scholarly journals Stored Energy Welding Technology of Ultra-Thin Sheet Stainless Steel

2013 ◽  
Vol 749 ◽  
pp. 27-30
Author(s):  
Hao Bin Zhou ◽  
Ju Lian Ma ◽  
Xiang Qian Xu

Considering the characteristics of the multilayered ultra-thin sheet stainless steel, by chosen the proper equipments and stored energy welding technology, the optimizing welding parameters are got from the condenser discharge spot welding experiments. The energy stored in the capacitor group is controlled by the energy required during welding and the discharge current is controlled by the size of dynamic resistance in resistance spot welding. So those control ways can better solve the hard problem of choosing welding parameter. The joint strength of ultra-thin sheet stainless steel is ensured by the reasonable quality assessment methods. The processed spot-welded joints are of good quality and appearance.

2006 ◽  
Vol 505-507 ◽  
pp. 205-210
Author(s):  
Wen T. Chien ◽  
S.W. Chang

A predictive model is presented for the prediction of shear strength in laser welding AISI304 stainless steel. Welding experiments conducted using a pulsed Nd:YAG laser machine while the laser welding parameters and their levels have been arranged according to design of experiments of Taguchi method. The tensile tests are performed after welding and the measurements of tensile strength are further calculated for shear strength. The data can be analyzed using the principles of Taguchi method for determining the optimal laser welding parameters and for investigating the most significant laser welding parameter on shear strength. Furthermore, the results are treated as the training and recalling patterns for constructing a predictive model using back-propagation neuron network to predict shear strength for the range of laser welding operation tested. It is indicated that welding speed is the most significant affecting parameters on shear strength. In addition, an increase in welding speed causes a decrease in shear strength is found. An average error 5.75%for shear strength can be found by comparing the experimental results obtained from conducting verification tests with the predicting values obtained from the established predictive model. It shows that the predictive model is capable of good predicting behavior of laser welding AISI304 stainless steel.


2012 ◽  
Vol 706-709 ◽  
pp. 2925-2930 ◽  
Author(s):  
Abderrazak El Ouafi ◽  
R. Belanger ◽  
Michel Guillot

On-line quality assessment becomes one of the most critical requirements for improving the efficiency of automatic resistance spot welding (RSW) processes. Accurate and efficient model to perform non-destructive quality estimation is an essential part of the assessment. Besides the usual welding parameters, various measured variables have been considered for quality estimation in RSW. Among these variables, dynamic resistance (DR) gives a relative clear picture of the welding nugget formation and presents a significant correlation with the RSW quality indicators (QI). This paper presents a structured approach developed to design an effective DR-based model for on-line quality assessment in RSW. The proposed approach examines welding parameters and conditions known to have an influence on weld quality, and builds a quality assessment model step by step. The modeling procedure begins by examining, through a structured experimental design, the relationships between welding parameters, typical characteristics of the RD curves and multiple welding QI. Using these results and various statistical tools, different integrated quality assessment models combining an assortment of DR attributes are developed and evaluated. The results demonstrate that the proposed approach can lead to a general model able to accurately and reliably provide an appropriate assessment of the weld quality under variable welding conditions.


Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 951 ◽  
Author(s):  
Ning Guo ◽  
Xin Zhang ◽  
Changsheng Xu ◽  
Hao Chen ◽  
Yunlong Fu ◽  
...  

The underwater wet welding (UWW) technology is rapidly developing as a crucial method in the maintenance work of marine equipment and offshore platform. The rapid development of UWW technology has also exposed the problems to be solved urgently. Therefore, the influence of welding parameters on the weld appearance and welding spatters was investigated in this paper. The main welding parameters used in the study are welding current, arc voltage, welding speed and the contact tip-to-work distance (CTWD). Through the orthogonal test, it is found that, as each welding parameter increases within a certain range, the amounts of welding spatter decreases first and then increases, and the weld forming effect first becomes better and then deteriorates. The amount of wet welding spatter is mainly affected by the welding speed. When the welding speed is low, the splash is more, and the change of the welding current and the arc voltage has a little effect on the number of spatters. When the welding speed is large, the spatter is most with a small welding current and a large arc voltage. After evaluating the weld morphology obtained by welding under various parameters, a set of optimal parameters was obtained. The best parameters for the underwater wet welding of stainless steel with self-shielded flux-cored wire are determined to be 200 A-29 V-2.0 mm/s-15 mm (CTWD).


2020 ◽  
pp. 009524432096152
Author(s):  
Asil Ayaz ◽  
Aydin Ülker

In this study, a new method was proposed to reduce the keyhole volume with friction stir spot welding process and improve the lap joint shear load-carrying capacity of the weld by analyzing the effects of tool rotation speed, plunge depth and dwell time on the weld. Single lap shear tests were carried out to determine the influences of the welding parameters on the mechanical behavior of the welds. The quality of the joint was evaluated by examining the characteristics of the joint as a result of the lap joint shear load. For friction stir spot welding of the acrylonitrile butadiene styrene samples, the experiments were designed according to Taguchi’s L9 orthogonal array in a randomized way. From the analysis of variance and the signal-to-noise ratio, the significant parameters and the optimum combination level of the parameters were obtained. It was found that using a tool rotation of 1000 rpm, plunge depth 11.5 mm and dwell time of 40 s, an improved joint strength can be obtained. The results showed that joint strength was improved by an amount of 20% as compared with the optimum welding parameters to the initial welding parameters. Macrostructure examination plays an important role to determine the joint strength and evaluate the influences of each welding parameters. So, weld morphology was investigated by morphological analysis and visual comparisons. It was also observed failure modes for fractured samples having the highest, moderate and lowest lap joint shear load.


2011 ◽  
Vol 391-392 ◽  
pp. 661-665
Author(s):  
Yan Yu ◽  
Feng Xue Wang ◽  
Zai Dao Yang

A series of spot welding technology, joint mechanical properties and microhardness test analysis of TRIP800 high strength steel were researched. Based on these experiments and analysis, effect of spot welding parameters such as welding current, welding time and electrode pressure on joint mechanical properties were explored. The relevant spot welding parameters of TRIP800 high strength steel of spot welding were recommended, such as welding current is7.5~8.0KA, electrode pressure is 450 kgf and welding time is 20cyc. Welding electrode should be to ensure that as much as possible and clean the surface,to avoid welding current and welding time is too high or too long, as well as forging lack of power, to prevent the occurrence of welding defects.


2014 ◽  
Vol 660 ◽  
pp. 120-124 ◽  
Author(s):  
Farizah Adliza Ghazali ◽  
Yupiter HP Manurung ◽  
Mohamed Ackiel Mohamed

This paper presents the effects of spot welding parameters on multi-response weld quality and optimizes the governing parameters of Resistance Spot Welding (RSW) towards the tensile shear strength and nugget size using Taguchi method. The main affecting welding parameters such as electrode force, weld time and weld current were determined as the basis for quality evaluation. The selected quality features were classified into shear strength and nugget size which were required for application with highly dynamic loading. The optimum welding parameter was obtained using multi signal-to-noise ratio (MSNR) and the significant level of welding parameters was further analysed using analysis of variance (ANOVA). Based on the results, electrode force was found to be most effective parameter affecting shear strength and nugget size. The experiment was conducted at optimum welding parameter and validated the used of multi-objective Taguchi method for enhancing performance and optimizing the welding parameters in RSW process.


Author(s):  
Naveen Pandey ◽  
Dinesh Dubey

Tungsten inert gas welding is popular known welding technique for ferrous & nonferrous. Stainless steel grade 3HQ (S30430) is a specialized wire grade with very wide usage for manufacturer of stainless steel fastener. It has now totally replaced Grade 384 and 305 for heading application. The stable austenitic structure makes 302HQ nonmagnetic, even after substantial cold work, and also results in excellent toughness, even down to cryogenic temperatures. This paper attempts in optimizing the Tungsten Inert Gas (TIG) welding process parameter. The effect of various parameters and their influence is important to determine the strength of welded joint. To obtain a good quality weld, it is therefore, essential to control the input welding parameters. Therefore appropriate selection of input welding parameter is necessary in order to obtain a good quality weld and subsequently increase the productivity of manufacturing industry. This paper present multi objective optimization using grey relation analysis (GRA) for S30430 with TIG process to determine the suitable selection of parameters Experiment were conducted according to Taguchi's design of experiments (DOE) with orthogonal array L9 is used, mathematical model was developed using parameters such as speed (mm/min), current (Amp), voltage (V), depth of penetration (mm). After conducting experiment and collecting data, signal to noise ratio were determined by using Minitab18 and it is used to obtain optimum level for every input parameter.


2020 ◽  
Vol 2 (106) ◽  
pp. 68-77
Author(s):  
A.A. Shehab ◽  
S.A. Nawi ◽  
A. AAG Al-Rubaiy ◽  
Z. Hammoudi ◽  
S.A. Hafedh ◽  
...  

Purpose: The present work aims to investigate the influence of CO2 laser spot welding (LSW) parameters on welding profile and mechanical properties of lap joint of AISI 321 thin sheet metals, and analyze the welding profile numerically by finite element (FE) method. Design/methodology/approach: The weld carried out using 150 W CO2 continues wave laser system. The impact of exposure time and laser power on the welding profile was investigated using an optical microscope. Microhardness and tensile strength tests were used to evaluate the mechanical properties of the joint. Ansys software was utilized to simulate the welding profile numerically. Findings: The results revealed that 2 s exposure time and 50 W power have led to uniform welding profile and highest shear force (340 N), lower hardness gradient across the heat affected zone (HAZ) and fusion zone (FZ). Finite element (FE) analysis of the welding profile showed good agreement with experimental analysis. Research limitations/implications: The selection of laser spot welding parameters for thin sheet metal was critical due to the probability of metal vaporisation with extra heat input during welding. Practical implications: Laser welding of AISI 321 steel is used in multiple industrial sectors such as power plants, petroleum refinement stations, pharmaceutical industry, and households. Thus, selecting the best welding parameters ensures high-quality joint. Originality/value: The use of CO2 laser in continuous wave (CW) mode instead of pulse mode for spot welding of thin sheet metal of AISI 321 austenitic stainless steel consider a real challenge because of the difficulty of control the heat input via proper selection of the welding parameters in order to not burn the processed target. Besides, the maintenance is easier and operation cost is lower in continuous CO2 than pulse mode.


2013 ◽  
Vol 7 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Hitomi Nishibata ◽  
◽  
Shota Kikuchi ◽  
Manabu Fukumoto ◽  
Masato Uchihara

This paper describes a Single-Side resistance Spot Welding (SSSW) process which is expected to be a productive welding technology for the joining of stamped sheet panels to hollow parts for auto bodies. To obtain guidelines for making a sound weld with the SSSW process, the effects of welding parameters and the alignment of specimens on nugget growth are investigated experimentally. In addition, a numerical study is carried out to discuss the mechanism of nugget growth in the SSSW process.


Author(s):  
S.P. Sundar Singh Sivam ◽  
A. Thirugnanam ◽  
K. Saravanan ◽  
D. Kumaran ◽  
M. Suresh

Electrode deterioration by deformation and chemical reaction during resistance spot welding of steel sheets confirming to AISI1020 is an issue for class II electrode. In view of this, the present study carried out the impacts of squeeze, weld, current and pressure on the nugget diameter, height, force and waviness of welding joint in electrical resistance spot welding of 0.8mm and 1.5 mm thickness of steel sheets with class II electrode to achieve the benefits of cost saving and quality products. A timer and current controlled electrical resistance spot welding machine having 120 kVA capacities were used. During welding process, current periods of 5, 10, 15, 20 and 25 were selected and it was adjusted by increasing from 8 to 10 kA. The optimum welding parameter for multi objectives was obtained using multi signal to noise ratio and the significant level of the welding parameters was further analysed by analysis of variance for all responses. Based on the confirmation test results, it is found out that the developed model can be effectively used to predict the size of weld zone which can improve the welding quality and performance in GRA. The details of welded joint generated by class II electrode were measured and results were analysed in detail.


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