Fat-Fab.com
02-10-2007, 10:19 AM
Words in welding many times have deferent meanings dependant on the part of the country you hale. That is why the AWS (American Welding Society www.aws.org) was founded 1919 to form a standard of terminology. So no asked again “is that a strong weld?” that question is almost nonsensical when talking AWS talk. So instead we should will that weld have elongation equal to the parent metal, or “will that welded joint have a proper amount of ductility so it won’t snap” and “will that welded joint have proper tensile strength”.
So the three main factors of a welded joint are ELONGATION, DUCTILITY and TENSILE.
Elongation refers to the amount of energy needed to elongate a material.
Ductile is a measurement of materials plasticity.
Tensile is the energy needed to elongate to deformation as well to the breaking point.
As you can see the three are interrelated and one can not talk about one with out consideration of the others.
The question posed below is a good example of the misunderstood terms or misused terms that are so familiar to us from the welding industry. I have no wish to embarrass this member it is just a very good example.
Chrome-Moly frame? Heat treated prone to cracking?
Hi, I am in a debate over a bike frame. I want to ad a few tubes in the rear of the frame to brace it to prevent flex. It is made of Chrome-moly and was heat treated from the manufacture. The Manufacture and others say that it can't be welded, if it is it will crack for sure. I know that thin walled chrome-moly tubing if I don't heat treat it before welding (as long as its around 70F or more) it will hold and not crack. Heat-treating is for the thicker stuff.
I'm not sure cause this is already heat treated from the manufacture. So?
This member talks of “heat treating” before welding; the practice of heat treating before welding is so limited in practice as to be no existent. What the questioner is more than likely asking about is “pre-heating” the joint, used to bring all materials to be welded up to a consistent temperature, as well to remove any moisture, further used to slow the cooling process so as to remove post weld cracking.
What the member is also asking about is post weld “stress relieving”. A process of bringing the cooled welded joint back up to a temperature, hold it for a time and allowing it to cool at a known rate.
So the final answer to his questions is to weld with ER80-s2 allow to cool and stress relieve.
So is this a proper use of this forum? Should I address things like this in the future? Or should the fat guy from Alaska just go back to counting snow flakes?
TJ
So the three main factors of a welded joint are ELONGATION, DUCTILITY and TENSILE.
Elongation refers to the amount of energy needed to elongate a material.
Ductile is a measurement of materials plasticity.
Tensile is the energy needed to elongate to deformation as well to the breaking point.
As you can see the three are interrelated and one can not talk about one with out consideration of the others.
The question posed below is a good example of the misunderstood terms or misused terms that are so familiar to us from the welding industry. I have no wish to embarrass this member it is just a very good example.
Chrome-Moly frame? Heat treated prone to cracking?
Hi, I am in a debate over a bike frame. I want to ad a few tubes in the rear of the frame to brace it to prevent flex. It is made of Chrome-moly and was heat treated from the manufacture. The Manufacture and others say that it can't be welded, if it is it will crack for sure. I know that thin walled chrome-moly tubing if I don't heat treat it before welding (as long as its around 70F or more) it will hold and not crack. Heat-treating is for the thicker stuff.
I'm not sure cause this is already heat treated from the manufacture. So?
This member talks of “heat treating” before welding; the practice of heat treating before welding is so limited in practice as to be no existent. What the questioner is more than likely asking about is “pre-heating” the joint, used to bring all materials to be welded up to a consistent temperature, as well to remove any moisture, further used to slow the cooling process so as to remove post weld cracking.
What the member is also asking about is post weld “stress relieving”. A process of bringing the cooled welded joint back up to a temperature, hold it for a time and allowing it to cool at a known rate.
So the final answer to his questions is to weld with ER80-s2 allow to cool and stress relieve.
So is this a proper use of this forum? Should I address things like this in the future? Or should the fat guy from Alaska just go back to counting snow flakes?
TJ