What other steel has more ductile then S2 Steel

[petersi]

I made some axles (something like the attachment)using #45 mid carbon steel and S2 Steel for testing. The #45 steel is wearing way too fast and the S2 steel is better but still not good enough. I am looking for some advises on what other steel has more ductile and longer wearing then S2 Steel while the hardness can be the same or better? Also what treatment should be done? Thanks a lot. Oh, and of course the cheaper the better

 

[TVP]

Can you please provide some additional details:

What heat treatments did you use for the #45/C45/1045 and S2 tool steel?

What is causing the part to wear? Dirt, oxide particles, or other contamination from the environment? High contact stress with a bearing, spring, or other mechanical component? Something else?

Are there any impact loads or other dynamic forces? I am assuming that this is needed because you mention needing a steel with good ductility.

Is corrosion resistance necessary?

Some general things to consider:

1. You can achieve good ductility and wear resistance by case carburizing a low alloy steel such as 20MnCr5/5120. The core has hardness ~ 25-35 HRC and the case (~ 0.2 to 0.8 mm) has hardness 58-62+ HRC.

2. Nitriding (gas, plasma, salt bath) can provide very hard, wear resistant layers on plain carbon or alloy steels. They can be brittle, so dynamic/impact loads must be handled carefully.

3. Ni and Cr can be electroplated onto hardened steels for improved wear resistance. PVD coatings like TiN, TiAlN, etc. also improve wear resistance.