Shafts: 4140 vs 4150?
Shafts: 4140 vs 4150?
(OP)
For large pump shafts (12" diameter range) the published specifications on 4140 and 4150 appear to be very close in terms of yield, etc. IF material costs were equal, does anyone have a preference for either alloy in terms of machining or durability in service? I can't seem to find a quantitative difference so I'm asking you experts!
Thanks for the advice!
Thanks for the advice!
Keep the wheels on the ground
Bob
showshine@aol.com





RE: Shafts: 4140 vs 4150?
Obviously as the difference in carbon content gets bigger the differences btw the steels will be greater also.
Nick
I love materials science!
RE: Shafts: 4140 vs 4150?
So in a real world situation, looking a nominal 110ksi ultimate and 85ksi 2% yield (this was the spec I found for 9" bar stock) the 4150 would be just a bit harder to machine, (not heat treated after machining) and a little bit stronger. Any way to define a percentage difference in strength? From what I can see cyclic endurance should be the same.
Thanks!
Keep the wheels on the ground
Bob
showshine@aol.com
RE: Shafts: 4140 vs 4150?
<opinion follows>
If you are'nt concerned about heat treated shaft then there wont be a significant difference in these materials. The additional carbon really plays a role when Quenched and tempered.
nick
(keep the wheels in the dirt you mean)
Viva Pro-Le-Ralliat
RE: Shafts: 4140 vs 4150?
RE: Shafts: 4140 vs 4150?
Doesnt the sulfur also impact the fatigue performance? (or is it completely iin solution?)
nick
RE: Shafts: 4140 vs 4150?
Nick - I try and keep at least ONE wheel in the dirt ...usually the fronts are just hanging there when the car is really hooked up!!
Keep the wheels on the ground
Bob
showshine@aol.com
RE: Shafts: 4140 vs 4150?
Alex
RE: Shafts: 4140 vs 4150?
(Rally drivers do it sideways)
nick
RE: Shafts: 4140 vs 4150?
(Rally drivers go one at a time.... there's 24 of us on a 4/10 mile dirt oval at 130mph - all trying to be in front)
Keep the wheels on the ground
Bob
showshine@aol.com
RE: Shafts: 4140 vs 4150?
There is some argument that the leaner alloy steels such as 4140 and 4150 give desirable compressive surface stresses after quenching and tempering. I have doubts about this because of the generally high tempering temperatures to bring these steels back to the strength level required for optimum machinability and fatigue resistance. The tempering acts as a stress relief and any benefits from compressive surface residual stresses are negated.
RE: Shafts: 4140 vs 4150?
I'd spec 4340 for most of the work (except corrosive) but the competition uses the cheap stuff.
I'd like to mention that everytime I get into EngTips it's VERY educational - Thanks!
Keep the wheels on the ground
Bob
showshine@aol.com