hardning mild steel is it possible

hi all for a project im doing at the mo i have a stainless steel rod with a notch cut into it and a mild steel block that flicks up and locks into the notch on the rod

now the problem is the stainless has worn a dip into the mild steel due to being harder so i need to harden the mild steel piece so that this does not happen iv had a quick search on the net but it said you cant harden mild steel i thort you could so if you can tell me you can and a method for doing it will be much apprecaited

thanks everyone

mike

You can case harden it by using a powder hardening product or there is pack hardening where you place the part in a sealed container with carbon containg material ie leather scrap) and heat it all up. Best to buy some powder from one of the ME suppliers. Unfortunetly you can no longer obtain Kasenit which was the best approach in the past.

Hi Michael,

in answer to your question, the internet was correct, MS cannot be hardened as it does not contain enough carbon for the process to be successful. As Kwil said though, you can case harden the item.

This involves increasing the carbon content in the 'skin' of the item, usually just a few thou' of an inch, this can then be hardened. It is used a lot to prevent wear insuch a case as yours. There are lots of recipes on the internet for a 'home brew' approach, these usually involve ingrediants which have a high carbon content such as charcoal, leather, and bones. These 'recipes' are to be found on gun making sites and forums especially in the USA. However I bought a quantity of a high carbon special powder from Ebay where a relatively small quantity was available for a few pounds.

The process involves heating the item to red heat and dipping it into the powder and holding it at red heat for a while then repeating the process. This produces the 'case' which can then be hardened by cooling rapidly from red heat in water - some folk use brine or even oil. If you go for the homebrew approach, the item is packed tightly with a carbon source in an airtight tin and heated to red heat and held there for a while, I have used a domestic wood fire for this. Attractve colours and patterns can be obtained with different 'ingredients.

Have fun,

best regards

Terry

Bone like whale bone was used in the past for diy hardening

1- kill a whale

2-crush the bone into a powder

3-put the steel into it and heat to a good temperature, like with charcoal, then allow to cool

Another one is oil plunging

Heat the steel to a straw/red heat and plunge into oil, which is rich in carbon

(I'd love to see how that one worked... from a safe distance)

If you search on "hardening" in the main forum you'll get a lot of good returns

It's quite an interesting subject

Sounds like case hardening will do the job you want, try a search for "Kasenit" should give you the info you need.

Sadly though you cant get that particular brand anymore but "Blackgates" sell an near identical product which works very well.

Easy process:

1/ Heat component to "Cherry Red"

2/ Dip/Roll component in Case Hardening powder (which sticks)

3/ Re-Heat component to same temp

4/ Quench in cold water swirling as you go.

Paul

Edited By _Paul_ on 16/06/2012 21:36:35

Step 1(b) You have to eat the whale, to get down to the bones.

wow thanks for all the very helpful info this surly is a great place to be on

atb mike

http://www.acentasteel.com/distribution/index.html

these people know everything about anything, I would thoroughly recommend that any one here buy their book if you want to know anything about stock steel.

andy.

Step 0.5, Have a whale handy

Not forgetting of course that whale oil was used in which to quench the hot steel.

We had a bucket full of it, in the hardening shop of the toolroom where I served my apprenticeship. Didn't smell all that nice.

It all sounds like witchcraft to me, because there are many other sources of carbon, without killing animals. I'm so pleased that whales are being protected at last.

That's enough of your blubbering, Sam!!!

Is casehardening by what ever method the best or easiest way forward?

It appears that the mild steel block is worn and needs (?) remaking, if so a better solution would be to up-rate the material used to a hardenable steel which would then be hard all through and not just on the surface.

John

My thought entirely. Why not make the part from gauge plate? It's tougher than mild steel, and is easy to harden if needed.

Regards,

Andrew

One part or the other is going to wear, its up to you which one is the easiest to replace, if the MS block is replaced with a harder block, you may end up replacing the stainless rod, the hard block may wear the notch. Ian S C