Using annealed 4140 without heat treat
Using annealed 4140 without heat treat
(OP)
Is there ever a case where using annealed 4140 without heat treatment (185-225 BHN) would work for the pinion of a gear set if the stresses are low enough? (12 ksi beam stress, 42 ksi contact, 60 rpm, 2 inch pitch Ø)





RE: Using annealed 4140 without heat treat
could simply use 1050 normalized or some
other steel? Yes you could use it, but
is would not be cost effective.
RE: Using annealed 4140 without heat treat
You might want to consider ductile iron (65-45-12), free machining steels (12L14)or silicon-bronze/aluminum-bronze alloys. Just make sure that the pinion gear material & condition you select is a compatible match for its mating gear.
This company produces a very nice, continuous cast ductile iron bar: http://www.dura-bar.com/
RE: Using annealed 4140 without heat treat
RE: Using annealed 4140 without heat treat
RE: Using annealed 4140 without heat treat
Establish the minimum hardness material combination which will sustain your power requirements and select the most cost effective materials. Do not incur heat treatment costs unless you need to. The more you mess around with materials, the bigger the problem if anything goes wrong.
RE: Using annealed 4140 without heat treat
a good reason to use gears non HT is to reduce noise. We combined non HT helical pinions with extended addendum, and the noise reduction was dramatic. we ran this pinion against both aluminum gears and brass gears.
(This was in a noise reduced breast pump assy! Apparently the boys in the office were picking up strange noises during lunch hour.)