- Thread starter adi
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As with 4130 some like a er80 type filler as it is a better match strength wise (on paper) while er70 fillers are an undermatch with regards to strength. Dilution with the base metal is going to alter things but for something like a roll cage, tube chassis etc keeping the joints (relatively) ductile is a good thing as they are always going to be a stress riser no matter how well they are made.
T45 is better than 4130 with regards to weldability and elongation but a decent sized weld made with an er70 type filler is going to be more than strong enough (weld size compensates for the undermatched strength) and less brittle than a weld made with an er80 type filler
No harder or much different to weld than mild steel but the differences will be more apparant when machining it
T45 is better than 4130 with regards to weldability and elongation but a decent sized weld made with an er70 type filler is going to be more than strong enough (weld size compensates for the undermatched strength) and less brittle than a weld made with an er80 type filler
No harder or much different to weld than mild steel but the differences will be more apparant when machining it
Hi All!
hotrodder, T45 tubing should not really be welded using ER80 TIG filler! It is a Carbon/Manganese steel, not a Chrome/Moly steel! T45 tube is stronger than 4130 Chrome/Moly tube which technically needs pre and post weld heat treatment, however, general consensus seems to indicated that heat treatment is not needed on thin wall tubing as used in motor sport frames, roll cages etc.
adi, you should be able to get the filler wire from any welding supply shop or off the 'tinternet very easily! Welding Titanium is also very easy, keeping the weld free of atmospheric contamination is NOT! I welded Titanium for a number of years on military aircraft and the easiest way is in a vacuum chamber! Never had a problem, however this is not really practicable for most situations! You need to keep the atmosphere away from the weld and the surrounding area both whilst welding and also for a period of time for the weld to cool down past it's temperature for it to absorb O2. This means lots of argon gas purges to protect the hot metal while it cools! Fortunately, the metal itself will tell you if it's been contaminated with Oxygen by turning blue, Blue is bad! White is worse!
Basicly, your looking to achieve a weld with the same colour as the parent metal, we were allowed a slight 'straw' tint of colour away from the actual weld to be acceptable.
Don't forget the inside of the exhaust will also need to be protected from atmospheric attack as well!
Regards
hotrodder, T45 tubing should not really be welded using ER80 TIG filler! It is a Carbon/Manganese steel, not a Chrome/Moly steel! T45 tube is stronger than 4130 Chrome/Moly tube which technically needs pre and post weld heat treatment, however, general consensus seems to indicated that heat treatment is not needed on thin wall tubing as used in motor sport frames, roll cages etc.
adi, you should be able to get the filler wire from any welding supply shop or off the 'tinternet very easily! Welding Titanium is also very easy, keeping the weld free of atmospheric contamination is NOT! I welded Titanium for a number of years on military aircraft and the easiest way is in a vacuum chamber! Never had a problem, however this is not really practicable for most situations! You need to keep the atmosphere away from the weld and the surrounding area both whilst welding and also for a period of time for the weld to cool down past it's temperature for it to absorb O2. This means lots of argon gas purges to protect the hot metal while it cools! Fortunately, the metal itself will tell you if it's been contaminated with Oxygen by turning blue, Blue is bad! White is worse!
Basicly, your looking to achieve a weld with the same colour as the parent metal, we were allowed a slight 'straw' tint of colour away from the actual weld to be acceptable.
Don't forget the inside of the exhaust will also need to be protected from atmospheric attack as well!
Regards
My bad Rodofgod. These sort of discussions often centre around the undermatch in strength (on paper) when using an er70 filler on thin wall 4130 and T45. Got tunnelvision on this aspect and filler chemistry didn't even enter my thoughts
Adi, to add to what Rodofgod said about Ti welding... while it is lovely to weld the filler can have a tendancy to 'stick' to the puddle which can catch you out until you're expecting it- tends to be most noticable if you catch the edges of the puddle with the filler, feels as though there's a magnetic attraction. The filler needs to be kept within the gas shield at all times (weld colouration applies to the end of the filler too), caught me the first time i welded Ti, kept pulling the filler out of the gas shield when it 'stuck'
Hello guys, holy thread resurections batman, and all that jazz. Just a couole of quick questions for you re the T45. As Rodofgod pointed out 4130 should always be heat treated, is this not the case with T45? I presume not as it's used a lot in wels in cages. If it should there's a lot of cars out there with dodgy roll cages.
Just curious as I would like to make a few parts for my car.
Also does T45 come in plate form? If not what is the equivalent steel to use in this case where I want to make a bolt in harness bar?
Just curious as I would like to make a few parts for my car.
Also does T45 come in plate form? If not what is the equivalent steel to use in this case where I want to make a bolt in harness bar?
ER80 doesnt mean its CrMo..........it could be 1%Nickel or something else. Its the suffix that determines the Chemistry so the Bs are CrMo and the Cs are Ni and the Ds are MnMo
So it would be OK with the Nickel bearing but maybe not with the CrMo
Having said that I would go with A15 as opposed to ER70S-6 as its a little bit more ductile than the S6.
Many years ago I got involved withe the Ford Rally cars and they were using 312 to build their roll cages. I suggested A15 and they wouldnt believe me. We made some tests with A15 and they were good.
Someone read that 4130 is CrMo and needed preheat and PWHT........which is does when its 10 times thicker.
I think upto that point all of the Roll Cages were welded with 312..........it might have been me that changed all that to the A15
So it would be OK with the Nickel bearing but maybe not with the CrMo
Having said that I would go with A15 as opposed to ER70S-6 as its a little bit more ductile than the S6.
Many years ago I got involved withe the Ford Rally cars and they were using 312 to build their roll cages. I suggested A15 and they wouldnt believe me. We made some tests with A15 and they were good.
Someone read that 4130 is CrMo and needed preheat and PWHT........which is does when its 10 times thicker.
I think upto that point all of the Roll Cages were welded with 312..........it might have been me that changed all that to the A15
