Surface Finish For Stamped Parts

[ajensen]

Hi All,

Is it possible to achieve a 32 microinch surface finish on a stamped piece of thin (~.060") hardened steel (440C...~Rockwell 60)? Could I get even better? 16 microinches? Would post processing be necessary?

Thanks,

Aleck

 

[btrueblood]

Not sure how you will stamp (deform plasticly) a piece of 440C steel, it will likely fracture before you get much deformation.

Can you stamp it in an annealed condition and then heat treat? Yes. Can you stamp it and get good surface finish - yes, I've seen very nice, 32 rms finish or better on stamped stainless parts (302, 304, though, not 440), mostly it will depend on depth of forming, bend radius, finish of the tool. I.e. "it depends". To get really nice finish (8 rms or therabouts), though, we have resorted to polishing.

Can you keep a 32 finish across a heat treat cycle? Tentatively yes, but I think you will need good atmosphere control to prevent oxide build up. 440C I think requires a quench, which can be difficult to do in controlled atmosphere, but I have heard of it being done.

 

[DYV1973]

Depending on where you want your surface improved, and how large your products are, you can consider using a vibratory bowl or tumbler.

DYV