plug weld การใช้

• The specimens were machined such that plug weld was centered on the width of the specimen .
• No spalled paint exists at the plug weld and for a short distance each side of the plug welds .
• Close examination of the plug welds showed the existence of herringbone patterns near the slag and voids in welds .
• Thus the fracture likely initiated from fatigue sharpened cracks originating from slag and void in the plug welds .
• Development and key problem of friction plug welding