An Analytical Approach towards the Interactive Behavior of the Confounded Parameters of Submerged Arc Welding Process for Mild Steel Plates

Abstract

This paper deals with the Study of the Interactions of the Confounded Parameters of Submerged Arc Welding Process for Welding Mild Steel Plates of Higher thicknesses. Here the thickness of the plate is more than 10 mm. This experimental study was conducted at the workshop of Indian School of Mines, (Dhanbad). For this study MEMCO semiautomatic welding equipment with constant voltage rectifier was used. Specifications are as below:

Input voltage supply- 380/440 volts

Welding speed Trolley-30 to 1200 mm/min

3 Phase,50/60 Hz cycle. Air cooled

Wire feed speed-100 to 8000 mm per minute.

Output current 600 amps

Wire diameter -2 to 5 mm

Duty cycle 100%

Open circuit voltage 56 Volts, 35 Kva

Flux hopper capacity 12.5 kg

Deposition rate- 4 to 6 kg/hr

Wire flux ratio-1: 1

Flux used: ADOR Auto melt

GrII AWS/SFA 5.17(Granular flux)

Test Piece: 190mm X 90mm X 12mm

Weld position flat

Electrode positive and perpendicular to the plate.

The SAW process has been chosen for this application because of the complex set of variables involved in the process. Submerged arc welding (SAW) is a high quality, very high deposition rate welding process commonly used to join plate. SAW is usually operated as a fully mechanized or automatic process, but it can be semi-automatic also Submerged arc welding provides a purer and cleaner high volume weld which is also faster than traditional welding methods. The SAW process is much more critical because of its application in welding critical parts, equipments and machinery which have huge economic and social implications. Welding parameters: current, arc voltage and travel speed all affect bead shape, depth of penetration and chemical composition of the deposited weld metal. Because the operator cannot see the weld pool, greater reliance must be placed on parameter settings’.

In this study the parameters among current, arc voltage, and travel speed were varied and then the readings for penetration, bead width, metal deposition rate and time were taken. Welding parameters were noted during actual welding to determine the fluctuations. The same procedure is repeated many times to achieve more accurate results. On the bases of these readings graphs were plotted between the parameters to study the interactions of the parameters with each other. The main objective being to identify the main input factors, to determine the interactions amongst the input factors and finally to establish the optimum settings for the input factors the response output being weld bead parameters.