Volume 4 Issue 11 November-2016 Pages-6053-6058 ISSN(e):2321-7545 Website: http://ijsae.in DOI: http://dx.doi.org/10.18535/ijsre/v4i11.08 Optimization of Parameter (Mig ) Using Taguchi Method Authors Pappu Kumar 1, Prof. Prakash Kumar 2 1 Post Graduate Scholar, Deptt. of Production Engg., B.I.T, Sindri, Dhanbad, Jharkhand-828123, India. 2 Assistant Professor, Deptt. Of Production Engg., B.I.T, Sindri, Dhanbad, Jharkhand-828123, India. Email- 1 pappubitsindri104@gmail.com, 2 rawatprakash3671@gmail.com ABSTRACT Metal Inert Gas welding (MIG) process is an important component in many industrial operations. The GMA weldingparameters are the most important factors affecting the quality, productivity and cost of welding. This paper presents theinfluence of welding parameters like welding current (Amp.), welding voltage (Volt.), &Wire Feed Rate (m/min) on Tensile strength. A plan of experiments based on Taguchi Method has been used to acquire the data. AnOrthogonal array, signal to noise (S/N) ratio and analysis of variance (ANOVA) are employed to investigate the weldingcharacteristics of mild steel& optimize the welding parameters. Finally the conformations tests have been carried outto compare the predicated values with the experimental values confirm its effectiveness in the analysis of Tensile Strength. Keywords:MIG, Tensile Strength, Taguchi Method, Analysis of Variance (ANOVA) 1. INTRODUCTION Metal Inert Gas welding is one of the most widely used processes in industry. The input parameters play a very significant role in determining the quality of a welded joint. In fact, weld geometry directly affects the complexity of weld schedules and thereby the construction and manufacturing costs of steel structures and mechanical devices. Therefore, these parameters affecting the arc and welding should be estimated and their changing conditions during process must be known before in order to obtain optimum results; in fact a perfect arc can be achieved when all the parameters are in conformity. These are combined in two groups as first order adjustable and second order adjustable parameters defined before welding process [1]. Former are welding current (Amp.), welding voltage (Volt.), & Wire Feed Rate (m/min). These parameters will affect the weld characteristics to a great extent. Because these factors can be varied over a large range, they are considered the primary adjustments in any welding operation. Their values should be recorded for every different type of weld to permit reproducibility. 2. EXPERIMENTAL PROCEDURE Accordingly the present study has been done through the following plan of experiment. a) The workpiece required for the experiment is prepared in workshop using lathe mahine. b) The prepared workpieces was cut into two pieces and V- groovewas made on the edge of the workpieces. c) Performed welding operation on specimens in various welding environments involving various combinations of process control parameters like: welding current, welding voltage and wire feed rate. 2.1. Process Variablesand Their Limits The working ranges of the parameters for subsequent design of experiment, based on Taguchi s L9 Orthogonal Array (OA) design have been selected. In the present experimental study, welding current, Pappu Kumar, Prof. Prakash Kumar IJSRE Volume 4 Issue 11 November 2016 Page 6053
welding voltage and wire feed rate have been considered as process variables. The process variables with their units (and notations) are listed in Table 3. Table No. 2.1. Process variables and their values SL NO Table No.-2.2. Taguchi s L 9 orthogonal array (Amp.) (A) Voltage (volt.) (B) 1 50 15 3 2 100 19 4 3 150 23 5 Wire Feed Rate (m/min.) (C) (Amp.) Voltage (volt.) Wire Feed Rate (m/min.) 1 1 1 1 2 2 1 3 3 2 1 2 2 2 3 2 3 1 3 1 3 3 2 1 3 3 2 In the present thesis work, the work material used for present work is mild steel, the dimensions of the work piece length 300 mm, width 25mm, thickness 5mm. The chemical composition of the material is given below: Table-2.3 Chemical Composition description of the workpiece C% Mn% Si% S% P% Cr% Ni% Mo% W% V% 0.22 0.95 0.25 0.060 0.060 - - - - - Fig. 2.1 workpiece material 2.2 Equipments used: Following machines were used during my whole experiments: 1) Grinding machine Low carbon steel with the dimensions of 150x25x5 mm is prepared with the bevel heights of 5 millimeter, bevel angle of 45 0. These specimens are then welded with a root gap distance 1 millimeter. Figure shows the single V groove butt joint preparations. Pappu Kumar, Prof. Prakash Kumar IJSRE Volume 4 Issue 11 November 2016 Page 6054
Figure 2.2 Sample specimens with bevel angle of 45 0 After preparation, plates are placed on the workbench. In each placement, distance between the nozzle and workpiece and the electrode extension were 20 and 10 millimeter, respectively. The welding electrode is held perpendicular to the welding surface. is started and the flow rate of shielding gas is adjusted by using knob. The plates were welded at single pass. Fig.2.3 Grinding cutter Fig. 2.4 Workpiecs after V-Groove preparation 2) MIG 400 Machine :- Two pieces welded with the help of MIG 400 welding machine. (i) Filler metal: The filler material use for the experiment is copper coated MS material electrodes with size of 0.8 mm diameter. (ii) Shielding Gas: A shielding gas is selected for the experiments. It contains 100% CO2 Fig. 2.5 Workpiece after MIG welding Fig.2.6 MIG 400 welding machine 3) Ultimate Tensile strength measurement Tensile testing was done using ASME Section IX-2004 standards. The equipment used was a UTM Machine with a maximum capacity of 1000 kn. The welded specimen was prepared according to the procedures given in ASME Section ix-2004 and typical dimensions of the specimen are shown below in Figure 2.8. Fig. 2.7 Universal Testing Machine Fig.8 Tensile Testing specimen Pappu Kumar, Prof. Prakash Kumar IJSRE Volume 4 Issue 11 November 2016 Page 6055
2.3. Data Collection Performing the above programme nine times by varying the values of WC, WV and WFR, we collected following data: Table 2.4. Results of Tensile strength obtained from experiment SL No (Amp) (A) Voltage (Volt) (B) Wire feed rate(m/min) (C) 1. 50 15 3 50 2. 50 19 4 62 3. 50 23 5 60 4. 100 15 4 56 5. 100 19 5 70 6. 100 23 3 68 7. 150 15 5 65 8. 150 19 3 71 9. 150 23 4 73 Tensile strength KN 3. RESULTS&DISCUSSION All the experimental results are analyzed by a power full statistical tool named Minitab software of latest version 17. First of all the input parameters are defined in the software as per their corresponding value and then give the responses data to optimize. Here, the main objective of the problem is to maximize the Tensile Strenght. So, the criterion of Larger-The-Better is adopted for the optimization of Tensile Strenght. 3.1 Analysis of Tensile strength Observing all the nine experiments and the applying Taguchi method on the result using minitab-17, we can draw the following table describing the S/N ratio and mean for the tensile strength. Table-3.1 Experimental results for Tensile Strength and corr. S/N ratio and mean Trial no (Amp.) Voltage (volt.) Wire Feed Rate (m/min.) Tensile Strength S/N ratio 1 50 15 3 50 33.9794 2 50 19 4 62 35.8478 3 50 23 5 60 35.5630 4 100 15 4 56 34.9638 5 100 19 5 70 36.9020 6 100 23 3 68 36.6502 7 150 15 5 65 36.2583 8 150 19 3 71 37.0252 9 150 23 4 73 37.2665 Table-3.2 Response table for S/N ratio for Tensile Strength (Larger-the-better) Level (Amp.) Voltage (volt.) Wire Feed Rate (m/min.) 1 57.33 57.00 63.00 2 64.67 67.67 63.77 3 69.77 67.00 65.00 Delta 12.33 10.67 2.00 Rank 1 2 3 Pappu Kumar, Prof. Prakash Kumar IJSRE Volume 4 Issue 11 November 2016 Page 6056
The main effect plot for the S/N ratio for tensile strength is plotted below: Fig.3.1Taguchi Analysis: Main effect plot for S/N ratio for Tensile Strength Hence, from the graph, it can be seen that the optimum welding parameter can be obtained by points or values of parameters having the peak position in the graph. Therefore Factor levels for predictions. Table-3.3. Predicted values of parameters for Tensile Strength Parameters (Amp.) Voltage (volt.) Wire Feed Rate (m/min.) Optimum value 150 19 5 The above combination of the values of the welding parameters is going to provide the maximum tensile strength. 3.2. Anova and effects of parameters on Tensile Strength Analysis of variance (Anova) was used to determine the design parameters significantly influencing the tensile strength (response). The table shows the results of Anova for tensile strength. This analysis was evaluated for a confidence level of 95%, that is for significance level of = 0.05(6). Table-3.4. ANOVA result for surface roughness Source DF AdjSS AdjMS Spindle speed Feed rate Depth of cut F- Value P- Value 2 230.889 115.444 19.98 0.048 2 214.222 107.111 18.54 0.051 2 6.222 3.111 0.54 0.650 Error 2 11.556 5.778 Total 8 462.889 Notes: DF, Degrees of freedom; Adj SS, Adjusted sum of squares; Adj MS, Adjusted mean Squares. S= 2.40370, R-sq= 97.50%, R-sq= 90.01%, R-sq(pred)= 49.45% It can be observed from the results obtained in the table current was the most significant parameter having the highest statistical influence (P= 0.048) and the voltage(p= 0.51) followed by wire feed rate. (P= 0.650).The coefficient of determination (R 2 ) is defined as the ratio of the explained variation to the total variation. It is a measure of the degree of the fit. When R 2 approaches unity a better response model results and it fits the actual data. The value of R 2 calculated for this model was 0.95, i.e., very close to unity, and thus acceptable. Thus, it is conferred that this model provides reasonably good explanation of the relationship between the independent factors and the response. Pappu Kumar, Prof. Prakash Kumar IJSRE Volume 4 Issue 11 November 2016 Page 6057
3.3. The confirmation Test for tensile strength Since the optimal level of the process parameters has been selected, the final step is to predict and verify the improvement of the tensile strength using the optimal setting of the process parameters. The estimated S/N ratios for the tensile strength using the optimal combination were determined by Minitab- 17 software. The calculated results are shown in Table. Table No. 3.5. Confirmation test result SL NO (Amp) voltage (Volt) Wire feed rate m/min Predicated S/N Ratio Experimental S/N Ratio 1 150 19 5 37.5814 37.8419 4. CONCLUSIONS This paper has presented an application of parameter design of the taguchi method in the optimization of Mig welding operations. The following conclusions can be drawn based on the experimental results of this study: It is also found that the different parametric design based on the Taguchi method provides a simple, systematic and efficient methodology for the optimization of the Mig welding parameters (previously confirmed by many other researchers). P-values obtained for the various factors, the Based on this experiment and ANOVA analysis, it can be concluded that welding current and welding voltage are the main parameters among the three controllable factors (welding current, welding voltage, wire feed rate) that influence tensile strength during Mig welding. The reason behind this is that among the different value is minimum for the welding current i.e. 0.048 followed by that for welding voltage (0.051). When we looking for higher tensile strength, welding current (150 amp.), higher welding voltage (19 volt.) and higher wire feed rate (5m/min.) can be employed to get optimized result. 5. REFERENCE 1. Sapakal.s.v, Telsang work on Parametric Optimization of MIG Using Taguchi Design Method (2012). 2. SivasakthivelK et al. works on Optimization of Parameter in MIG bytaguchi Method (2015). 3. ChavdaSatyaduttsinh P., DesaiJayesh V, PatelTushar M.investigationA Review on Optimization of MIG Parameters using Taguchi s DOE Method (2014). 4. S. V. Sapakal¹, M. T. TelsangParametric OptimizationofMIG Using Taguchi Design Method (2012). Pappu Kumar, Prof. Prakash Kumar IJSRE Volume 4 Issue 11 November 2016 Page 6058