Does anyone have experience with the 420 ear stainless steel (it is remelted 420 for making molds)? I was given a good amount of this and was wondering if it is possible to forge properly (for knives and other tools). I was working with a small piece about 2" thick and 6" long and it is very tough to forge. It eventually ended up cracking. If anyone has any advice or procedures , it would be greatly appreciated.

 

 

knives?   you decide, what is carbon content? what does its hardening cycle consist of?  do you have the ability for that long of soak... Have you tried forging it? can you forge anything else?  you ask a very open ended question.

 

patient :      Doc thanks fro fixing me up,  can I play violin now?

Dr:    yes,

patient :  great because I never could before...

What Steve is trying to do with "grandmotherly kindness", (cf "Zen Flesh Zen Bones"), is to indicate that you should check FIRST then decide!

My ASM desk handbook, (1984 ed IIRC), didn't have 420 ear, but plain 420 has a minimum of 15 points carbon and the F grade had 30-40 points carbon; they both have quite a bit of chromium and no Nickel and a stout bit of Manganese.  I'd have to see the spec on your version but so far it looks like this grade is NOT a good knife grade.On forging it are you working it in the orange range and not hammering it cooler?

 

What was that quote from metallurgy class Patrick?---"Not everything needs to be made into a knife Patrick"

Edited July 9, 201511 yr by ThomasPowers

Thanks for the help... I can sort it out from here.

 One needs to pay close attention when working high alloy steels, they do not move like the simple steels most people are used to using.  and one does not always work like a different alloy either.   No sharp corners allowed, inside or outer corners.  And do not reduce cross sectional thickness too quick, let it take a few heats. 420 is not a bad place to learn but watch the reduction rates and forging as well as the post forging cooling rates.

Edited July 9, 201511 yr by Steve Sells

J

 

Edited July 9, 201511 yr by Bob S

Thanks for the advice Steve, I will try that.

T420 is forgable but quite stiff compared to carbon and low alloy steels. It is not generally used for blad cutting edges, but it can be used in the san mai technique in combination with a high carbon steel cutting edge to create a rather striking looking blade. I've seen this done with T416 and there is no reason T420 won't work.

ESR-Electro Slag Remelt: This is a method in which an ingot cast in the conventional manner is remelted. The ingot becomes and electrode, much like a giant version of a stick electrode for welding. The ingot is placed into a water cooled copper mold and melted slowing from one end to the other. this can take many hours depending on the size of the starting ingot. The melted metal passed through a layer of slag which helps catch any bits of non-metallic inclusion material that remained from the inital ingot casting process. The other big advantage of the remelting process is that it results in a final product with much less chemical segregation than an ingot cast in the convential manner. There is a similar process which is conducted under vaccum but with out the slag called Vacuum Arc Remelting. Similar benefits, but this process is particulary useful for removing dissoved gasses.