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View Full Version : Bearing steels as weld filler...?



Doc Nickel
11-03-2007, 05:15 AM
Yeah, I'll bet this is a new one. :D

Not too long ago, I discovered I could use simple music wire as TIG filler rod, to produce a sort of "hardfacing" weld. I used this mainly to resurface worn or damaged sears in various mechanical paintball guns.

It worked in that the small weld bead- almost just a tack weld- cooled quickly, almost as quickly as if it'd been water-quenched. It's much the same way that conventional hardfacing rod works.

Thinking about this, I modified the idea even further, and recently experimented with using old needle bearing rollers as filler rod- again, making short beads and quenching with a wet rag.

It seems to work, producing welds that are too hard to cut with a new file, but I started to wonder- what's in a bearing roller, alloy wise, and how is that alloy affected by being melted and requenched?

The use for the "hardfacing" is clearly not as critical as an actual roller bearing, so really, as long as I get a hard face, I'm set. But again, out of curiosity, anyone know how those metals might be affected, for better or for worse, by this sort of use? TIG, if it matters.

Doc.

Norman Atkinson
11-03-2007, 05:33 AM
I think there is a cross linkage with silver soldering HSS steels from CCWKen.

Music wire is really only a decent very ordinary carbon steel which was tempered.Tig-ing it is simply putting on ordinary steel but perhaps removing part of the carbon which was in it. The only reliable way to ensure glassy hardness is to use a case hardening powder- to add carbon. You may be doing this already but without knowing. One of my mates- long gone- used to use 'silver steel' which you call drill rod and dip it in case hardening compound to make his watch and clock making tools. So you were doing something similar to him. You could have been adding carbon from the shielding gas!

Regarding ball races and rollers, I fancy that you are doing nothing more than hard facing with decent quality steels capable of being hardened. You were obviously quenching with water to bring up the diamond hard state prior to tempering- or as we called it 'letting down'

With tongue in cheek, you and CCWKen were adding 'hard spots' to be found in poor quality steels which were not properly sorted and then smelted.

Most interesting. My father made his own steels and would have loved this discussion.

Norman

tryp
11-03-2007, 05:36 AM
Most bearing rollers and races are 52100 steel, its a high chrome high carbon steel, the downside of using them as hardfacing filler could be cracking as you quench and brittleness of the welds.

lazlo
11-03-2007, 09:30 AM
Yeah, I'll bet this is a new one. :D

Not too long ago, I discovered I could use simple music wire as TIG filler rod, to produce a sort of "hardfacing" weld.

You can use damn near anything for TIG filler rod, as long as it's clean: stick electrodes (with the flux knocked off), Romex copper wire for TIG'ing copper plate or bronze, even wire coat hangers, for mild steel.

Like Tryp said, bearing races are made from high carbon steel, and you may have issues with it cracking from the high heat and quick cooling.
You can probably avoid a lot of those issues if you pre-heat the parent metal, and slow the cooling after welding.

Benesesso
11-03-2007, 11:51 AM
>"You were obviously quenching with water to bring up the diamond hard state prior to tempering- or as we called it 'letting down'<

Interesting choice of words! In fact, diamond has the same basic atomic arrangement of its atoms as does the hard phase of steels, the well-known martensite. The arrangement is a distorted, rhombic shaped body-centered tetragonal (BCT), whereas soft steels (pearlite) is body-centered cubic (BCC), at least below ~1400 deg. F.

Norman Atkinson
11-03-2007, 12:24 PM
Benesso,
I am grateful for your comments about my choice of English.
It goes back to the family who came from the days of George Stephenson and also to a place called Shotley Bridge where swords were made by the cementation of carbon into the iron on the anvil. Something similar to the old Japanese craftsmen who still practise their skills today. Sadly, the German refugee craftsmen and the subsequent Consett Iron Company are gone.

I tried to keep to terms which would be of general interest and - after all- diamonds are made from carbon- but so are pencils. the other side of my families mined where graphite is still produced and pencils made.

If I had prattled on about Beehive ovens and such, it would have 'All our yesterdays'

Fascinating stuff- I was tempted to go into Wagnerian and Arthurian Mythology. I did resist. People would really have crossed swords.

Cheers and Thank You.

Norman