Annealing thick stainlesswire - can it be esily done?

[Eric The Viking]

I think my wife dropped something like a spoon into the Kenwood Chef's mixing bowl whilst it was running. The whisk's wire beaters are badly bent - almost all of them. I'm fairly certain I can straighten them again (it does dismantle), but I'm worried about the wire work-hardening.

Can anyone suggest how to anneal them? I don't know which grade of stainless they are though, and they're about 1/16" in thickness (dunno the wire gauge).

Thanks,

E.

PS: haven't looked for spares yet on t'internet. If they're cheap enough I won't bother, obviously.

 

[Cheshirechappie]

I think I'd be tempted to firstly, check whether spares can be obtained, and if they can, just bend the ones you've got straight. If any break, either clean off the broken ends and live with one less wire, or resort to buying the spares.

I don't know much about the heat-treatment of stainless, except that it doesn't behave as well as carbon steels. You end up with all sorts of wierd problems like chromium carbide precipitation, causing localised chromium depletion and consequent increased likelihood of corrosion. If you did succeed in softening the wires, how would you re-harden afterwards to ensure they were strong enough for normal service?

Edit to add - After a bit of googling, the general concensus seems to be anneal by heating to bright orange (close to 1000C), then quench in water to avoid chromium carbide precipitation. Hardening by heat treatment of austenitic stainless doesn't work, but it can be work-hardened. Martensitic grades can be hardened by heat treatment, as outlined below:

http://www.azom.com/article.aspx?ArticleID=1141

 

[Eric The Viking]

Thanks CC,

It turned out to be 'entertaining'.

I used the least worst bent one as a model, and worked the others as near to it as possible. As I suspected the places where the bends should be were work-hardened a bit and thus it wasn't easy, but I got away with it.

There are five wires, but the bloomin' things are 'knitted'. I hadn't realised, and put it together once by just putting each successive wire over the others - wouldn't stay in shape! Enter #2 daughter - handy when she's so inclined. Extra, dextrous fingers (and a knitter's experience) made all the difference. Over-under is the way to do it, it seems.

Now bent straight, cleaned and polished and back in the cupboard. Apparently someone managed to turn on the mixer with a dough hook attached and the whisk still in the bowl! Anyway, it gets the seal of approval, and £20 saved is £20 saved.

Cheers,

E.

PS: Googling brought up http://www.4kenwood.co.uk/chef-food-mixers/catalogue.pl?path=590704:622774, who have lots of spares, in case anyone else needs them. Not inexpensive (eye-wateringly pricey for some items like rubber seals!), but available, which is the point really.

PPS: Ours is 30 years old next year, and the bolt in the centre, frustratingly, is imperial. Had it been M6, she'd have had a nice, stainless, Allen-headed machine screw in the middle. Sigh.

 

[dickm]

Possibly a good job you didn't try to anneal the wire - the thought of mixing food with any chromium ions that were so liberated isn't a particularly nice one.
If I remember, will have a look in our various boxes of Kenwood spares tomorrow. Have a feeling there is a whisk somewhere among them if it's any use to you.

 

[Eric The Viking]

You're very kind, but it looks OK for now.

I'll have to see if it gets DCA (Domestic Controller's Approval), next time there's baking to do.

It's a tough standard to meet, but mentioning the price of a new spare seems to help the case...

Cheers,

E.

 

[Dalboy]

Sound like job done does that mean £20 to spend in the workshop