Making a laminate steel with ultra high carbon content?

[Diamond G Knives]

Hello Folks
I am brainstorming the idea of making a laminated chefs blade with the inner core being a very high carbon steel. I understand that powder steel can have carbon added by adding graphite to the mix. Could I take say 1084 powder steel, and a percentage of graphite and get the carbon content up to around the 2% carbon content? If so, what % of graphite? Does the graphite need to be suspended with a bonding agent in the mix?

I am wanting to have a mild steel outer core. Would I need a layer of nickle between the two to keep carbon migration to a minimum?

This will be a slicing and dicing knife, not a chopper, but Im sure I will need to temper to some degree.

Just wondering if anyone here would have any input.

Thanks in advance.

God Bless
Mike

 

[Stacy E. Apelt - Bladesmith]

I'm not sure why you would want to laminate it up that way,but the answer to your question is -NO.Without alloy elements you can't get that much carbon into solution in a knife steel.It wouldn't work the way you said ,either.Use 1095 for the core,if you have a reason to do this.D2 would be another choice.The HT will be a bit complex.Forget the nickel.Also,There is no hardness advantage to higher carbon content above 1%,anyway.You need to temper all HC steel.What you are describing is a Swedish laminated steel blade.

 

[Burt Foster]

You need to approach the entire project from the question "why?"

Why do you want a super high carbon blade? The blade won't get any harder than something like 1095, and it won't be any tougher. The law of diminishing returns applies here. For a slicing kitchen knife with a very thin edge, you can get away with a RC 61-63 if everything else is right. However, understand that with the most expensive Japanese kitchen knives with these types of edges, you will still chip them if you set them on the counter wrong. Everything's a trade-off so understand that going in.

Second, why do you want a laminated blade? If it's for looks, fine. If it's for function, there's really no need. A homogenous carbon steel can be differentially hardened or tempered to give you the hard edge, soft or tough back that you're after, and the lamination is redundant. Most Japanese kitchen knives are laminated with stainless outer layers for stain resistance, not toughness. If you use mild steel, then of course there's no extra stain resistance.

As to the nickel, yes it would prevent carbon migration, but again, that is largely a non-issue, since carbon will only appreciably leave the area in immediate contact with the mild steel, not all the way to the center of the layer, which will comprise the edge. Also, nickel will help the two steels bond if they are very dissimilar - like D2 and mild steel. You wouldn't want to use it in a damascus blade where the nickel will end up on the edge, but for a laminate it's fine.

That said, give it a shot. If you decide that your reason for all of the above is "Cuz!" then go fo it and tell us how it works. Kitchen knives are an area largely neglected by knifemakers, because there is traditionally less of a market for "collectible" kitchen knives. But, there is a great deal of need for high performance kitchen knives, as chefs are really the last professional knife users in this country and many others. I promise you that if every knifemaker devoted even %10 of his time to kitchen cutlery, our understanding of knife performance would improve dramatically, and all our knives would benefit.

 

[Jeff Clark]

The Japanese do this often. Frequently they use a sort of ornamental damascus or wrought iron outer layer and a Hitachi Blue Steel core. This allows you to get a very fine hard edge on blades made from soft or coarse outer materials.
http://www.bladeforums.com/forums/showthread.php?t=317754

I guess my question is why not use laminated blades? It allows you to get a tough blade with a hard edge without the obvious disadvantages of differential hardening (only being able to sharpen the blade partway to the spine before you run out of hard metal). Laminated blades are the best blades, the only reason to use anything else is cheapness or stubborn traditionalism.

The way that I would experiment with making a laminated blade would be to use a 1095 core and 1050 side layers. I would heat treat the blade as such as to get the 1095 to 63 RC. This should leave the outside layers softer and tougher. I don't actually see this as a huge advantage for most kitchen knives, but it might make an interesting hunting knife.