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hewittfarm
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    Fri Mar 08, 2013 7:52 am

I wonder if the wire speed at a given voltage affects the weld penetration. I like to use slower wire feed speeds that recommended on my Lincoln 256 cover because it gives me more time to direct the weld but do not want to weaken the weld bond by doing so. It seems to mt novice ears that some of the lower WS are otherwise the same on the other welding respects. What is the theory of wire speed and are the recommended ones on the welder designed for maximum bead size and speed or do they relate to weld quality?
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On a MIG, where you have a constant voltage, increasing wire speed is equivalent to increasing the amperage, and therefore the total power going into the weld.

One would think, then, that faster wire speeds would lead to more penetration, and there is a little bit of truth to it, but, with higher speeds, you have to move faster and spend less time with the heat in any one place, so it kind-of offsets the effect.

Those recommendations on the cover are just starting points anyway. Few machines work dead-perfect at those settings, and you should adjust until you find what works best for you. If you're producing a good looking weld without much spatter to clean, you likely have the penetration you need for a strong weld. MIG usually tells you when you're doing something wrong by giving you obvious clues, like undercut or excessive spatter.

Steve S
Alexa
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    Mon Dec 31, 2012 10:07 am

Hewittfarm.

Your Power Mig 256 should be a CV (constant voltage) machine. So the amps are increased as the wire speed is increased and visa versa, even those it is not one-to-one ratio.

There are many welding variables in welding. Some major and many minor.

One approach to understanding these variables is to actually make a welding procedure as you weld. You might obtain a WPS (Welding Procedure Specification) which is usually an one or two page chart that lists all major variables and some minor ones. Your chore is to understand all the variables on the WPS ... probably around twenty to forty.

Some of them are simple and straight forward. For example: the type of material, the thickness of the material, etc.. Others will need a bit of blogging and/or googling around. But the important thing is that as you begin to understand the variables, you will understand what you are doing as you weld. This will allow you to speed up the learning process immensely.

Alexa
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