scholarly journals Microstructure and Tensile-Shear Properties of Resistance Spot-Welded Medium Mn Steel

Metals ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 48 ◽  
Author(s):  
Qiang Jia ◽  
Lei Liu ◽  
Wei Guo ◽  
Yun Peng ◽  
Guisheng Zou ◽  
...  
Keyword(s):  
Tensile Shear ◽  
Shear Properties ◽  
Resistance Spot ◽  
Medium Mn Steel ◽  
Mn Steel ◽  
Spot Welded

scholarly journals Microstructure and Local Mechanical Properties of the Heat-Affected Zone of a Resistance Spot Welded Medium-Mn Steel

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3362
Author(s):  
Manfred Stadler ◽  
Ronald Schnitzer ◽  
Martin Gruber ◽  
Katharina Steineder ◽  
Christina Hofer
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Great Influence ◽  
High Strength ◽  
Total Elongation ◽  
Resistance Spot ◽  
Heat Treated ◽  
Medium Mn Steel ◽  
Mn Steel ◽  
Spot Welded

The properties of the heat-affected zone (HAZ) are reported to have a great influence on the mechanical performance of resistance spot welded advanced high strength steels. Therefore, in the present work, the HAZ of a medium-Mn steel is characterized regarding its microstructure and its mechanical properties depending on the distance to the fusion zone (FZ). In order to obtain the local mechanical properties of the HAZ, samples were heat-treated in a joule-heating thermal simulator using different peak temperatures to physically simulate the microstructure of the HAZ. By comparing the microstructure and the hardness of these heat-treated samples and the HAZ, the local peak temperatures within the HAZ could be determined. Subsequently, tensile tests were conducted, and the austenite phase fraction was measured magnetically on the physically simulated HAZ samples in order to determine the local mechanical properties of the HAZ. As verified by energy-dispersive X-ray spectroscopy, peak temperatures above 1200 °C led to a uniform distribution of manganese, resulting in a predominantly martensitic microstructure with high strength and low total elongation after quenching. Below 1100 °C, the diffusion of manganese is restricted, and considerable fractions of austenite remain stable. The austenite fraction increases almost linearly with decreasing peak temperature, which leads to an increase of the total elongation and to a slight decrease in the strength, depending on the distance to the FZ. Temperatures below 700 °C exhibit hardly any effect on the initial microstructure and mechanical properties.

Role of Intercritical Annealing in Enhancing the Cross-Tension Property of Resistance Spot-Welded Medium Mn Steel

2021 ◽  
Vol 30 (2) ◽  
pp. 1259-1269
Author(s):  
Bingge Zhao ◽  
Yuanfang Wang ◽  
Kai Ding ◽  
Guanzhi Wu ◽  
Tao Wei ◽  
...  
Keyword(s):  
Intercritical Annealing ◽  
Resistance Spot ◽  
Medium Mn Steel ◽  
The Cross ◽  
Mn Steel ◽  
Cross Tension ◽  
Spot Welded

Effects of welding parameters on tensile properties and fracture modes of resistance spot welded DP1200 steel

2021 ◽  
Vol 63 (2) ◽  
pp. 124-130
Author(s):  
Muhammed Elitas
Keyword(s):  
Welding Current ◽  
Welding Parameters ◽  
Tensile Shear ◽  
Shear Properties ◽  
Fracture Modes ◽  
Resistance Spot ◽  
Shear Loads ◽  
Heat Affected Zone Softening ◽  
Negative Effect ◽  
Spot Welded

Abstract In this study, the maximum tensile shear load bearing capacity and fracture modes of resistance spot welded DP1200 steel were investigated, and the tensile shear properties of the joints were evaluated. The effects of different welding parameters on tensile shear properties, fracture modes, microstructure, microhardness, and heat affected zone softening were examined. Weld processes were performed by using 2 to 6 bar electrode pressure as well as 5 and 7 kA weld currents. The microstructure of resistance spot welded materials was evaluated, and the hardness profiles were determined. Experimental results showed that welding current and electrode pressure had a significant effect on the load-displacement characteristics of DP1200 welds. Three different fracture modes were observed in the tensile shear loads. It was also observed that the expulsion had a negative effect on the tensile shear properties.

Enhanced Cross-Tension Property of the Resistance Spot Welded Medium-Mn Steel by In Situ Microstructure Tailoring

2021 ◽  
Vol 21 (2) ◽  
pp. 666-675
Author(s):  
Bingge Zhao ◽  
Yuanfang Wang ◽  
Kai Ding ◽  
Guanzhi Wu ◽  
Tao Wei ◽  
...  
Keyword(s):  
Resistance Spot ◽  
Medium Mn Steel ◽  
Mn Steel ◽  
Cross Tension ◽  
Spot Welded

scholarly journals Influence of the Cooling Time on the Microstructural Evolution and Mechanical Performance of a Double Pulse Resistance Spot Welded Medium-Mn Steel

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 270
Author(s):  
Manfred Stadler ◽  
Ronald Schnitzer ◽  
Martin Gruber ◽  
Katharina Steineder ◽  
Christina Hofer
Keyword(s):  
Fusion Zone ◽  
Heat Generation ◽  
Mechanical Performance ◽  
Electron Backscatter Diffraction ◽  
Cooling Time ◽  
Double Pulse ◽  
Resistance Spot ◽  
Medium Mn Steel ◽  
Mn Steel ◽  
Spot Welded

In the present work, the influence of the cooling time on the mechanical performance, hardness, and microstructural features of a double pulse resistance spot welded medium-Mn steel are investigated. Curves of the electrical resistance throughout the welding revealed that the cooling time strongly influences the heat generation during the second pulse. A second pulse after a short cooling time re-melts the center, and heat treats the edge of the primary fusion zone. This desired in-process heat treatment leads to a modification of the cast-like martensitic structure by recrystallization illustrated by electron backscatter diffraction measurements and to a homogenization of manganese segregations, visualized by energy-dispersive X-ray spectroscopy, which results in an enhanced mechanical performance during the cross tension strength test. In contrast, during excessively long cooling times, the resistance drops to a level where the heat generation due to the second pulse is too low to sufficiently re-heat the edge of the primary FZ. As a consequence, the signs of recrystallization disappear, and the manganese segregations are still present at the edge of the fusion zone, which leads to a deterioration of the mechanical properties.

Weldability Evaluation and Microstructure Analysis of Resistance-Spot-Welded High-Mn Steel in Automotive Application

2012 ◽  
Vol 83 (4) ◽  
pp. 352-357 ◽  
Author(s):  
Dulal Chandra Saha ◽  
Sangho Han ◽  
Kwang Geun Chin ◽  
Ildong Choi ◽  
Yeong-Do Park
Keyword(s):  
Microstructure Analysis ◽  
Automotive Application ◽  
Resistance Spot ◽  
Mn Steel ◽  
Spot Welded

Effect of Initial Gap on Tensile Strength of Resistance Spot Welded Joints

2010 ◽  
Vol 154-155 ◽  
pp. 325-328
Author(s):  
Hai Jun Yang ◽  
Yan Song Zhang ◽  
Jie Shen ◽  
Xin Min Lai
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Welded Joints ◽  
Fe Model ◽  
Tensile Shear Strength ◽  
Tensile Shear ◽  
Resistance Spot ◽  
Nugget Formation ◽  
Spot Welded

It has been proved that the initial gap has obvious influence on nugget formation, but little works focused on the effect of initial gap on the tensile strength of resistance spot welded (RSW) joints. In this paper, a 3D FE model was built for solving this question. The results show that, even though there are some fluctuations of weld diameter and tensile strength of RSW joints with initial gap, the tensile strength and weld diameter of welded joints with initial gap are still larger than that of welded joints without gap, which confirm that the influence of initial gap on tensile shear strength is little significant. The computation results agree well with experiment.

Effects of Inoculation on Microstructures and Mechanical Properties of Resistance Spot Welded Magnesium Alloy Joints

2012 ◽  
Vol 482-484 ◽  
pp. 2142-2147
Author(s):  
Hai Xuan Sun ◽  
Da Qian Sun ◽  
Xin Zui Wang ◽  
Huan Cai Yin ◽  
Wen Bo Cheng
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
High Stress ◽  
Tensile Shear ◽  
Average Width ◽  
Dendritic Crystal ◽  
Resistance Spot ◽  
Stress Zone ◽  
High Stress Zone ◽  
Spot Welded

Resistance spot welded magnesium alloy joints contain the nugget and heat affected zone (HAZ), and the weld nugget of magnesium alloy generally contains two different microstructures, the cellular dendritic crystals at the edge of the nugget and the equiaxed dendritic crystals in the center of the nugget. Characteristics of cellular dendritic crystals make the cellular dendritic crystals zone to be the weak area, and the more unfortunate thing is that it is located in the high-stress zone, which further degrades the mechanical properties of the joints. Based on this conditions, inoculation would be tried to refine the cellular dendritic crystals in order to improve the mechanical properties of resistance spot welded magnesium alloy joints. Al-10Sr was chosen as the inoculant in this experiment. As the addition of Al-10Sr increases from zero to 1.4mg, the average width of cellular dendritic crystal zone decreases from 332μm to 58μm while the microstructure tends to be refined, accordingly, tensile shear load of the joints increases by 24.3% from 2.379 KN to 2.959 KN. It is favorable to select a relative higher content of Al-10Sr addition to improve the mechanical properties of the spot welded magnesium alloy joints.

Sign in / Sign up

Export Citation Format

Share Document