Heat treatment
Heat treatment
(OP)
If I wanted to heat treat a shaft made from 4140 with the major O.D. @ 2.5"... what would be the ideal temp/amount of time and proper quenching method be?... My gears that I tested have a Rockwell of 62 on the "C" scale... So if anything I'd like to match the hardness or be a little under that of the gear...It'll need to handle decent torque loads (I know this isn't the best material to use, but it's all I had). I know I'll have to stress relieve or temper it to bring it down etc... Any thoughts Ideas wouod be highly appreciated...
Also, how much will this material expand after the heat treatment... And how would I compensate for this?
Also, how much will this material expand after the heat treatment... And how would I compensate for this?





RE: Heat treatment
RE: Heat treatment
RE: Heat treatment
I have a lot of experience with heat treating 4140
and it will not safely get over R/c 42
If you haven't made it yet I would use 4340 HT to R/c 48 and nitride to 60C
There are a lot of other options for shaft material, I wouldn't lock in on any one until you have all your engineering requirements worked out. Run the numbers it is cheaper then putting something in and seeing if it works..
Cheers
I don't know anything but the people that do.
RE: Heat treatment
On the old shaft and and gear they both Rockwell 62 on the "C"...
So I figured if Iget it close to the original etc.. These aren't running gears.. More or less the shaft is splined and slides in the center of the gear...
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Do you guys think that if I heat treat or carbon pack it and then temper, and finally Nitride the shaft that it would be sufficient to maintain for a while...
Let me make note to what this is going to be used for... so you guys can get abasic Idea of what I'm dealing with..
I'm building a Jeep basically a Crawler... Something that won't see more than 30mph.. Maybe... It won't be a daily driver for reasons listed above..
Also the larger Diameter will have the back side bored to 1.760" I.D. so the thickest part on the larger diameter will be 334". (from top of the tooth to edge of the I.D.... and from the root of the tooth to the I.D. is .254" thick).. The main shaft/shank O.D. is 1.6265"...
RE: Heat treatment
RE: Heat treatment
RE: Heat treatment
RE: Heat treatment
Swall... why not have the splines nitrided?... Will it make them too brittle?
RE: Heat treatment
RE: Heat treatment
I use Nitride for wear factor only and because you can get a minuscule growth from it I have saved some under sized shafts. In the long run a nitride surface is the way to go and if you say there is not a lot of tooth load and you are just worried about wear, then you have options to case harden 8620 or nitride 4140..
But I will bow to the experts as all my experience is from the manufacturing side and I am not sure what the books say.
Cheers
I don't know anything but the people that do.
RE: Heat treatment
RE: Heat treatment
I need help in that area as I am often running in the dark as I have designed a few PSRU's (power supply reduction unit) for experimental aircraft and I have a feeling that I could manage some of my harmonics inside the transmission with heat treat and variable materials.
I will get into that later I don't want to hi jack this thread....
Cheers
I don't know anything but the people that do.
RE: Heat treatment
RE: Heat treatment
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