Mild Steel

[roofman]

Whenever i bring 2 pieces of steel together (thin) by just melting the two ime a little concerned the metal goes brittle with the process....Do i always need to use filler or is the "fusion" method consided a decent joining process in terms of strength??

 

[mtt.tr]

Depends on what it is to be used for.

 

[roofman]

Depends on what it is to be used for.

yea your right i failed to point that bit out just general brackets ect with no heavy loading really and maybe a bit of 5-8mm stuff

 

[eSCHEn]

Autogenous is the posh term.

Stainless yes, works well.

Mild no, you want a bit of filler as its composition contains stuff that helps wet and remove contaminants.

 

[Piero]

I don't know.

He does say it's only a non load bearing bracket.

Why not ????

 

[Tinbasherdan]

I don't know.

He does say it's only a non load bearing bracket.

Why not ????

It pays to get in the habit of doing the job properly, no matter whether it's load bearing or not

 

[Piero]

Not wanting to get into an argument.

But why is it only a proper job if it has added filler rod.

The job simply does not warent it.

On the opposite side of the scale. Over kill is not a proper job

 

[Richard.]

Mild steel autogenous welding (no filler) doesn't work. You will nearly always get porosity. The tig filler adds purity to the weld pool exactly as eschen said. This is why gas welding rods don't work for tig. Stainless yes autogenous welding is acceptable but steel you NEED a filler .

 

[roofman]

thanks lads...i think this question and debate is now concluded

 

[eSCHEn]

Anyway. Pictures or it didn't happen ^_^

 

[roofman]

Anyway. Pictures or it didn't happen ^_^

LOL you lot get enough pics off me....

 

[Piero]

Maybe I read the post wrong.

But I thought the guy asked if he always needs to use filler wire/rod

First reply asked what for. (best replay as yet me thinks)

He went on to say for general brackets with no heavy loading.

For reasons explained by others. Filler rod gives the best results.

But that was not said question.

carbon steel DOES gets fused together in industry without filler wire.

It all depends what it's used for.

A quick Google seach comes up with arguments for both sides.

But again. They all get lost in the argument and every one stops seeing the question.

So it can be done. It does get done. It's fine to do so.


To give an excample, I am at the moment (as well as other things) restoring my myford super 7 lathe,

I had cause to cover up machined faces to a part, prior to the the part going into my blasing cabinet.

a scrap bit of sheet steel 1mm thick got the job, there was a 45 deg bend needed on said sheet, I had the tig to hand and an other bit of scrap sheet got tiged to the main flat sheet (NO FILLER WIRE)

it got bolted to the main part, plus other verious rubber plugs, and it went in to my cabinet for blasting.

the weld done its job, the sheet steel is now scrap, and the part has had a lovely coat of epoxy mastic.

is there anyone on this forum who could honestly say I should have used filler wire for said job???????

 

[Piero]

its getting there whoop whoop

 

[Richard.]

Well ok it's stuck it together fine. But the correct way to tig weld steel is with a filler rod. The op is asking why the weld is weak the answer is it needs a bit of filler for the reasons above. I don't see it to be a debatable thing. If he'd of stuck it together as you did and the weld was not weak he wouldn't of started the thread asking the question.

 

[Piero]

Richard

I still think your missing my point!!!!!!

you said, and I quote "the correct way to tig weld steel is with a filler rod"

says who???? correct for what ??????

Its the better way of doing it yes, I grant you

the better way of doing some thing is NOT always needed.

The op did NOT ask why the weld is weak, he asked why it seems brittle.

he went on to ask, ."Do i always need to use filler or is the "fusion" method consided a decent joining process in terms of strength??"

He got a very good reply from mtt.tr "Depends on what it is to be used for."

the op went on to say "just general brackets ect with no heavy loading really and maybe a bit of 5-8mm stuff"

I simply dont agree you have to ALWAYS use filler wire,

as said, IT DEPENDS ON WHATS ITS FOR!!!!!!!!!!!

ps, I dont recall having said I glued and metal togeather, (stuck) why attempt to be little it, the weld I did, with out the use of filler wire was perfectly fine for the job in hand.
thats my point.

 

[Tiggy_dorset]

Simply put, with an autogenous joint, the joint has sacrificed/used a bit of the parent material from both pieces. The joint will never be the same thickness/strength as the parent material or a welded joint, but it will be glued together. Fine for non-critical and non-load bearing aplications in my opinion. I have done it many times with stainless without issues, although I canot truthfully say if I have ever tried it with mild steel when I think about it, so cannot comment on the porosity/contamination issues which have been raised.

 

[Richard.]

Richard

I still think your missing my point!!!!!!

you said, and I quote "the correct way to tig weld steel is with a filler rod"

says who???? correct for what ??????

Its the better way of doing it yes, I grant you

the better way of doing some thing is NOT always needed.

The op did NOT ask why the weld is weak, he asked why it seems brittle.

he went on to ask, ."Do i always need to use filler or is the "fusion" method consided a decent joining process in terms of strength??"

He got a very good reply from mtt.tr "Depends on what it is to be used for."

the op went on to say "just general brackets ect with no heavy loading really and maybe a bit of 5-8mm stuff"

I simply dont agree you have to ALWAYS use filler wire,

as said, IT DEPENDS ON WHATS ITS FOR!!!!!!!!!!!

ps, I dont recall having said I glued and metal togeather, (stuck) why attempt to be little it, the weld I did, with out the use of filler wire was perfectly fine for the job in hand.
thats my point.

Weak/brittle whatever!!!!! He's asking why and the answer is because he's joined carbon steel with a tig arc and no filler. The result is usually porus welds. Now please tell me when are porus welds acceptable. I think your missing the point here because if roof man didn't find those welds to be a concern in his mind whether they be brittle weak or porus he would not of started the thread asking the question. And depends on what it's for doesn't answer it at all. He asked is fusion alone on mild steel considered a "decent " joining process. No it's not. Will it hold things together? Maybe but so does blue tack. We are talking welding here and if the risk is porus welds it's not acceptable. Simple.

 

[roofman]

 

[Richard.]

http://www.google.co.uk/url?sa=t&so...21043/&usg=AFQjCNHXpQuMXS46qG17PKPmoLlbA5oOsA
This thread might be devoted to using the wrong type of filler but the reasoning is the same. Gas welding rods don't offer the dioxidising properties needed to Tig weld in the same way that no filler wire doesn't either. Dedicate Tig filler is needed because the process produces oxides and as Tig welding is a 100% inert shielded process oxides are going to compromise the weld with porosity.

 

[Piero]

you seem to have yr head locked in the mode of if it is not 100% right it is no good.

as tig welders, most do strive to master the art, every thing needs to be spot on the produce that perfect weld,

yes we all know this, you are not teaching nothing new

but surly you have heard the term, "fit for purpose" ????

I am not even going to argue if a weld, done on clean carbon steel will or will not produce porosity.

so we have this autogenous weld, done on carbon steel, even with some porosity.

are you trying to say it is NOT fit for ANY purpose?????????????.



as I said, there is a disscusion going on on an other welding forum, regarding this very topic,

one guy is saying, he works in a factory that builds cookers, he is claiming that on some parts NO FILLER wire is used, (brackets etc)

Are all these cookers no good then, should they be sent back????