6150 vs 4340 vs 4140 vs ?
6150 vs 4340 vs 4140 vs ?
(OP)
Hi,
I'm having some issue selecting material and I wondered if anyone had any suggestions. The application is essentially a large snap/latch ring which gets squeezed down in diameter somewhat agressively, and needs to spring back to it's intial state. Say ring size OD ~ 4.25, ID ~ 3.625, 2" long.
My initial knee jerk reaction to material was an oil-quenched and tempered 6150 to about 45-50 HRc range (~ 190-210 ksi yield if I'm not mistaken) I have some experience with this material and it seems to behave quite well for these applications, but it is proving to be tough to source the material for these sizes. It's not impossible, but it isn't ideal.
Thus, I have been looking into trying out something we can get ahold of easier like a 4140, or possibly 4340. I've estimated a stress state around 160 ksi, and I'd like a bit of breathing room so I was targeting the 190 ksi yield...
I'm concerned about embrittlement in the 4140 as it looks like I need a temperature around 800°F which is right on the verge of temper embrittlement (as I understand it), but it is easier for me to get. Conversely the 4340 seems like a better choice due to inherent resistance to TE, but I don't know about availability here.
Is my thinking at all correct? Are there some materials I am unaware of or overlooking for good spring tempering properties?
Thanks for any help!
I'm having some issue selecting material and I wondered if anyone had any suggestions. The application is essentially a large snap/latch ring which gets squeezed down in diameter somewhat agressively, and needs to spring back to it's intial state. Say ring size OD ~ 4.25, ID ~ 3.625, 2" long.
My initial knee jerk reaction to material was an oil-quenched and tempered 6150 to about 45-50 HRc range (~ 190-210 ksi yield if I'm not mistaken) I have some experience with this material and it seems to behave quite well for these applications, but it is proving to be tough to source the material for these sizes. It's not impossible, but it isn't ideal.
Thus, I have been looking into trying out something we can get ahold of easier like a 4140, or possibly 4340. I've estimated a stress state around 160 ksi, and I'd like a bit of breathing room so I was targeting the 190 ksi yield...
I'm concerned about embrittlement in the 4140 as it looks like I need a temperature around 800°F which is right on the verge of temper embrittlement (as I understand it), but it is easier for me to get. Conversely the 4340 seems like a better choice due to inherent resistance to TE, but I don't know about availability here.
Is my thinking at all correct? Are there some materials I am unaware of or overlooking for good spring tempering properties?
Thanks for any help!





RE: 6150 vs 4340 vs 4140 vs ?
RE: 6150 vs 4340 vs 4140 vs ?
RE: 6150 vs 4340 vs 4140 vs ?
Can you upload a sketch of the part geometry? I'm having difficulty understanding what form the raw material would be in, meaning sheet, plate, bar, tube, etc. In general, you're thinking is along the right lines, spring steels instead of 4140 that is tempered at too low a temperature.
RE: 6150 vs 4340 vs 4140 vs ?
Could you work with pieces cut from plate? That might help availability.
You might want to look at some of the higher ductility tool steels. that might get the properties that you need.
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Plymouth Tube
RE: 6150 vs 4340 vs 4140 vs ?
I've considered making it from flat/strip stock, but it's outside the scope of what we deal with typically, and this is pretty thick stuff. I'm sure it's doable, but we turn and mill for the most part.
RE: 6150 vs 4340 vs 4140 vs ?
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RE: 6150 vs 4340 vs 4140 vs ?
It's not that 6150 is unattainable, my question is more regarding whether I can 'get away with' 4140 or 4340.
I'm up in Canada, so unless I expedite the shipping, we typically end up with many weeks for delivery of material when we order stuff like this from the states.
That being said, if you folks think that 6150 is the proper material for such a part, then it's worth waiting or paying the $$. It's the only 'spring steel' I've ever worked with for a machined part and it's served me well in the past.
However, if I can get similar properties out of a 4140 or 4340 without too much trouble or worry, that is considerably easier and quicker for me.
By the way, thanks to all for all the input! :)
RE: 6150 vs 4340 vs 4140 vs ?
RE: 6150 vs 4340 vs 4140 vs ?
RE: 6150 vs 4340 vs 4140 vs ?
You might check with Scot Forge as to availability of rings or blanks in your size. I would always go with a rolled ring if possible though we use a lot of forged blanks.
http:/
http://www.scotforge.com/sf_products.htm
RE: 6150 vs 4340 vs 4140 vs ?
If nothing else, I have a few more places to source the material from if need be.
Thanks!
RE: 6150 vs 4340 vs 4140 vs ?
RE: 6150 vs 4340 vs 4140 vs ?
http://www.pennsylvaniasteel.com/flexor.php