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HammackWelding
05-03-2005, 06:05 PM
Guys I have a problem I am hoping someone on here could help me with. I have been turning some bushings to weld into a skidder grapple, to fix the worn out pins and bushings. The problem i am having is that I usually just turn the things from cold roll, but I did not have anything in the shop big enough for this job. I went to a machine shop and picked up a piece of 4.5 inch shaft to bore out, and the only thing they had was 1045 so I took it. Once I chucked it into my lathe it bored fine, but when i went to face off the ends, and turn down the outside diameter it acts as if it has hard spots in it. and I mean HARD!!! its eating tool bits like they are plastic, I have tried to turn it on my 16 inch southbend as well as my 12 inch atlas and same with both lathes, I even chucked a piece that had not been bored and just started turning it down, and it would turn fine, then hit a spot it couldn't is this common? what could be the cause of this. I am using regular tool bits, but they are the best that MSC had to offer. I have a welding business and usually turn my own bushing etc.. but usually turn cold roll or bronze, and I have never seen anything like this. thanks in advance for any help. ~Jackson

WJHartson
05-03-2005, 06:18 PM
1045 steel has 45 points of carbon and is hardening when you cut it due to the heat building up in the piece during machining. It would cut a lot better with carbide tooling once it is hardened. You have to keep it cool when turning and drilling to help stop the hardening. Are you using any coolent?

I'm sure you know that when you weld 1045 you have to preheat and post heat to stop it from cracking.

Hope this helps.

Joe

precisionworks
05-03-2005, 07:46 PM
As Joe said, carbide (or cermet inserts if the hardness is high, above 46HRC).

If you can find 12L11, or 11L44, both are free machining because of the lead content. Same cautions apply regarding welding.

------------------
Barry Milton

wierdscience
05-03-2005, 09:27 PM
Yep like said carbide,but you can also fix your problem,it will just take some time.

Put the parts in a steel drum and build a good hot charcoal fire in it,(red heat)burn it at least 4 hours then let cool naturally.

That should anneal any hard spots in it.So long as you use coolant when machining you shouldn't have anymore trouble.

BTW,it the same alloy used in cylinder rods of the hard chrome variety so 7018 might be a good choice for welding.

madman
05-04-2005, 11:45 PM
Those shafts you picked up were probably cut with an abrasive cut off saw. High heat. Once theres .30 carbon content it gets hard when heats directed its way. I suggest cut off a half inch from the end and then face it. Let me know how it went. Good Luck

rklopp
05-05-2005, 12:41 AM
I'm on a case hardening kick tonight. See http://bbs.homeshopmachinist.net//Forum1/HTML/011724.html

Is this shaft piece case hardened? Sometimes 1045 shafts are hardened using a scanning induction coil that is turned on an off to harden only select bands along the length of a part, e.g., splines or bearing journals.

ronsmith100
05-05-2005, 12:51 PM
I am missing something here.
1) you said it bored easy enough
2) you said it was hard to face
3) you said it was hard to turn.

So I assume it is hard cased but not hard core.
Maybe I misread something but it sounds case hardened to me. I dont know how you could heat up 1045 to case hardend it without getting the inside hardened also. So maybe it was only heated on the outside once? Stange.

wierdscience
05-05-2005, 11:24 PM
<font face="Verdana, Arial" size="2">Originally posted by ronsmith100:
I am missing something here.
1) you said it bored easy enough
2) you said it was hard to face
3) you said it was hard to turn.

So I assume it is hard cased but not hard core.
Maybe I misread something but it sounds case hardened to me. I dont know how you could heat up 1045 to case hardend it without getting the inside hardened also. So maybe it was only heated on the outside once? Stange.</font>

This is all from memory so you get what you pay for here.Induction hardening is used to produce the hard skin on parts in most commercial processes.The material or part is placed inside a coil of copper tubing which has chilled water running through it for cooling.High frequency(200-200,000 cycles) and moderately high current is passed through the coil.The skin of the coil carries the current and the water keeps the coil from melting.

The high frequency induces histerisis in the surface of the part or material being treated and causes it to heat rapidly.Once the desired temperature is reached the current is switched off and the part or material is quenched with water or oil.

The higher the frequency used the more shallow the case and the more rapidly it is applied.The lower the frequency the thicker the case and the slower it can be applied.The lower frequencies can even melt steel.

The local Army ammo plant had an induction furnace that would bring 5x5" steel billet from room temperature to forging heat in minutes,a really impressive sight.

A lot of 1045 is used for hydraulic cylinder rods.It is induction case hardened about .090" deep on diameters 3" and up.This is done so the rod has great rigidity to resist bending under non-concentric column loads,but allows a soft core to make it tough as well.

In addition 1050 is also used in induction thru hardened form for the same purpose except it is mostly seen in loads where the rod is under tension.It has a thru hardness of 48-52 rc al the way through.

If you ever buy any rod you will notice that the 1045 is cheaper than the 1050 due to processing times in it's mfg.