Less Aggresive Oxide Remover for Stainless Steel 2

[BMccarthy81]

We're having a problem with some diamond drawn stainless steel wire for medical instrument use. The straightening process of the wire scratches the surface, usually unpercieved by the human eye. The material itself is very hard and needs to have a hole drilled into it, therefor the ends are annealed so the material is soft enough to drill. The annealing process causing oxide to build up on the ends, and because its used in medical instruments it needs to have a uniform bright finish. The discoloration is corrected by immersing the ends in an oxide-remover called Ox-Out. The problem we are having is that the Ox-Out is etching the material where it was scraped by the straightening process, giving it a look of spiral tattoos. Due to budgeting problems we cannot add extra steps, such as polishing, to remove the spirals, or we can't change the current process that we have now. We are looking for a less aggresive Oxide remover that will clean off the ends, but not etch the scraps. Does anyone have any suggestions?

 

[MikeHalloran]

You couldn't just use softer tooling for straightenting the wire?



Mike Halloran
Pembroke Pines, FL, USA

 

[BMccarthy81]

The wire is straightened by the customer. We do not have any control on it.

 

[BMccarthy81]

also the material is 304 stainless and .033 inch diameter.

 

[MikeHalloran]

You wouldn't have to anneal the wire to drill it with a laser.



Mike Halloran
Pembroke Pines, FL, USA

 

[BMccarthy81]

We cannot change or add any steps in our process, the budget is tight, but we feel that the cleaner we are using, OxOut 536, is too aggresive for our material.

 

[ijzer]

You could anneal it under argon gas protection to avoid oxydation.

 

[BMccarthy81]

The annealing we are doing in house, its a simple furnace that can get up to 2000F, sadly we cannot put them in an inert gas atmosphere, it will add onto the cost. Again i'm looking for an oxide cleaner that will not leave an etch.

 

[moltenmetal]

Are you concerned that your cleaner is removing base metal as well as oxide scale? Do you know that base metal removal is occuring, or are you just speculating? Because if your desire is to simply do a poorer job of cleaning the oxides that are there, the answer to your question will be very different.

 

[Latexman]

"OxOut 536 is too aggresive for our material."

#1 - Reduce the immersion time.

#2 - Reduce the temperature of immersion.

#3 - Dilute the OxOut 536.

Good luck,
Latexman

 

[btrueblood]

Even with a "simple furnace", you can buy some 321 stainless steel foil, fold it into an envelope or bag, and plumb a length of stainless capillary tube into the bag. The tube should be thin enough to be able to pass thru the door seal. Apply pressure to the end of the capillary tube via gas regulator (you can calibrate the flow by timing the rate of bubble formation in a beaker of water). Keep the purge flow low enough, and no worries about blowing the door off.

If you want a true "bright anneal" use up to a 5% H2/95% Ar mix.