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wheresmejumper
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Dairywall or high purity stainless is often welded fillerless,but amps,prep,purge and skill all need to be perfect
wheresmejumper
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High purity is a grade of stainless thats normally welded using automated orbital welders.by button pushers not actual welders
Richard.
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Y
You can weld 304 without filler.
Richard.
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Polisius are probably top dogs for those things and yes perfect results from minimum skill. More a large production tool and very expensive too. I saw those closed heads used for tube to tube butts welding on big heat exchangers. They then swapped to an open style similar head with wire feed for the tube to flange. Impressive things and I can see the appeal for turning out perfection at speed but looked bloody boring to be doing day in day out.
Thought it might be Inconel but there are loads of grades.......which one?They use inconel for exhausts,sounds expensive and prob is
Inconel 625 is the usual suspect for those with deep enough pockets but F1 pockets are almost bottomless so maybe using some other (even proprietary?) nickel based super alloy these days, exhausts are changed for different circuits and typically disposible i.e. lifed for X hours/races. Some F1 exhaust fabricators use (or at least used to) filler wire, i'm sure i've seen vids of wire being used and somewhere on the forum is a photo i took of an old '90s F1 exhaust which makes it very obvious that wire was used
Welding carbon steels autogenously with manual TIG usually results in porosity (the filler wire contains several elements to 'mop up' oxides hence double or triple "deoxidised") and other problems with 'posher' steels. With aluminium and it's alloys if no/not enough filler wire is used the weld often can't resist shrinkage stresses as the pool freezes resulting in solidification (hot) cracking. The heat treatable flavours are even more prone to this as the alloying elements usually increase sensitivity to hot cracking... the 6xxx series for example rely on magnesium silicide as a hardening phase which needs diluting with an AlSi or AlMg filler wire to keep the Mg2Si out of it's most crack sensitive region
Pretty much all flavours of austenitic (non magnetic) stainless weld nicely without wire. Whether the results are good enough from a 'strength' or corrosion resistance* POV depends on various other things... what's it used for, expected service life, over engineered or not, excessive undercutting from a nervous welder etc
* filler wires are often 'over alloyed' for various reasons
Welding carbon steels autogenously with manual TIG usually results in porosity (the filler wire contains several elements to 'mop up' oxides hence double or triple "deoxidised") and other problems with 'posher' steels. With aluminium and it's alloys if no/not enough filler wire is used the weld often can't resist shrinkage stresses as the pool freezes resulting in solidification (hot) cracking. The heat treatable flavours are even more prone to this as the alloying elements usually increase sensitivity to hot cracking... the 6xxx series for example rely on magnesium silicide as a hardening phase which needs diluting with an AlSi or AlMg filler wire to keep the Mg2Si out of it's most crack sensitive region
Pretty much all flavours of austenitic (non magnetic) stainless weld nicely without wire. Whether the results are good enough from a 'strength' or corrosion resistance* POV depends on various other things... what's it used for, expected service life, over engineered or not, excessive undercutting from a nervous welder etc
* filler wires are often 'over alloyed' for various reasons
Richard.
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Very. It's a very good at moving the hot gases through quicker because of its ability to retain heat. It's very strong and can compete with other choice materials on strength at half there thickness so can be kept very light. The expense is mainly down to its high nickel content. Super alloy, very strong very corrosion resistant.They use inconel for exhausts,sounds expensive and prob is
Richard.
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625 I believe Al
I know some specific 'exhust alloys' of Ti have been developed but they're still very temp limited compared to nickel alloys. Upper service limit for the common flavours of Ti are a little over 400°C, the high temp alloys get over 600° but i think 800ish is about as good as it gets and that might(?) not be for alloys that have the formability needed to make exhausts stuff
Nickel alloys are so heat resistant they end up lighter i.e. can use stupidly thin wall tube and still have enough creep strength that'll survive insane temps. The nineties exhaust i mentioned was under 1mm wall thickness on the straight sections, with the stretching that goes on when bending tube wall thickness is probably under 0.5mm in places these days
matt1978
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The operators are probably already class 1 welders. Maybe not so much for dairy pipe but other areas where Orbital is quite prevalent, the semi conductor industry all the welders are usually all "proper" welders first and foremost but on all of the system pipework they usually forbid manual welding as the quality and repeatability isn't good enough. Also the welds look amazing but everything has to be 100% in order to get the acceptable results. Level of penetration within the Butt weld has to be exact and has to be controlled via the internal gas purge pressure.
It looks easy and to be honest it is when you get into it, but there is a lot of work to get to the point where it's churning out perfect welds all of the time.
wheresmejumper
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I only know a few operators Matt,but they are by no means top class with a normal torch.a 5 day course qualifies you to weld pretty much any 1 pass butt,chemical plants etc
the monotony and boredom of standing back as it welds has most grabbing a shield again.
the monotony and boredom of standing back as it welds has most grabbing a shield again.
Rrunnach
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I've worked with a few hands who have worked global. Multi coded using various processes, "actual welders" who also have many years experience orbital welding.
matt1978
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I did it for about 6 months whilst they were building the then new Intel factory near Dublin.
At first it's great, no spatter, no getting hot and sweaty, don't even need a welding mask for the enclosed heads but it did get a bit monotonous. All the lads operating the AMI Orbitals and the Kajun micor bore stuff were all class 1 welders as they were contractors and had to move from site to site as and where the work took them.
At first it's great, no spatter, no getting hot and sweaty, don't even need a welding mask for the enclosed heads but it did get a bit monotonous. All the lads operating the AMI Orbitals and the Kajun micor bore stuff were all class 1 welders as they were contractors and had to move from site to site as and where the work took them.
