Int J Performability Eng ›› 2016, Vol. 12 ›› Issue (2): 155-172.doi: 10.23940/ijpe.16.2.p155.mag

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Orbital TIG Welding Process Parameter Optimization using Design of Experiment for Satellite Application

M. KARTHIKEYAN1, VALLAYIL N. A. NAIKAN2, R. NARAYAN1, and D. P. SUDHAKAR1   

  1. 1 Liquid Propulsion System Centre (LPSC), Indian Space Research Organisation (ISRO), Bangalore-560008, INDIA.
    2 Reliability Engineering Centre (REC), Indian Institute of Technology (IIT), Kharagpur-721302, INDIA.

Abstract:

This paper highlights the optimization of Orbital Tungsten Inert Gas (OTIG) welding process parameters by Design of Experiment (DOE) using Taguchi method forwelding of stainless steel of 6mm diameter and 0.7 mm thickness for satellite propulsion feed system. This proposed methodology identifies the optimum parameters for welding and brings out the significance of the individual parameter, combination of any of the two parameters (interaction effect) using Taguchi method by linear model analysis of Signal to Noise (SN) ratio and means verses input parameters. Detailed experiments were carried out and optimum parameters are arrived. Further these are tested by different methods to evaluate the strength required for intended application. This ensures sound and reliable weld joint. The optimum levels of these parameters thus developed are being followed and no call for any rework is reported thereafter. By varying the input parameters (current, RPM, gap between electrode and the job), the weld penetration level or weld quality has been studied in several 6mm diameter tube specimens andthe significance were studied and discussed in the test results.The Factorial Factor design is followed for minimum of 27 (three parameters and three levels=3×3=27) samples for this experiment. By further fine tuning the experiment, the optimized values achieved are current 18.35 Amps, electrode rotation 10 rpm and gap between electrode and job 0.8 mm. The weld specimen quality was verified in accordance with the user's quality standards and found satisfactory. This approach is easy to develop and easy to use that assures the best combination of parameters required for Orbital TIG welding which yield strong and defect free weld joint for Satellite application.


Received on October 26, 2015, revised on January 29, 2016
References: 29