elements in the weld joint was evaluated using point and elemental mapping chemical analysis by Scanning Electron Microscopy and Electron-Dispersive Spectroscopy; while the hardness properties were examined with Vickers microhardness testing (HV25). Experimental results show that the welded joint microstructure consists of austenitic dendritic grains in the fusion zone, and equiaxed grains in the heat affected zone. Notably, the boron microalloyed TWIP steel exhibited poor weldability, showing hot cracking. Additionally, the studied TWIP steels showed a high degree of segregation in the fusion zone; Mn and Si segregated into the interdendritic regions, while Al and C preferentially segregated in dendritic areas. Finally, the welded joints of the TWIP steels showed microhardness values lower than the base material. In general, the present TWIP steels have problems of weldability, which are corroborated with microstructural changes, elements segregation and microhardness loss.

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