Effect of silica content on mechanical and microstructure behaviour of resistance spot welded advanced automotive TRIP steels

2021 ◽  
Author(s):  
Paranthaman V ◽  
Shanmuga Sundaram K ◽  
L Natrayan
Keyword(s):  
Fusion Zone ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Tensile Shear ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trip Steels ◽  
Resistance Spot ◽  
Spot Welded

Abstract This research investigates the effect of SiC wt% on mechanical and microstructure behavior of transformation induced plasticity (TRIP) 780 steels by resistance spot welding. The resistance spot welded samples were characterized for their properties such as hardness, tensile shear, scanning electron microscope, X-ray diffraction, ductility ratio and elongation. Results showed that the width of the nugget was closely associated with shear failure of the spot welds. X-ray diffraction analysis illustrated that the weld steels chemical composition improved in the heat-affected zones and retained austenite detected due to the influence of Si and C. Sample 4 microstructure exposed the equiaxed dimple and finer dendrites in the fusion zone. It also exhibited maximum force and fracture energy. Nano hardness was significantly decreased in the fusion zone of sample 4 due to the interface among micro alloying elements and the formation of nonmetallic presences that affected the TRIP steel hardness. Low ductility ratios were observed in steel 4 than the other weld steels due to higher tensile shear strength (TSS) and cross-tension strength (CTS) results. Fracture analysis exhibited ductile fracture with dimples and dendrites in the TRIP steels surface. The spot-welded samples mechanical properties are correlated to chemical elements, mainly Si existing in casted TRIP steels through the cooling phase of the resistance spot welding process.

Effect of Resistance Spot Welding Parameters on the Austenitic Stainless Steel 304 Grade by Using 23 Factorial Design

2011 ◽  
Vol 216 ◽  
pp. 666-670 ◽  
Author(s):  
Prachya Peasura
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Welding Time ◽  
Tensile Shear ◽  
Resistance Spot ◽  
Electrode Force

This research was study the effect of resistance spot welding process on physical properties. The specimen was austenitic stainless steel sheet of 1 mm. The experiments with 23 factorial design. The factors used in this study are welding current at 8,000 and 12,000 Amp, welding time at 8 and 12 cycle and electrode force were set at 1.5 and 2.5 kN. The welded specimens were tested by tensile shear testing according to JIS Z 3136: 1999 and macro structure testing according to JIS Z 3139: 1978. The result showed that the welding current, welding time and electrode force had interaction on tensile shear and nugget size at 95% confidential (P value < 0.05). Factors affecting the tensile shear are the most welding current of 12,000 amp., welding time of 8 cycle and electrode force of 2.5 kN. were tensile shear of 9.83 kN. The nugget size was maximum at 7.15 mm. on welding current of 12,000 amp., welding time of 12 cycle and electrode force of 1.5 kN This research can bring information to the foundation in choosing the appropriate parameters to resistance spot welding process.

scholarly journals Effect of Double Pulse Resistance Spot Welding Process on 15B22 Hot Stamped Boron Steel

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1279
Author(s):  
Hwa-Teng Lee ◽  
Yuan-Chih Chang
Keyword(s):  
Heat Input ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Double Pulse ◽  
Weld Nugget ◽  
Boron Steel ◽  
Welding Parameters ◽  
Tensile Shear ◽  
Resistance Spot

Double pulse resistance spot welding process by applying a second step welding current is a new pathway to alter the mechanical properties for advanced high strength steels. Herein, the resistance spot welding (RSW) of hot stamped boron steel 15B22 by one-step and two-step welding with different welding currents is investigated. The results of the tensile–shear test, size of the weld nugget, hardness distribution, microstructure, and failure mode of different welding parameters are analyzed. The weldment of the two-step RSW with a higher heat input exhibits a lower tensile–shear load and lower fracture energy when the size of the weld nugget is large. The microstructural study reveals the appearance of a partially melted zone and sub-critical heat affected zone in the weldment where the fracture readily occurred. Thus, the two-step RSW process weakens the strength of the sample, which is attributed to the partial softening in the weldment due to the higher heat input.

The Influence of Welding Parameters on Effected the Complete for Resistance Spot Welding on Mild Steel

2011 ◽  
Vol 214 ◽  
pp. 113-117 ◽  
Author(s):  
Prachya Peasura
Keyword(s):  
Mild Steel ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Welding Parameters ◽  
Welding Time ◽  
Tensile Shear ◽  
Resistance Spot ◽  
Electrode Force

This research was study the effect of resistance spot welding process on physical properties. The specimen was mild steel sheet metal. The experiments with full factorial design. The factors used in this study are welding current, welding time and electrode force. The welded specimens were tested by tensile shear testing according to JIS Z 3136: 1999 and macro structure testing according to JIS Z 3139: 1978. The result showed that both of welding current, welding time and electrode force had interaction on tensile shear and nugget size at 95% confidential (P value < 0.05). Factors affecting the tensile shear and nugget size are the most welding current 10,000 amp., welding time 10 cycle and electrode force 1 kN. were tensile shear 7.13 kN. and nugget size maximum 6.75 mm. This research can bring information to the foundation in choosing the appropriate parameters to resistance spot welding process.

THERMOMECHANICAL ANALYSIS OF THE RESISTANCE SPOT-WELDING PROCESS

2018 ◽  
Vol 10 (5) ◽  
pp. 449-455 ◽  
Author(s):  
Habib Lebbal ◽  
Lahouari Boukhris ◽  
Habib Berrekia ◽  
Abdelkader Ziadi
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Thermomechanical Analysis ◽  
Resistance Spot

Analysis of Electromagnetic Inverse Model of Resistance Spot Welding

2010 ◽  
Vol 160-162 ◽  
pp. 974-979
Author(s):  
Nai Feng Fan ◽  
Zhen Luo ◽  
Yang Li ◽  
Wen Bo Xuan
Keyword(s):  
Resistance Spot Welding ◽  
Regularization Method ◽  
Spot Welding ◽  
Influence Factors ◽  
Great Influence ◽  
Welding Process ◽  
Inverse Model ◽  
Resistance Spot ◽  
Inversion Theory

Resistance spot welding (RSW) is an important welding process in modern industrial production, and the quality of welding nugget determines the strength of products to a large extent. Limited by the level of RSW quality monitor, however, RSW has rarely been applied to the fields with high welding quality requirements. Associated with the inversion theory, in this paper, an electromagnetic inverse model of RSW was established, and the analysis of influence factors, such as the layout of the probes, the discrete program and the regularization method, was implemented as well. The result shows that the layout of the probe and the regularization method has great influence on the model. When the probe is located at the y direction of x-axis or the x direction of y-axis and Conjugate Gradient method is selected, a much better outcome can be achieved.

Micro Hardness in the Welded Area at Resistance Spot Welding

2016 ◽  
Vol 1138 ◽  
pp. 153-158
Author(s):  
Mihai Boca ◽  
Gheorghe Nagit ◽  
Laurenţiu Slătineanu
Keyword(s):  
Mechanical Properties ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Graphical Representation ◽  
Welding Process ◽  
Electrical Current ◽  
Micro Hardness ◽  
Current Time ◽  
Resistance Spot ◽  
Welding Spot

The resistance spot welding process represents the welding technology used to obtain assemblies trough welded spots characterized by adequate mechanical properties. This assembly process is used mainly into the automotive, petroleum and naval industries. It is applied due to the significant advantages concerning the technology and service properties of the obtained assembly. This paper purposes a study concerning the micro hardness change of an assembly made by resistance welding spot. The entire process of plastic deformations together with the solidification step developed in the presence of the heat generated during welding process determines the mechanical characteristics of the welded spot and, of course, of the assembly obtained. In such conditions, depending on the changes developed during the welding process, the micro hardness of the welded spot varies between the fusion area (FA) and heat affected zone (HAZ). In this way, the graphical representation of the micro hardness repartition gives clues about the weakness areas which don’t correspond to the requirements. As input factors, in this study, the values of current intensity, the electrical current time and the force pressure were considered. In order to solve the proposed problem and to graphically highlight the variation of the micro hardness obtained for welded points, it was used a classical welding device and a micro hardness device analyzer. The graphical representation shows that the micro-hardness and, as a consequence, some mechanical properties changes in the specified region and in the entire mass of the welded spot changes. In this way, the structure of welded spot is characterized by a variation of the hardness in the interest areas.

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