Friends all welcome. Today's article will be useful to those who are just beginning familiarity with welding, or are going to do it here. And we consider such an important and interesting topic, why welding pulls and deforms the metal. Many ever heard such expressions, drawn from the welding welding led, why is this happening?
To illustrate an example, we take a few two-corner irons 8mm thick, plate 140 to 150mm and thickness 2mm profiled pipe 20 to 40mm and 2mm thick. And these glands we impose welds.
To begin, we shall weld thick corners and see what happens. We see that if we put it on a flat weld joint of the pipe plane, it will be visually evident that the corners slightly pulled up to the side of the weld.
Further impose several joints on the plate and see the result. The plate was spun and distorted.
Now an experiment with the profile pipe. Impose on its surface from 40mm five transverse welds. Look what will happen? Even such a thing as a profiled tube arched upwards towards the welding seams.
All these examples have occurred for the following reasons. The result was a shrinkage of weld metal. In simple terms, this phenomenon occurs in such a way, when there is a welding process, the weld pool and the already formed her seam have a greater temperature. The molten metal cools, it becomes more dense and sharp decrease in the volume. Tensile stress occurs in the adjacent metal parts with a seam. In simple terms the weld as it pulls close to her parts of metal, pulling the blanket over himself! That's in a nutshell, you can explain this phenomenon, because of which the welding and deformation occur.
Sorry for a spoiled piece of pipe? Me too. And so we turn it up the hump and impose more than 6 joints-1 greater cham on the opposite side. Then all the joints grind to the bottom of the pipe, certainly when they are cool. And it happened a miracle, our pipe again straightened up and it can be used on pulmonary structures irresponsible. We have used the knowledge of the deformation of the weld itself to good use.
We will not be part of today's article describes how to avoid the negative effects of deformations from svarki- this topic is extensive, and we will consider it in future articles. Just today, this educational program about the deformation of the welding.