What type of steel is weldable?

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tornitore45
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What type of steel is weldable?

Post by tornitore45 »

I am new to the welding, have a small flux core wire arc welder.
I seem to recall that only low carbon steel can be arc welded, NO leaded steel.
Is that correct?
How high the carbon before welding become problematic?

I have an L bar from a bed frame that, judging from the way it hacksaws, has more carbon the 1018, could it be welded?
Thanks
Mauro Gaetano
in Austin TX
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Dave_C
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Re: What type of steel is weldable?

Post by Dave_C »

Mauro,

You are correct on the leaded steel, such as 12L14, does not weld properly.

As far as the bed frame, I would think you could weld it if you clean it real well.

Small wire feed welders are nice, I have one, and they can do a lot of small jobs. Clean is very important!

There are other forms of steel such as some of the stress proof steels that don't lend themselves to welding as well. There are links to welding data that can tell you what will and will not weld with each method of welding. Just do some quick searches.

Dave
I learn something new every day! Problem is I forget two.
hammermill
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Re: What type of steel is weldable?

Post by hammermill »

pick some some new known steel to learn with. starting with unknowns will have you pulling your hair out in fustration.. not to mention the offered bed fram steel can be anything or everything as it is a lowcost product
made from lots of recycled steel kind of like cheep rebar.

have a metal shop cut some 3x3 pieces of flat plate say 1018 and practice on these. it will improve coffidence as you overcome mistakes.
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Harold_V
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Re: What type of steel is weldable?

Post by Harold_V »

Carbon in and of itself doesn't render material such that it won't weld. A good example of the problem is considering 4130 as opposed to 4140. 4130 was developed such that it could be torch welded without issues. Step up just .10% more in carbon and that is no longer the case. There are acceptable procedures for welding 4140---I've witnessed it in defense work--but they pretty much demand proper pre and post handling in order to prevent cracking of the material. Thus, I would suggest, at least in the chrome moly series, that .30 carbon content pretty much defines the upper limit of material that can be welded successfully.

Bed frame often has high carbon content. It isn't just junk steel--it is prepared so it can be heat treated, for maximum strength without having a frame that is difficult for the consumer to handle. Likewise, rebar isn't just junk steel, in spite of it being made from remelt in many cases. It tends to have a reputation that is not deserved. It must meet specifications, such as being capable of being welded when required. Rebar is available with that requirement, certified to be low in carbon so it will not harden in the welding process. Common rebar must be capable of being bent cold.

The house and shop I built in retirement has consumed many tons of steel, as I built using Rastra, a leave-in-place foam form. #4 & #5 rebar was used in both vertical and horizontal runs @ 15" centers. One wall required #5 rebar be welded to a 10" wide flange beam.

Harold
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tornitore45
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Re: What type of steel is weldable?

Post by tornitore45 »

That makes a lot of sense Harold. As always there are reasons to anything. Bedframe designers had to assure strenght and lightness, that is why I got so much good use of it for various fixtures and even a cutting tool. Re-bar is one of my favorite stock for handles and levers is inexpensive (but not cheap) available at HD and bend well, something I observed but did recognize as being a requirement as obviously it must be.
Mauro Gaetano
in Austin TX
hammermill
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Re: What type of steel is weldable?

Post by hammermill »

got me looking at rebar specs this line was of intrest thanks wiki

Without special consideration the only rebar that is ready to weld is W grade (Low-alloy — A706). Rebar that is not produced to the ASTM A706 specification is generally not suitable for welding without calculating the "carbon-equivalent". Material with a carbon-equivalent of less than 0.55 can be welded. (AWS D1.4)

always something of interest as a kid we built lots of headgates with rebar and learned it was faster to use the cutter over a torch which yielded indifferent results. higher grade spec alloy is a much nicer beast.

always learning
Russ Hanscom
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Re: What type of steel is weldable?

Post by Russ Hanscom »

The simple, but not always universal solution, to welding higher carbon steels is preheat. Frequently something that cracks when welded at room temp will behave acceptably when preheated to several hundred degrees.
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Re: What type of steel is weldable?

Post by redneckalbertan »

Russ Hanscom wrote:The simple, but not always universal solution, to welding higher carbon steels is preheat. Frequently something that cracks when welded at room temp will behave acceptably when preheated to several hundred degrees.
Post heat and slow cooling can also help with alloys prone to cracking. To slow the cooling rate wrap in fibreglass insulation or other non flammable insulating material.
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Harold_V
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Re: What type of steel is weldable?

Post by Harold_V »

hammermill wrote:Without special consideration the only rebar that is ready to weld is W grade (Low-alloy — A706). Rebar that is not produced to the ASTM A706 specification is generally not suitable for welding without calculating the "carbon-equivalent". Material with a carbon-equivalent of less than 0.55 can be welded. (AWS D1.4)
Being aware of that, and not having the foresight to purchase the proper rebar, before welding the pieces in place on my building project, I cut a piece from the lengths that were to be used. The piece was heated to redness (in sunlight), then quenched in water. If it was going to be troublesome, that should have exposed any issues. As it turned out, the rebar was still soft and malleable--so I determined it was safe to weld, which I did, using 7018. Keep a good thought! :-) That's the best I had at my disposal at the time.

Harold
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Re: What type of steel is weldable?

Post by PeteH »

Mauro... you didn't mention which brand of wire-welder you had; if it's Horror Fright or an equivalent, the roll of wire that came packed with it may not be very high quality. I've read postings -- maybe on this forum, I don't recall -- that said the stuff is more trouble than it's worth, and that it's be best to get yourself a roll of Lincoln or other recognized brand wire.

Also, the stuff that came with my HF welder was .035", and the fellow at the local welding shop said that that would overwork the welder and wouldn't penetrate; that I should use .030". Since I already was buying some, there was no motive for him to "bend the truth".

Take this for what it's worth. No point fighting the tool, too.

Pete
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tornitore45
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Re: What type of steel is weldable?

Post by tornitore45 »

Pete, I have exactly the Horror Fright model and heard the same story.
I used it only once with wire that came, between the bad wire and the green operator the bead came out orrible.
Still a friend of mine that had a bit more experience layd a much better bead which mean skills are still important.
Anyway I am sure buying a quality wire of the right size.
Mauro Gaetano
in Austin TX
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