Effect of recycled flux over mechanical properties of A36 steel in submerged arc welding

Abstract

The objective of the current research is to analyse the feasibility of utilising welding slag as flux material in Submerged Arc Welding (SAW) of A36 steel. The amount of welding slag incorporated with virgin flux is varied from 20 to 50 percent in weight at an equal interval of 10%. The material welded with virgin flux and slag mixture of different proportion is tested for hardness, tensile and impact properties along with its soundness through radiography and ultrasonic testing. Hardness, tensile, yield and impact strength of the weld decreases with incremental inclusion of slag in SAW flux. Up to 30% slag additions provide optimum results where as 40 and 50% slag addition causes detrimental weld quality. Radiography and ultrasonic testing confirms the defect free weld samples welded with less slag addition, whereas welds performed with higher slag addition possess internal defects. Based on the weld quality and cost of weld materials, it is suggested to use waste slag up to 20–30 wt % with SAW flux wherein any deviation from this level will deteriorate either quality or profitability. The study favours usage of slag in the flux and contributes for reduction in the overall slag generation.

Keywords

• saw
• recycled slag
• virgin flux
• mechanical behaviour
• quality aspects