Hard to TIG Steel ?

[Lanmanb4]

Are there steel alloys that are harder to TIG then others?
I went to the local steel yard and asked for some steel to
practice TIG on .. I have gotten steel from him before ..
Only this was different then the usualt steel , but still looked like
good ole steel to me .. not galvanized or anything ..
So I get some outta the scrap bin .. ask him how much he wants ..
and give him like 5 bucks .. and go him happy ..
Funny thing though? After I gave him the five .. he looked over and said " TIG huh? " Now he knows I MIG .. and I figured he was just curious that
now I am trying to TIG ... but then when I got it home .. and tried to
TIG It .. wow .. hard to heat .. weld pool looked funny ...
No I did only wipe it off .. my mistake I know .. but still it seemed different .
Which is what brings me to my question ..

Once it cools .. I'll brush it off and take pictures of it TIG'd and not .. and post them ..

Any ideas pop into anyones mind at this point ??
I once heard the phrase "oil impregnated " cant remember if it was in regards
to steel or not ..


Randy

[zapster]

ahhh post and we'll see whats up..

the best thing to learn tig with is stainless steel 300 series..
you can fuse it all day and learn the method of heat before ever having to add filler..
thats a whole 'nother trick...

...zap!

[orphan68]

Oil impregnated would be oil lite bushings made of brass, also graphite impregnated. As for welding steel to be different between the grades, I don't know. Sorry

Tony

[Lanmanb4]

I brushed it off and was looking at the welds.. and they are undercut .. and then it dawned on me where I have seen this kind of metal before.. at least by the appearance .. and thats muffler pipe material .. only in this case its thicker and not pipe .. i'll take some pictures ..

[Lanmanb4]

Ok .. heres a piece of the metal ..

Is steel with a higher carbon content harder to TIG?

[zapster]

Originally Posted by Lanmanb4

Ok .. heres a piece of the metal ..

Is steel with a higher carbon content harder to TIG?

what exactly am i looking at?

and no not really..

...zap!

[Lanmanb4]

You are lookin a piece of that steel ..
Hey could be I just need to clean / brush it better ..
But it still make me wonder about whether different grades of steel might
be tougher to TIG then others ..
Besides I am trying to get the prize for posting useless , meaningless questions .. LOL ..

[zapster]

Besides I am trying to get the prize for posting useless , meaningless questions .. LOL ..


i'm afraid you have a ways to go my friend...

...zap!

[ZTFab]

That pic looks like standard ol' hot rolled steel....welds like shnit with the scale still on it. It will undercut badly and give very inconsistent beads if you leave it on...which is what happened to you.

Either grind of the scale or next time you go to the steel yard, ask them if they have either cold rolled steel or hot rolled P&O(pickled and oiled) in their scrap bin. Those have no scale and will weld great with very little surface prep.

BTW, the "muffler pipe" you are talking about is usually aluminized tubing. That piece looks too dark to be aluminized.

[riley mcmillan]

I have tig welded a lot of hot rolled steel with the scale on it and didn't have much trouble with it. I just weld it quick and use a good filler rod. I think where you can get in trouble is to linger too long. Also just fusing it can cause bubbles. Once it is contaminated, you gotta grind it all out and start again. When I really want it nice, I clean off the scale with murietic acid and rinse well.

[orphan68]

Steel with a higher carbon content should go through a normalization process. The higher the carbon content, the more brittle it will get with the heat. That is why steels like D2 L6 and such are used for cutting blades and not recommended to be welded on unless they have gone through some preheat/post-heat process. Has anyone ever seen a die break after being welded without pre/post heating? Ugly!!!!!!
Tony

[fun4now.]

yep i would say its the scale from the hot roled steel, hit it with a flap disk till its nice and shiny and it will weld real nice. im not saying you cant weld threw it but if you are new, clean it off and try again. it will weld sweet. big difference between MIG and TIG , you just gotta be clean to TIG. any thing you TIG should be clean and shiny. flap disk the heck out of it hit it with some asitone and go to town.

[Lanmanb4]

ok .. will give that a try ... and see how it goes ..
Thanks for all the nice info ..

[Lanmanb4]

Well ... really quickly this evening ..
I took a piece of that alleged hot rolled steel .
and milled the surface smooth and took off more then
enough . prolly like .025" worth ..

Then I ran 3 short TIG beads ..
Took a picture after ..

Another interesting thing about this steel .. is the heat does not
conduct along the piece of steel anything like the other pieces I have ..
I wonder if a different amount of thermal conduction is an attribute of hot
rolled steel as well ?? Thoughts .??

It didnt undercut this time ..
and it did seem to flow better .

I have another question .. I TIG left handed ..
and I have been , up till this last session, TIG'n from left to right.
But tonite .. due to where I set this up at quickly .. I TIG'd from foward to back , uhmm towards me .. filler coming in from the right ..
Is this ok? Anyone else ever do it this way ? I like how it felt but wasnt
sure if it was acceptable .. Comments ??

Thanks ..

Randy

[zapster]

hot rolled dont turn blue... not like that...
tool steel will however..

take a file to it and see what happens...

...zap!

[zapster]

whatever way your comfortable with is whats ok for you...allways tig twards you never away..

...zap!

[Lanmanb4]

ok will do .. and I think the flash might have helped bring that color out a little more then it truly was ..
Would / could tool steel be in a " channel " shape ???
Oh .. not sure if this helps .. but when I milled it .. the surface was
pretty darn shiney ... and the scarf was quite hot ... ( hope that was the right word for the pieces of metal that come flying off when you mill it )

Randy

[zapster]

well its not hotrolled..

its some sort of alloy for sure..

tool steel can come any way you want it..

but it will cost ya...

still looks like either A-2 or oil hardining tool steel...

...zap!

[Lanmanb4]

Well if it is , then maybe I should stop wasting it with welding practice ..

If I have a hardness tester .. I could always put a piece in the kiln and fire it up and then let it cool by air and do a piece and dunk it in oil .. see if they get harder .. LOL ..

[zapster]

Originally Posted by Lanmanb4

Well if it is , then maybe I should stop wasting it with welding practice ..

If I have a hardness tester .. I could always put a piece in the kiln and fire it up and then let it cool by air and do a piece and dunk it in oil .. see if they get harder .. LOL ..

go get some stainless steel and get it over with..

its the easiest mat. to practice on...
fuse it and abuse it it will take it..

...zap!

[ZTFab]

Well, there goes my theory!!!

[ulav8r]

Hot rolled that has the scale removed will turn blue. The color is the result of oxides formed during heating of the steel. That shade of blue means the steel reached a temperature of about 600-650 degrees. Any carbon steel will react similarly.

[awright]

The cuttings from your mill is called swarf.

"SWARF Fine metallic filings or shavings removed by a cutting tool." American Heritage Dictionary.

But I know nothing about relative tiggability (?) of steels.

Have fun.

awright

[Lanmanb4]

Originally Posted by awright

The cuttings from your mill is called swarf.

"SWARF Fine metallic filings or shavings removed by a cutting tool." American Heritage Dictionary.

But I know nothing about relative tiggability (?) of steels.

Have fun.

awright

Thanks... I actually knew that .. but for the life of me couldnt remember it at the time I was doing the post . .. LOL

[zapster]

Originally Posted by awright

The cuttings from your mill is called swarf.

"SWARF Fine metallic filings or shavings removed by a cutting tool." American Heritage Dictionary.

But I know nothing about relative tiggability (?) of steels.

Have fun.

awright

i call'em chips..
and when they are that hot and they come in contact with you face..well that sucks

...zap!