Annealing drill rod.

[Dasher]

 Hi all, hoping for a bit of help. I've been trying to anneal a piece of drill rod, already cut and flattened, so it had been heated once already by me, I then heated it to critical, and let it sit in the forge , closed up to cool. After this it was still quite hard to file etc, so after reading Steve Sells article on the subject, I reheated it to critical, let it air cool, then reheated it to sub critical and let it cool in vermiculite. After this, a file just skated across, as if fully hardened, any advice would be appreciated. Note: temperatures were not precise, I just used magnetic/ non magnetic to achieve critical, and sub critical was an estimate based on colour, but was approaching critical.

[Irondragon Forge ClayWorks]

What type of drill rod are you using?

[Dasher]

To be honest IF&C I really don't know.

 

[Irondragon Forge ClayWorks]

I believe what you have is called sucker rod here in the states. If you have the end that connects to more rod this may help to id it.

 

[Dasher]

Thanks Irondragon, that is helpfull, but it doesn't quite identify my stuff, those charts seem to be for actual rod, whereas my stuff is actually drill pipe, which is called drill rod here, and the indentifiers don't apply, but it has narrowed down my search a bit.

[arkie]

Dasher, it appears that you have drill pipe as opposed to sucker rod, as Irondragon alluded to.  Drill pipe has a bore for fluid transmission whereas sucker rod (sometimes called drill rod in some countries) is a solid rod.  Here in the U. S., drill pipe is used to drill wells and other types of boreholes, whereas sucker rod is used on a surface pumping unit along with a downhole pump to extract fluids to the surface.  Drill pipe can range in size from around 2" O.D. to over 6" O. D.  Some pipe can have rather thick walls.  If you cut drill pipe lengthwise and flattened it, my hat's off to you!

In some drilling operations here in the U. S. tubing is used instead of conventional drill pipe due to it's thinner walls, smaller diameter and flexibility in directional drilling.  If you cut and flattened the pipe it may actually be what we call tubing.

All that being said, it may be quite a search, possibly including contacting the vendor themselves, to find out what the composition of the material is.  It usually ranges from mild steel to special alloys for temperature, strength, corrosion resistance, deep depths, high pressure etc.  If you go to search for vendor information it would behoove you to accurately describe if you are working with drill pipe, tubing or sucker rod, as the compositions range widely.

As a starter, just google "drill pipe" and go through the results to narrow your search.  You might also google "oil field tubing" to get info on that tubular product.

https://www.google.com/search?q=drill+pipe&oq=drill+pipe&aqs=chrome..69i57.3878j0j7&sourceid=chrome&ie=UTF-8

This may also help; looks like this particular drill pipe is 4140.

https://www.spmetals.net/aisi-4130-alloysteel/4130-alloysteel-pipes-tubes-tubing/alloysteel-pipes-type-aisi-4130-drill-pipes/

[Dasher]

arkie, I suspect you are right, most probably drill tube, about 3" o.d., about 4mm wall thickness, probably thicker before wear, as the tube got very thin towards the end where most erosion had happened, so probably started as 1/4" or 6.5 mm thick, for that thickness it was a bit tough to cut, and I initially tried to flatten it with oxy/ acet, and that was tough going trying to break it's back, but not so bad in the forge where I could get a better spread of heat.

[Frosty]

Drill string, the pipe used to turn the drill bits at the bottom of the casing is often an abrasion resistant steel, the joints are hard faced, often with high carbon mig wire and tungsten carbide granules streamed into the weld puddle. Doing this was one of my first jobs during my brief career on the slope. 

Anyway, forget joints they'll just eat tools, tungsten particles will ding your anvil and hammers. I don't know anybody working with a drill "rod, pipe," joint's body. The string we used on the foundation exploration drill rig wasn't in the same league, we drilled shallow holes, rarely more than 150' so out drill strings didn't suffer wear like an oil rig. I used our damaged drill rod for fab all the time but like I say it's a different world of abuse and steel tough enough to take it.

Frosty The Lucky.

[arkie]

Dasher, from your description of the dimensions of the steel, it is almost certainly tubing. Now, tubing can also be made of various compositions including alloys similar to drill pipe and drill collars. Some may indeed be hard to work with. As Frosty mentioned, avoid the connection ends due to the ways they are made. 

Correction, I erroneously called the drill pipe I referenced 4140... should have said 4130...typo.

FYI, drill pipe and some tubing is made from three pieces; the tubular part and two ends, one male (the "pin") and the other female(the "box). The pieces these days are joined by friction welding, where the joints are shoved together and spun at very high RPMs.

Good luck working with that stuff!

 

[Dasher]

Thanks Arkie and Frosty, I think you nailed it between you, the tube is used for drilling the type of jobs Frosty mentioned, and the collar is a double ring push fit by the look of it, and very hard, the finish is almost chrome like, except for the heavily eroded ends, I'll check out 4130 treatment and see if I can do a workaround that way, thanks.

[Dasher]

Well I went back and tried again, basically repeating what I,d already tried, but playing closer attention to [estimated] temperatures, almost identical results, the heat then forge cooling is marginally softer than the cooled in vermiculite method, and can be drilled ok with care,[ only small diameter so far, 3/16:], but it is still very hard to file and do other similar things. All the info I've read seems to indicate I need better temp monitoring and control, and there is not a lot of detailed info on annealing 4130 in a simple home forge set up.If I've missed something and someone can point it out, I'd appreciate it. The job is doable as is, but a LOT harder and more power tools.

[arkie]

Dasher, see if there might be any identifying marks on the tubing that may indicate the manufacturer.  It's usually stamped on the pin or box end if you have that.  If not, you might try to contact several tubing manufacturers down under and see it you can worm your way into their engineering departments.  They might give you an insight into the composition of the tubing.  Sounds like it may be an alloy for severe service rather than simple 4130 steel.  If you are successful in contacting any tech folks, be sure to give them any and all info you have and assure them that you are not the competitor, just a blacksmith trying to figure out how to work with and treat some tubing.

[Dasher]

Will do, Arkie, still dark here ATM,if I get any good info, I'll post it.

[Dasher]

I followed the advice given and chased up some info, got some good help, but the guy from the actual supplier never rang back, but , what I have seems to be a hammer adapter inner tube, and generally they seem to be made of 1040, so my annealling methods should of worked if I got my temps right, I might use this stock for something else as what I planned to do needed a knife like edge, and it seems 1040 is not the best edge keeper.

[Frosty]

Is it part of a "down hole hammer" or a sub to make up to one? Can you link m to a pic?

Annealing thick tubing can be problematical it cools faster than you'd think, sometimes enough to keep it from softening. Normalizing tubing can be really difficult cool air circulates through it so it wants to cool too fast. 

Maybe try plugging the ends with Kaowool to prevent a free flow of air. Remember it MUST have a safe way to equalize pressure so no solid plugs! Kaowool is a safe way to block the ends.

1040 should be easy to soften enough to drill let alone file, just run the temper colors past blue should do it.

Frosty The Lucky.

[Dasher]

Pic attached, the collar has 1 o ring external, with 2 o rings internal at the end we are looking at. The material softened enough for machinability I think, I drilled a couple of 3/16" holes easily enough, but you could feel the bit working when drilling dry, but a file makes little impression, my annealing attempts so far have been solely heating to non mag, and either in vermiculite cooling, or in forge cooling with opening blocked with fire bricks, no other tempering etc,  appreciate your input Frosty.

I got this stuff a while back to make some wood lathe tooling, before I'd made a forge or manufactured an anvil/ hitting block. I initially split the tube with a grinder, then using oxy/ acet, tried to flatten it, even with a large heating tip, I couldn't get a large enough area hot enough to hammer it flat,, [ask my shoulder], so it went on the back burner till I got my forge up and running, then it flattened easily enough.

[Frosty]

Boy, not a tool I've seen but having  o  ring seals inside and out makes me wonder if it's not a down hole sampler. The outer tube would be the cutting tool and strong enough to withstand the forces applied to it, whether down hole hammer or hydraulics from the surface. The double o rings would secure the sample retainer tube. A lighter maybe split barrel a sample cut by the cutter outer barrel would be contained by the inner barrel. There would be a one way retainer so the sample couldn't fall out easily when the sampler is withdrawn. 

It reminds me a LITTLE bit of how the core barrels we used were set up. 

Just a WAG. Once again my opinion is unpolluted by specific knowledge. It's one of my specialties you know. 

Frosty The Lucky.

[Dasher]

For what it's worth the piece I'm using came off the far end, around a metre long, slightly thinner wall tapering to knife edge from erosion from working, you can just make out the reducing step down on the far end.

[Frosty]

Hmmmm. I'd like a look at what it was, not that I intend to ever even touch a drill rig again but this makes me wonder. We didn't do any down hole drilling but we did some continuous sampling and what you describe sounds like it might be . . . Or?

Frosty The Lucky.