"oil treatment" of metals 1

[toolingguy]

Our since departed plant manager has previously perscribed a dubious "oil treatment" of many stainless steel components in an assembly of a certain product we make. No one seems to know if such a treatment actually works.
I have taken on the task of flow charting the mfg. process for this assembly and weeding out the redundency and bs.
The parts subjected to this process are 301,302,303,304, and 17-7ph SST and are tossed in what appears to be a tamale pot containing a blend of Tri-Flow and WD-40 and placed in an oven for a period of 2hrs @250 deg. Thusly treated the parts are supposed to "slide easier". I have not found any difference in product life or performance.
Any thoughts?

 

[tripleZ]

Is this wrought SS? In powdered metal pressing (SS, iron, etc.) we'll control the porosity on some parts so that we have an interconnected porosity matrix. These parts can then be placed under vacuum/heat in a bath of oil and the oil will flow into the pores through capillary action. Once cooled, there will be a supply of oil within the parts which can be made to seep out under heated conditions. Google "self-lubricating bearings" if you're looking for more specifics on how the whole deal works.

As to baking it onto SS, my best guess would be that one would want to dip the part in oil, then air bake it. You should have a resulting layer of carbon deposited on the surface. This "might" give you some added lubricity, at least for a few slides until the coating flakes off. After that, your guess is as good as mine.

 

[toolingguy]

Yes tripleZ, actually these are stamped parts. Sintered pieces I can understand, but stamped??. I think the PM was feeding the chiefs a line of crap. At our place we do Class A medical/cleanroom work on one side and on the other side we make fishing reels. Go figure. The reel side of the company needs help quick and these components form the drivetrain of the reels. I've been asked to help out and streamline things and I feel that this "oil treatment" has gotta go. But I don't know everything, and wanted to verify this questionable process with the forum.

Thank you for your reply.

 

[BilletGuy]

I don't know about the baking on of WD-40, but there are readily available Dry Film Lubricants such as Dicronite that are used in many aerospace applications. A couple of calls to some of your local plating houses might get some explainations you need.

 

[tripleZ]

Balzers sells a turnkey solution for PVD coatings. Hardlube is one that comes to mind. The cost of the unit won't be cheap, but I guess it all depends on how many of these reel drivetrains you're making and whether or not the coating will offer you a sell-able benefit. My secondary machining dept. uses that and a few others on cutting tools, all of which help under higher levels of heat and stress.

If you're willing to drop around $250, you should be able to send them a fair number of samples for test coating (if you're interested in pursuing that route), then run a pilot test of coated vs. non-coated drivetrains.

I'm not going to try and sell you on a P/M solution, but depending on the shape/complexity of the component, you might find a cost reduction in that method over traditional machining methods you might be doing in house. Traditional SS P/M likely won't have the corrosion resistance you're looking for, but Ultimet 16 fully dense material might do the trick. Depends on what your salt spray requirements are.

 

[kenvlach]

toolingguy,
The phrase "a line of crap" is about right. 'Fu__ing stupid' is the technical term. Illegal, too, in California.
Is the Tri-Flow the kind with a bit 5-6%) of Teflon? If so, the WD-40 is probably preventing it from adhering to your parts. And, you're evaporating a lot of oils and organic solvents, which contaminates surfaces & plating solutions, creating painting & plating problems, plus gets into peoples' lungs (OSHA). Read the MSDS's. I've also had an unpleasant experience with an oven previously used for baking varnish at 250^oF; the outer shell was full of condensate that stunk when taking the oven to high temperature.

Both Tri-Flow and WD-40 are very high in VOC's (volatile organic solvents) aka ROC's, so your company is in violation of your AIR POLLUTION CONTROL DISTRICT's VOC limits given within the 'Surface Coating of Metal Parts and Products' rule (unless the oven has an effective, permitted incinerator for VOC's). Find your APCD here

http://www.arb.ca.gov/app/dislookup/dislookup.php

If your APCD doesn't haveon-line regulations, see the South Coast's:

http://www.arb.ca.gov/drdb/sc/curhtml/r1107.pdf

(the rest of CA usually copies their regs, and then eventually the US EPA).

For dip & bake dry film lubricants, there are aqueous suspensions of Teflon particles plus a lower melting plastic (binder). Most need baking at 400^oF or higher depending on binder, and wetting can be a problem with polished SS surfaces
But easier to use an aerosol can* of dry film lubricant (there is also a 'marine lubricant'), see pages 2017-2019 at

http://www.mcmaster.com/

*Aerosol cans have only recently became regulated by the SCAQMD, and are still exempt in many APCDs.

 

[toolingguy]

Thanks for all the replies!

BilletGuy: Yes I like the idea of dry film lubricants and have thought of Moly Coat. I would have to set-up a salt spray test and evaluate. I rather not use aerosols though. I like you idea and will investigate Dicronite.

TripleZ: Our company is swirling the going out of business drain and spending money to make money isn't an option for these guys. Coatings are a logical choice and in fact on the medical side I have been running "dry" tooling in our clean-room molding apps. with coatings from an east coast firm called Vergasson Technologies as the only friction barriers used in the tools. Great results! most sucessful!
Actually we looked into the PM solution and sent out RFQ's but were told by all that our quanities were too low and our part geometries were not difficult enough to realise an advantage over our current methods.
Our plastics engineer said he could rig one of our presses to mold green PM parts but once he found out that we have been in the red for over 10 years and that there was no r&d money the idea just died. I would have liked to see this happen.

kenvlach:
You're right on all counts and it's an unfourtunate set of circumstances for everyone involved. I have spoken with upper mgmnt. about your very concerns and they were "shocked" to realise something like this was going on. I am just a medium cog in sinking ship and would very like to see the company go green; solar, more recycling, etc... but these people are "old school" and getting them to open up their minds is very difficult. I will print out the reg's you have suppplied and show them to the CEO and put more heat on the situation.
As a side note, our mfg. neighbor is a plating shop and their fumes have destroyed our $150,000.00 chiller system on our roof, turned most of it into a lump of non-functional brown dust actually. Scuttlebutt is that the owner's (of the plating shop) son knows the local OSHA inspector and as a result our previous attempts at litigation have vaporised.

Once again you guys have been very helpful!

 

[rorschach]

If, once the orbital radius of your shop around the drain gets larger, you might look at xylan as a coating possibility, they can be dip/spray coated and baked. and the resulting surface is very corrosion resistant and self-lubricating (PTFE is part of the resin)

you might be able to use CS instead of SS for some parts in that manner.

 

[TVP]

FYI, Xylan is a coating from Whitford, should you choose to google it.

 

[toolingguy]

Thanks for all your replies, they have been most helpful!

The place I work for will not spend any kind of money at all so the only solution is a reduction of operations, movement, and reducing part count. I don't work for a normal company here, sorry. and we can't afford our shop towel service anymore and most employees are on work share. While I would like to see some investment in different coating methods, I have to generate cost savings by a subtractive process as there is no willingness to spend what little capital we have left.

rorschach: Thanks for the advice. I don't think that we can go with CS because our dies are clearenced for SST and are expensive "legacy" tools many years old. Also our assemblers will destroy (scratch) any baked-on coating of substance. As the fishing reels are deep sea reels, corrosion resistance is key.

 

[JohnNabors]

Xylan is great stuff. We use the 1331 grade on top of the 1391 primer for cast iron jet pump wetted parts in seawater applications and the corrosion resistance and surface lubricity is excellent. Just one thing to watch for- if you are going to have sliding contact use a Xylan grade that is based on Ryton as opposed to the Teflon based grades. With the Teflon, if you ever want to reapply it you have to get all of the existing coating off. With the Rytan you can "touch up".

 

[plasgears]

We had a highly stressed PM gear that benefited from oil quench after sintering. We theorized that the residual oil acted as a lube during initial run-in. There was a remarkable improvement in fatigue life.