Effect of Welding Parameters on the Quality of Spot Welds Combining AHSS Steel and HSLA Steel

2013 ◽  
Vol 586 ◽  
pp. 162-165 ◽  
Author(s):  
Ľuboš Kaščák ◽  
Emil Spišák
Keyword(s):  
Fuel Consumption ◽  
Hsla Steel ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
Welding Current ◽  
High Strength ◽  
Vehicle Body ◽  
Welding Parameters ◽  
Low Alloy Steels ◽  
Ahss Steel

The resistance spot welding of dissimilar materials is generally more challenging than that of similar materials due to differences in the physical, chemical and mechanical properties of the base metals. Advanced high strength steels and high strength low alloy steels are utilized in automotive industry to reduce weight of the vehicle body and consequently lowering the fuel consumption to achieve the lowest possible fuel consumption, high active and passive safety of passengers while decreasing the amount of emission. The influence of the primary welding parameters, especially welding current, microhardness and tensile shear load bearing capacity of dissimilar welds between TRIP 40/70 as an Advanced High Strength Steel and H220PD as a High-Strength Low-Alloy steel has been investigated in this paper.

scholarly journals JOINING THE COMBINATION OF AHSS STEEL AND HSLA STEEL BY RESISTANCE SPOT WELDING

2013 ◽  
Vol 7 (2) ◽  
pp. 75-78 ◽  
Author(s):  
Ľuboš Kaščák ◽  
Emil Spišák ◽  
Ivan Gajdoš
Keyword(s):  
Fuel Consumption ◽  
Welded Joints ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
High Strength ◽  
Quality Analysis ◽  
Vehicle Body ◽  
Welding Parameters ◽  
Resistance Spot ◽  
Ahss Steel

Abstract The paper deals with the optimization of parameters of resistance spot welding and quality analysis of welded joints made by combination of galvanized Advanced High Strength Steel and High Strength Low Alloy steel. It is an advanced material combination utilized in automotive industry to reduce weight of the vehicle body and consequently lowering the fuel consumption to achieve the lowest possible fuel consumption, high active and passive safety of passengers while decreasing the amount of emission. The quality of welded joints was evaluated by destructive tests and non-destructive tests. The shear tensile test according to STN 05 1122 standard was used. Some samples were prepared for metallographic analysis, where the influence of the welding parameters on the structure of welded joint and occurrence of pores in the weld metal caused by evaporation of zinc from the coating was observed.

Springback Analysis in Bilayer Material Bending

2017 ◽  
Author(s):  
Chetan P. Nikhare
Keyword(s):  
Fuel Consumption ◽  
Elastic Recovery ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
Thick Layer ◽  
High Strength ◽  
Geometric Error ◽  
Forming Process ◽  
Tailor Welded Blanks ◽  
Geometric Defect

Exponential increase in the use of auto vehicles, and thus the fuel consumption, which relates to the air pollution, vehicle industry are in a strict environmental regulation from government. Due to which the innovation related to light-weighting is not only an option anymore but became a mandatory necessity to decrease the fuel consumption. To achieve this target, industry has been looking in fabricating components from high strength to ultra-high strength steels. With the usage of these material the lightweight was achieved by reducing a gage thickness. However due to their high strength property often challenges occurred are higher machine tonnage requirement, sudden fracture, geometric defect, etc. The geometric defect comes from elastic recovery of a material, which is also known as a springback. Springback is commonly known as a manufacturing defect due to the geometric error in the part, which would not be able to fit in the assembly without secondary operation or compensation in the forming process. Due to these many challenges, other research route involved is composite material, where light materials can be used with high strength material to reduce the overall vehicle weight. This generally includes, tailor welded blanks, multi-layer material, mechanical joining of dissimilar material, etc. Due to the substantial use of dissimilar materials, these parts are also called as hybrid components. It was noted that the part weight decreases with the use of hybrid components without compromising the integrity and safety. In this paper, a springback analysis was performed considering bilayer metal. For this two dissimilar materials aluminum and composite was considered as bonded material. This material was then bent in a channel forming set-up. The bilayer springback was compared in different condition like aluminum layer on punch side and then on die side. These results were then compared with the baseline springback of only aluminum thin and thick layer. It was found that the layer, which sees the punch side, matters due to the differences in elastic properties for both material and thus it directly influences the springback.

Effect of Metal-Composite Layer Thickness on Springback After U-Bending

2020 ◽  
Author(s):  
Chetan P. Nikhare
Keyword(s):  
Air Pollution ◽  
Fuel Consumption ◽  
Layer Thickness ◽  
Environmental Regulation ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
High Strength ◽  
Advanced High Strength Steels ◽  
Vehicle Weight ◽  
Geometric Defect

Abstract A sudden increase in the usage of automotive vehicles results in sudden increases in the fuel consumption which results in an increase in air pollution. To cope up with this challenge federal government is implying the stricter environmental regulation to decrease air pollution. To save from the environmental regulation penalty vehicle industry is researching innovation which would reduce vehicle weight and decrease the fuel consumption. Thus, the innovation related to light-weighting is not only an option anymore but became a mandatory necessity to decrease fuel consumption. To achieve this target, the industry has been looking at fabricating components from high strength to ultra-high strength steels or lightweight materials. With the usage of advanced high strength steels, the lightweight was achieved by reducing a gage thickness without compromising the strength aspect. However due to their high strength property often challenges occurred are higher machine tonnage requirement, sudden fracture, geometric defect, etc. The geometric defect comes from the elastic recovery of a material, which is also known as a springback. Springback is commonly known as a manufacturing defect due to the geometric error in the part, which would not be able to fit in the assembly without secondary operation or compensation in the forming process. It is learned that the springback of the material increases with an increase in the material strength and/or decrease in material thickness. In advanced high strength steels, higher strength and lower gage thickness options make the part prone to higher springback. Due to these many challenges, other research route involved is composite material, where light materials can be used with high strength material to reduce the overall vehicle weight. This generally includes, tailor welded blanks, multilayer material, mechanical joining of dissimilar material, etc. Due to substantial use of dissimilar materials, these parts are also called as hybrid components. It was noted that the part weight decreases with the use of hybrid components without compromising the integrity and safety. In the previously published paper in IMECE2017 the study was focused on equal layer thickness of metal and composite in bilayer material. In this paper, a springback analysis was performed considering bilayer metal by varying the thickness of the metal as well as the composite. For this two dissimilar materials aluminum and composite was considered as bonded material. This material was then bent on a free bend die. The bilayer springback was compared with different layer thickness of metal and composite and in different condition like aluminum layer on punch side and then on die side. These results were then compared with the baseline springback of only aluminum thin and thick layer.

scholarly journals Imperfections and Modelling of the Weld Bead Profile of Laser Butt Joints in HSLA Steel Thin Plate

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 151
Author(s):  
Patricio G. Riofrío ◽  
José A. M. Ferreira ◽  
Carlos A. Capela
Keyword(s):  
Laser Welding ◽  
Welded Joints ◽  
Hsla Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Weld Bead ◽  
Welding Parameters ◽  
Great Decrease ◽  
Weld Quality ◽  
Butt Joints

In many applications that use high strength steels, structural integrity depends greatly on weld quality. Imperfections and the weld bead geometry are influencing factors on mechanical properties of the welded joints but, especially in the fatigue strength, they cause a great decrease. The proper knowledge of these two factors is important from the nominal stress approach to the fracture mechanics approaches. Studies concerning the profile and imperfections of the weld bead in laser welding for thin plates of high strength steels are scarce. In this work, these two aspects are covered for five series single and double-welded joints, butt joints in a 3 mm thick HSLA steel, welded in a small range of welding parameters. The actual profiles captured with profilometer were modeled with proposed geometric parameters achieving an adequate fit with values of the coefficient of determination ℜ2 greater than 0.9000. Description of imperfections includes the distributions of porosity and undercuts. The evaluation of the weld quality, taking as guide the ISO 13919-1 standard determined B and D levels for the welded series while based on the stress-concentrating effect, showed a greater detriment in those series with undercuts and excessive penetration. The analysis of variance validated the results of the different combinations of laser welding parameters and showed, for the factorial experimental design, a more significant effect of the welding speed.

Investigation of Structural and Material Effects on Crashworthiness of Advanced High Strength Steel Columns

2003 ◽  
Author(s):  
Faycal Ben-Yahia ◽  
James A. Nemes ◽  
Farid Hassani
Keyword(s):  
Numerical Study ◽  
Hsla Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Column Height ◽  
Steel Columns ◽  
Advanced High Strength Steels ◽  
Element Simulation ◽  
Formed Channel ◽  
Good Agreement

An experimental and numerical study was performed to evaluate the crashworthiness of several advanced high strength steels. The behavior of two Dual Phase (DP) steels and an HSLA steel are compared by examining the crush response of longeron column specimens, experimentally and computationally. The closed section columns, fabricated by spot welding formed channel sections, in both single hat and double hat configurations were exposed to 182 kg and 454 kg axial impacts at different velocities. Final column height and impact force history were recorded and compared with results of finite element simulation of the columns. Good agreement was found between experiments and computations.

High Strength Low Alloy Steels in Naval Construction

1986 ◽  
Vol 2 (03) ◽  
pp. 145-162 ◽  
Author(s):  
T. W. Montemarano ◽  
B. P. Sack ◽  
J. P. Gudas ◽  
M. G. Vassilaros ◽  
H. H. Vanderveldt
Keyword(s):  
Hsla Steel ◽  
Development Program ◽  
Cost Savings ◽  
High Strength ◽  
Development Effort ◽  
Low Alloy Steels ◽  
Commercial Development ◽  
Ongoing Research ◽  
The Status ◽  
Alloy Steels

The Naval Sea Systems Command has recently certified a lower-cost alternative steel to the HY-80 steel presently used in construction of naval surface ships. This alternative steel is based on the commercial development of high strength low alloy (HSLA) steels originally directed to the offshore oil exploration platform and gas line transmission industries. The certification is a result of an ongoing research and development program begun in 1980. This paper addresses several aspects of the HSLA steel development effort, including a discussion of the properties and metallurgy of this steel, and the cost savings which are achievable. Finally, the status of the current and planned Navy HSLA usage and the R&D program is described.

Comparison between Modelled Influence of GMAW Parameters and Corresponding Mechanical Properties of Group 1 and 2 According to ISO/TR 15608 Steel T Joints

2021 ◽  
Vol 890 ◽  
pp. 17-24
Author(s):  
Aurel Valentin Bîrdeanu ◽  
Alin Constantin Murariu ◽  
Horia Florin Daşcău ◽  
Iuliana Duma
Keyword(s):  
Process Parameters ◽  
High Performance ◽  
Hsla Steel ◽  
Welding Process ◽  
High Strength ◽  
Industrial Applications ◽  
Steel Plates ◽  
Experimental Program ◽  
Welding Parameters ◽  
T Joints

Reproducibility in respect to welded structures realization is one of the main requirements for a wide variety of industrial applications. One of the international tendencies regarding the use of the steel is the replacing, in critical areas, of structural steels with high performance steel, e.g. with HSLA steels. The paper presents the results of a factorial designed experimental program focused on determining mathematical correlations between the GMAW process parameters for T joints of 4mm thick steel plates of structural (S235JR+AR according to SR EN 10025-2) and hot-rolled, high-strength low-alloy (HSLA) steel plates (S420MC according to EN 10025-4), respectively. A comparison between the obtained mathematical correlations that connect the welding parameters and the main mechanical characteristics is presented. The correlations can be used for applying the optimal combination of welding process parameters for realizing the T-joints of welded products.

Development of a Testing Method for the Identification of Friction Coefficients for Numerical Modeling of the Shear-Clinching Process

2015 ◽  
Vol 639 ◽  
pp. 469-476 ◽  
Author(s):  
Martin Müller ◽  
Ulrich Vierzigmann ◽  
Réjane Hörhold ◽  
Gerson Meschut ◽  
Marion Merklein
Keyword(s):  
Compression Test ◽  
Manufacturing Industry ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
High Strength ◽  
Ring Compression Test ◽  
Friction Coefficients ◽  
Testing Method ◽  
Ring Compression ◽  
Joining Process

Global competition as well as social and scientific megatrends strongly influence the modern car manufacturing industry. One of the most important approaches is the implementation of lightweight constructions. Therefore, the usage of high performance materials with tailored properties gains importance. For safety-relevant components such as automotive passenger cells it is necessary to minimize deformation to reduce the risk of injury for the vehicle occupants during a car accident. Thus, hot stamped high-strength steels have been established. High-strength and low formability of this kind of materials represent new challenges for joining technologies. One possibility to join high-strength steels is the newly developed shear-clinching technology. Due to the use of a combined cutting and joining process, the connection of dissimilar materials with high difference in strength and formability can be achieved. Further research to ensure process reliability and to improve the strength of the joint is required. One possible approach for this is the numerical investigation of the material flow during the joining process. Therefore, the definition of process parameters for the finite element model is necessary. A big impact on the quality of the results has the accuracy of the used friction values. As established testing methods are not suitable for modeling the rather complex tribological system between the joining partners of the shear-clinching process, an innovative testing method is needed. Studies in the field of sheet-bulk metal forming already demonstrated the applicability of the ring compression test for sheet metals. This paper presents a concept for the adaption of the ring compression test to the specific needs of the investigated shear-clinching process. The numerical identification of the friction coefficients is validated by experimental data and first results are qualified by experimental and simulative shear-clinching joints.

Development of an Empirical Model to Characterize Fracture Behavior During Forming of Advanced High Strength Steels Under Bending Dominated Conditions

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
S. Sriram ◽  
H. Yao ◽  
N. Ramisetti
Keyword(s):  
Research Work ◽  
High Strength Steels ◽  
High Strength ◽  
Optical Microscope ◽  
Low Carbon ◽  
Thickness Strain ◽  
Bending Tests ◽  
Advanced High Strength Steels ◽  
Applied Tension ◽  
Ahss Steel

Higher strength advanced high-strength steels (AHSS) such as DP780 and DP980 are more susceptible to fractures at bend radii during press stampings in comparison with more ductile low carbon sheet steels used by the automotive industry. Most research work to develop predictive guidelines for preventing failures at bend radii have centered on determining critical R/t ratios to avoid failures caused by bending. In this paper, results from bending tests with and without applied tension conducted on a number of AHSS steel lots to generate different conditions for fracture are presented. For bending tests with applied tension, measures of overall formability as a function of R/t ratio of the punch are presented. Consistent with other studies reported in literature, the overall formability was found to increase with increasing R/t ratio reaching saturation for higher R/t ratios. In addition, local formability was determined for all the bending tests by measuring the thickness strains at failure using an optical microscope. It was observed that the thickness strain at failure was dependent on the R/t ratio and the loading mode. Examination of fracture surfaces from the different tests using an SEM reveals that fracture initiation occurs primarily at the ferrite/martensite interphase boundary. To analyze the local loading conditions leading to fracture, 2D finite element analyses (FEA) of the different bending tests using ABAQUS standard were conducted. Results of the FEA were analyzed, and a parameter describing bending dominance in a stamping process was isolated. An empirical fracture criterion relating the thickness strain at fracture as a function of this parameter was developed. Implications of the generated results and their applications for part design and evaluation of stamping feasibility are also discussed.

Sign in / Sign up

Export Citation Format

Share Document