ESAB Miniarc 150, Инструкция по эксплуатации, Страница: 26 / 48

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SECTION 3 OPERATION
When making practice butt welds it is wise to check the results occasionally. Where elaborate testing equipment is not
available, this may be done with a hammer and vise.
CAUTION SHOULD BE OBSERVED IN HANDLING WELDED PIECES OF METAL, SINCE WELD HEAT ABSORBED BY THE
METAL IS INTENSE AND CAN CAUSE SERIOUS BURNS.
Grip a short, welded piece with the weld just above the jaws of the vise. Hammer it in a direction that tends to open the
bottom, root side of the weld, in the manner shown in Figure 3.19. A good weld will not break under this test, but will bend
over. If the weld breaks, examine it to determine the cause. If there are a large number of holes (the weld looks spongy) it
is porous.
Figure 3.19 Weld Test
This is probably due to holding too long an arc. If there are bits of slag in the weld perhaps the arc was too short or the
electrode was manipulated incorrectly thus permitting molten slag from the electrode coating to be trapped. This is quite
likely to happen on a V joint made in several layers and calls for thorough cleaning between layers. Perhaps on breaking it
will be found that the original surface of the bevel is still evident. That means that it was not melted and the cause is quite
likely to be found in too fast a travel speed or insufficient heat.
TEE AND LAP JOINTS
The &her bast type of weld, the fillet weld, is used for making tee and lap joints, For this type of welding, no special prepara-
tion, other than squared edges, is necessary. Typical welded tee and lap joints are pictured in Figures 3.20 and 3.21 respec-
tively.
Figure 3.20 Tee Joint