stainless steel finishing

[brents]

Hello all,

I have some parts that are made from 17-4 ph stainless..these parts are heat treated to h900 condition..

after heat treat, the parts are discolored..

I am needing to bring the "shiny" color back into the part because the customer likes the look..

I do not have time to hand polish these...

I was told that an "ultrasonic cleaner" would NOT work..

I need to find a way to mass finish these parts without adding any labor...

any ideas??

thanks,
brent

 

[EdStainless]

could you do it in a vibratory unit? Maybe with some mild abrasive. You should follow with a passivation to prevent rust stains.

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Plymouth Tube

 

[dgallup]

If they are small you can tumble them like EdStainless said, if they are big you are going to have to do some form of grit blasting. The finish you get will depend on the media you use but it will be more of a matte finish than a shiny polished finish. If you do this again, proper atmosphere control in the heat treat furnace can prevent the oxidation but it may take you awhile to find a heat treater who can do it reliably.

 

[NickE]

Vac-Met can give you H900 with a shiny surface, they use a H2 atmosphere, that prevents the heat tint film.

Always clean and handle parts prior to heat treat with gloves, the oil on your skin will leave horribly hard to remove discoloration on the parts.

If you do a tumbling process you will need to make sure you use clean media and clean process water. I've processed 17-7CH900 parts Aged in air, (Oxide surface), using vibratory methods, depending on media and type of machine you can usually get the film off w/in 4hrs. If you want a highly polished surface you will need to get the right media, and process water. I ran some part for 90+hrs once, they looked like jewlery....


Nick
I love materials science!

 

[brents]

thanks everyone, I sure appreciate the input..

I understand now about trying to PREVENT the discoloration..I will request that next time..

But for now, I have a lot of parts allready done and discolored...

I am sending some parts to different manufacturers of equipment so they can help me come up with a solution..

this way I can "try before I buy"...

thanks