Jump to content

Stainless and high carbon san mai


owen bush
 Share

Recommended Posts

I would like to make some stainless steel san mai kitchen knives and was wondering if welding stainless steel was possable with a normal gas forge set up .

I was thinking of TIG seam welding the 3 pieces together before heating in forge maby leaving a small hole for the air to escape and then welding in a slightly reducing atmosphere .?

 

I know stainless is poo poo'd here however I believe it can be a beautifull material and have used It a lot for smithing work .

 

I was thinking of using .75% carbon core and 316 austenitic s-steel outers any help or clues would be great. I would intend to leave the forged finish on the stainless and then sand blast and polish it.

 

Personaly I love a good old carbon blade but the genteel British cook would not be so fond of getting his drying up cloths rusty.

forging soul in to steel

 

owenbush.co.uk

Link to comment
Share on other sites

ok, i know bog all about this, but i was wondering why you'd use austenitic ss? with a hc core, id be inclined to use a low carbon stainless to have the structural advantages of san mai and keep the stainless exterior. i know that some swedish blades are made this way, but the welding seems to be done by rolling at a very high heat. i guess you'd have to us a fairly reducing atmosphere with stainless, as i know from heat-treating 12-C-27 in a forge, any oxygen f$%^&'s up the steel, and the welding heats might be a bugger without running your forge rich.

Jake Cleland - Skye Knives

www.knifemaker.co.uk

"We can't solve problems by using the same kind of thinking we used when we created them."

"Everything should be made as simple as possible, but not simpler."

"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."

 

Albert Einstein

Link to comment
Share on other sites

I'm not realy fussed what to use as an outer .

 

I've never heard of the grade you mentioned .Ive got some 440c but wanted to use materials that I know and have already got .

I have 316 and 304 and for a kitchen knife I recon they would be fine .austenitic ss is tough and stainless ,more so than martensitic .

also I'm sure I saw an american maker making japenese kitchen knives with soft s-steel outer ,also a lot of scandies have mild steel outer and are exelent .

I would also be worried about the heat treating of two materials that have such diferent ht .

 

Anyhow all this is imaterial if I cant weld em ?????

forging soul in to steel

 

owenbush.co.uk

Link to comment
Share on other sites

I believe that you need a more aggressive flux when working with the stainless. I've heard of smiths adding fluorospar to their regular flux. Good ventilation is necessary as the fumes from the flux can do a number on your lungs. I have not ever tried, just what I've heard or read.

Edited by B. Norris

“All work is empty save when there is love, for work is love made visible.” Kahlil Gibran

"It is easier to fight for one's principles than to live up to them." - Alfred Adler

Link to comment
Share on other sites

I believe that you need a more aggressive flux when working with the stainless. I've heard of smiths adding fluorospar to their regular flux. Good ventilation is necessary as the fumes from the flux can do a number on your lungs. I have not ever tried, just what I've heard or read.

 

Well I had a go with a tig welded sandwich and It certainly didnt want to stick so I'm gonna need some ideas!!

forging soul in to steel

 

owenbush.co.uk

Link to comment
Share on other sites

Hi Owen

 

i've never done it... but if you do some patent searches .... there are patents on it for knives

 

check this out

http://patft.uspto.gov/netacgi/nph-Parser?...inless+knife%22

 

makes sure you have a tiff viewer .... like alterna tiff viewer... and click on the images part......and you can see the drawings on how they arrange the billet...

 

Look through all the reference links.......theres piles of stuff there.......

 

hope that helps......i'll keep looking

 

Greg

 

check the world patent site aswell

 

l

Edited by Greg Thomas Obach
Link to comment
Share on other sites

I think part of the problem is that in atmosphere the stainless form oxides which prevent the surface from sticking. Have you tried on a small scale first to put your small pieces of sanmai together and wrap it with heat treat foil with apiece of craft paper inside to burn off the oxygen. Bring it to heat and then weld together with out removing the foil until you are sure that it has stuck. Do this on small pieces first as a trial. Another possibility is use the can method . Make your a box but would have more grinding to remove it after the weld.

Link to comment
Share on other sites

Ariel Salvala(spelling) or one of the other Brazilian bladesmiths did a tutorial on this.He did it in a can.It was posted on TKN or Blade forums.

N'T McAhron Sqwaukin Vulture Verrinder

"to create is to make art"

TREMBLING EARTH KNIFE WORKS (website coming soon)

Link to comment
Share on other sites

Hey Owen,

Here is Ariel Salaverria home page I thought I remember he had a tutorial on it but could not find it. I would send him an email I am sure he can help you. http://www.aescustomknives.com.ar[/url]

Edited by Mike Turner

Mike Turner

 

 

http://www.turnerknives.com

Link to comment
Share on other sites

The best way to pull this off is to use a high carbon steel core, a layer of pure nickel on either side, 300 series stainless outer jacket. Weld the entire outsides all the way around(leave a 1/16" gap for gases to get out) with stainless rod or wire, use no flux and heat it up to welding temp and give it hell. the pure nickel acts as a medium between the hc steel and the stainless. Bad news is you can't draw it out very much due to the anvil affect the stainless has against the hc steel, so you have to start with material pretty close to finished size + or - 1/16". This is my way of doing it, I'm sure there are other ways but this works for me. Peter

Link to comment
Share on other sites

I welded 1095 shim stock and stainless heat treating foil, by tig welding all sides but I added a little diesel fuel and left a pin hole. Worked fine and looked good to.

 

You want NO flux in a closed weld.

 

Try coating your layers with diesel or WD-40 before welding them up.

 

Peter's plan sounds good, I can see where the nickel would want to stick to both steels better than they would to each other.

Don Hanson lll My Webpage

Link to comment
Share on other sites

Cold Steel uses san mai stainless blades alot.

Let not the swords of good and free men be reforged into plowshares, but may they rest in a place of honor; ready, well oiled and God willing unused. For if the price of peace becomes licking the boots of tyrants, then "To Arms!" I say, and may the fortunes of war smile upon patriots

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...