damascus edge holding

[TimB]

Just curious, but it seems to me that a blade made out of two different carbon content steels would have "soft" spots in its edge, and depending on the pattern, could wind up with significant portions of the edge softer than the rest of it. Is this true, and what would be the experiences any have had on the use ability of the blade.


I have carried a carbon steel Schrade 5" belt folder for 30 years, and the blade now has little more steel than your average 3" pocket knife. I tend to shy away from SS blades like Buck. I sharpen them with a hand stone, and tend to preferr the harder sharpening steels that hold their edge well. That's my experience with knife steels, just wondering how Damascus would generally compare.

[Robert Mayo]

If the damascus is made from two steels that harden and have similar carbon content and heat treating it will harden at the same hardness as a mono steel knife of the same steel if properly heat treated.

Bob

[me miller]

And it also depends on layer count, how the surface is manipulated to get the pattern, and what hardeness the original edge is brought to. A twist pattern with high count will be different than a ladder with a lower count. You end up with more of a serration edge than a big lump of non hardenable material on the edge. Jerry Fisk at one time hardened his damascus to RC52 because he felt it gave it a better edge for chopping.

[pkrankow]

After about 4 or 5 folds the carbon content is equalized throughout the billet. There has been testing done to this result.
http://www.google.com/url?sa=t&source=web&ct=res&cd=2&url=http%3A%2F%2Fasmcommunity.asminternational.org%2Fvgn-ext-templating%2Fviews%2FASM%2FOpenDocument.jsp%3Fvcmid%3Df83e5bc60524f110VgnVCM100000621e010aRCRD&ei=SHqDSpSAAo24M_bRndUE&rct=j&q=carbon+diffusion+in+pattern+welded+steel&usg=AFQjCNFb4Q2O_GnipL6WOA84RzvNB7DcBg

http://www.google.com/url?sa=t&source=web&ct=res&cd=3&url=http%3A%2F%2Fwww.lehigh.edu%2Fsymposium%2F2009%2Frceas%2Fattach%2FNizolekPoster.pdf&ei=SHqDSpSAAo24M_bRndUE&rct=j&q=carbon+diffusion+in+pattern+welded+steel&usg=AFQjCNHYTRKSXxuGLZCr99oHQ9CwXmWm5w

Carbon is not the only thing that affects hardness though, so you can still have small hardness differences along the edge.

Phil