>i'm interested in any research or information on the long-term wearability of

>carburized parts versus induction hardened parts. specificly, carburized

>C-1019 (and any C-1018 through C-1025) versus induction hardened C-1050 (and

>any C-1045 through C-1055).

>

>

>thanks,

>jack wenger

>

Hello, Jack --

A couple of thoughts on carburizing vs. induction hardening:

* If your carburize, you can run carbon content at the surface up to

whatever you need; 0.8% carbon should be no problem. You can also get

carbon added to the entire surface of the part, except where you might

choose to stop it off, with copper plating, etc. Depth of carburizing is

controllable, but effective depth of carburizing in the range of 0.030" to

0.060" is common.

* The hardness of a martensitic case depends on the carbon content, but

there is a point of diminishing returns somewhere near 0.5% carbon.

Theoretically, the harder the better, as far as resisting wear.

* Induction hardening typically produces depths of hardening from about

0.50" to 0.10", but greater or lesser depths can be achieved. With

induction hardening, the issue may boil down to the ability to successfully

heat the surface. If the shape is complex, you may have problems.

* You'll probably want to temper the steel after either operation, just

a touch, to stabilize the structure. Something like 350F for an hour.

* If the application allows lubrication, either will work. In the

automotive business, camshafts and crankshafts are typically induction

hardened, while transmission gears are typically carburized. Shape of the

surfaces being hardened is probably the single most important factor in

making these decisions.

* If the nature of the application mandates continuing unlubricated

abrasive wear, you're into an entirely different world. I'd think about

Hadfield's manganese steel, or Stellite overlays, or AMPCO metal wear

strips. Or maybe even something soft, like rubber.

* Bottom line. Is lubrication possible? How will the shape of the

parts affect the ability to induction harden? Are there issues regarding

forging/machining/ welding that may preclude a medium carbon steel?

You've raised one of those classic cases where the best solution isn't

easily determined. I feel that the best solution in real world applications

may well be determined by factors other that which method of surface

hardening provides the better wear resistance. If you need more info,

contact me at (513) 529-2647, or E-Mail at bardesbp@muohio.edu

Hope this helps.

Bruce Bardes