heat affected areas

[simmo]

so I'm working my way up to structural welding but have a query

say for example I'm welding 350 grade steel with a 150amp mig and .9mm gas mig wire with an Argon bottle. at full power

if I crank up the amps, wirespeed slow and lay a good weld..... no crackling etc and very very slow pass

does the fact the workpeice is literally glowing bright red (10cm long fillet) effect the original intergity of the two materials I've just welded together? when it stops glowing red and has cooled down will I have destroyed the strength properties of the 350 grade steel?

-simmo

 

[patreusch]

it will make the area strong but brittle as with most mig welding

 

[clem dog]

Would this be considered "spray transfer" then?

 

[shenion]

Spray transfer normally occurs at 175 amps and above. The wire does not touch the weld pool.

 

[Sparkey]

Yes, i found it works a treat (for me that is) around 200 amps...but to go into spray your travelspeed has to be quite high too, you have to find the balance between too fast and too slow...( wirespeed 7.9 on my oerli)
You got it now clem? (just ask me i can go on for hours about this!)

 

[malcolm]

350 is an Australian spec for structural mild steel?

What thickness are you welding - seems like an odd technique there - why are you doing it that way?

If the steel is too thick for the welder then you might be better off preparing the steel with a nice V shape and doing multiple passes using normal settings. A V effectively reduces the thickness of the steel.

A low wire speed will reduce current, so if you are struggling for current in the first place that's unlikely to be helpful.

If I've got the wrong end of the stick please beat me with it.

 

[snowcat]

Without a thickness its impossible to gauge, personally a little 150 amp MIG would be the last piece of kit to start welding structural beams together...

Spray as spray has already mentioned is usually high (Volts) and fast travel speed.....

I wouldn't really recommend your technique......

 

[Sparkey]

Without a thickness its impossible to gauge, personally a little 150 amp MIG would be the last piece of kit to start welding structural beams together...

Spray as spray has already mentioned is usually high (Volts) and fast travel speed.....

I wouldn't really recommend your technique......

Yes, it's around 34.6 if my memory's correct...(with the settings i described above)