D2 and Rusting

Thanks everybody. Promise, I will try again if I can find some time and courage :grumpy:
. Now its time to making reed knives,..
Oh, that african black wood is sooo nice to polish. Blades are shining, bevel lines are crisp, this is the most satisfying work I've ever done.... :D :cool: :cool:
 
Note to all who use a magnet....The non-magnetic trick only works for standard HC steel like 1095 and maybe O-1.For stainless and high alloy steels you will need higher temperatures.It is a good way to learn what 1600 degrees looks like,but is no replacement for a controlled oven in HT.
 
Hey, thats a great info :) ...
I always treated D2 as a high carbon steel. What I did was, if it doesnt stick then rise the temperature a little then soak. Now you say I have to rise it more, and yes it is valuable info... Thanks,,,
 
I harden D2 at 1020°C (1870°F). At that temperature, it comes out of the furnace at a bright yellow color-if that helps.

You really ought to look for a used pottery kiln. One could be adapted pretty easily and you could get a lot of the guesswork out of treating high alloy steels.
 
I was thinking about using one for air hardening steels like D2, or A2 where speed of quench is not critical. The worst feature of most pottery kiln is that they are top loading. You could build a rack that could be picked up with a long handled hook to get several blades out at once. They could then be quenched in a large pan of oil. You can quench any air hardening steel in oil-in fact Uddeholm reccommends an interrupted oil quench for tool steels with simple geometries.
 
I looked into rebuilding it but it almost looked like I could come out about the same just buying a new one. Thanks for the respark of my interests :D
 
Mike Hull said:
Why not just grind a blade out of D2. It's done all the time, and it makes excellent blades. It doesn't really gain anything by forging anyway.:eek: :confused:

To me, it's like forging 440C, ATS34, etc. Sure, it can be done, but to what purpose. After all the time and trouble, you still have 440C, ATS34, etc., with no gains, and probably the worse for wear in the bargain, as the D2 above shows.
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Why wouldn't a stainless steel gain anything from forging? In my opinion, a stainless steel would gain more than a carbon steel. One thing people often talk about with the advantage of forging is reducing grain size, it's stainless steel that has the large carbides and grain, not carbon steel.
 
Larrin said:
Why wouldn't a stainless steel gain anything from forging? In my opinion, a stainless steel would gain more than a carbon steel. One thing people often talk about with the advantage of forging is reducing grain size, it's stainless steel that has the large carbides and grain, not carbon steel.
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SS that only has Cr carbides will have large carbide grain size. Sub micron sized Vanadium carbides pin the structure of the CrC along the boundaries, preventing large grain growth. Both D2 and the better grades of SS have significant amounts of V. If they are allowed to soak at Austenitizing temps, grain growth will be minimal. If the temp is too high, growth will take off in the Austenite. If the soak is too short the carbides will not properly dissolve/diffuse allowing the intiial carbides to be larger. This is why steel manufacturing companies call for 30-60 minute minimum soak times for tool and stainless steels.

If the soak times are not followed the steel has not been optimally heat treated.
 
Larrin,The myth of reducing grain size (and "edge packing") mechanically by forging is just that- a Myth.All changes to grain size done in forging would be erased in the hardening soak and quench.The advantage of forging is the ability to control material waste ,shaping,and stress.Stainless steel can only be worsened by the temperatures it is forged at.Reducing a round bar to a flat preform would be one thing,forging to shape would be wasted effort,and cause detriment to the steels quality.
 
bladsmth said:
Larrin,The myth of reducing grain size (and "edge packing") mechanically by forging is just that- a Myth.All changes to grain size done in forging would be erased in the hardening soak and quench.The advantage of forging is the ability to control material waste ,shaping,and stress.Stainless steel can only be worsened by the temperatures it is forged at.Reducing a round bar to a flat preform would be one thing,forging to shape would be wasted effort,and cause detriment to the steels quality.
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"edge packing"
this one had been done a few times.. :)
http://www.bladeforums.com/forums/showthread.php?s=&threadid=288176&perpage=20&pagenumber=1
 
I never said edge packing, I said grain refinement. While not much refining of the grain may be done in just a small blade, with how much reduction is done in damascus, I think the grain will be refined, which is not the same as all of the steel particles being compacted together.
 
Ok,
here is my opinion about this subject,

I forge because I am lazy, I want a bevel on the knife or thickness of the blade acquired in minutes. I tried to stock remove one of these "easy to make" reed knives and it took all my night :barf: . I can shape and profile it in max 30 mins at the forge not in 5 hours by the grinder. You add only finish grinding, though I do it after HT, this eleminates carying the stress of the grinding to HT. Also I anneal the blades as soon as it is forged, so the grain dislocations is minimized as far as I know. But what do I know, I am only a beginner, mostly messing the steel up during forging or HT :D .

By the way, what is the aus-forging that I do. Is it that mythical "edge packing" or something else? I do it the way I learned from "Complete Bladesmith" book. I broke one or two blades this way :D. I always boast about the way I aus-forge, now I figure its better to boast about something that I know :confused: :D .
 
Grain forms as the metal cools from a free atomic state (above critical) to a matrix state.The rate of cooling in steel determines the forms of matrix that the steel goes through AND the size of the final grain particles.In folding damascus you are creating a "grain" like that of wood,not a crystalline lattice as in "grain size".The layering of the steel,and the reduction of the layers to very thin cross section,gives the damascus its flexibility and toughness. - Stacy
 
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