Effect of welding parameters on the shape and size of weld

The main mode of arc welding parameters are:

• size, density, polarity and welding current generation;
• arc voltage;
• welding speed;
• cross-sectional area (diameter) wire (electrode).

More Options:

• thickness and composition of the electrode surface;
• Departure wire;
• position of the electrode and welding products;
• grain size of the welding flux and its composition.

From these parameters depend on the shape and size of the seam, its chemical composition. In shape and size also affects the weld welding technique.

With the increase of welding current increases the depth of penetration and weld width is almost unchanged.

With the increase of arc voltage rises sharply joint width, depth of penetration is reduced. It also decreases and convexity (height gain) seam. When welding with direct current (in particular, reverse polarity) joint width will be much greater than when welding with alternating current with the same voltage value.

With increasing welding speed decreases joint width and the depth of penetration at first increases (up to a speed of 40-50 m / h) and then decreases. When the welding speed of more than 70-80 m / h are possible undercuts on both sides of the joint due to insufficient heating of the base metal.

With decreasing diameter of the wire (ceteris paribus) increases the current density in the electrode, which leads to an increase in the depth of penetration and the convexity of the joint, but it reduces the width of the seam. Thus, with decreasing diameter of the wire can get deeper penetration with a constant current intensity or the same penetration at lower amperage.

With increasing emission of wire diameter of 3 mm from the current supply mouthpiece reduces the depth of penetration that can lead to baffle edge in the seam. Increasing the departure of wire 5 mm in diameter from 60 to 150 mm has no effect on the shape of the weld.

See also:
Defects in welded joints and seams

Weld seams and joints:
geometry of the weld seam
weld classification
the effect of welding parameters on the shape and size of weld