Newbie steel selection

[bwillhunt]

Hello
I have recently found this site and am very impressed. I have played around with different salvage steels (files, springs, etc.) but never felt like I got my efforts worth.

I was curious if yall could help me select one steel and the methods used to make a knife with it. I would like a steel I can make large and small knives with.

I have a small coal forge that works fairley well. It would be helpful if you could specify quenching solutions, tempertures, times etc.

Thank You,
Bill Green

[bg7m]

I think it is a good idea to start and stick with one type of steel while learning to forge blades. For large and small knives, I think 5160 would be a good steel.1/4" x 1" bar stock would be a good size to start with. I've made several knives from 5160, and it is one of my favorites, and it's easy to work with. I forge mine at about 1500-1600 degrees. Normalize 3 times, anneal 3 times, quench 3 times(in oil heated to about 160 degrees), and temper 3 times. A Google search for "forging 5160" steel will probably load you with information. Hope tis helps,

[Woody]

what is with this normalize 3 times quench 3 times, anneal 3 times, temper 3 times. If 3 is good why is 6 not better and 12 best?

Normalizing is a function of time AT temperature and then slow cooling not the number of times raised to temperature. According to JPH triple quenching has "some marginal effect on deep hardening steels like 52100 but otherwise is a good way to crack a blade." Tempering is once again a function of time at temperature not the number of times cycled thru the process.

[brucegodlesky]

I like a triple quench with 5160. I feel ya get a bit better blade.

[Woody]

do you have anything scientific other than your feelings to hang your hat on? What exactly are the metallurgical effects that are produced? Once again if 3 is good why is 6 not better and 12 better yet?

[bg7m]

what is with this normalize 3 times quench 3 times, anneal 3 times, temper 3 times. If 3 is good why is 6 not better and 12 best?

Normalizing is a function of time AT temperature and then slow cooling not the number of times raised to temperature. According to JPH triple quenching has "some marginal effect on deep hardening steels like 52100 but otherwise is a good way to crack a blade." Tempering is once again a function of time at temperature not the number of times cycled thru the process.

Perhaps you can try 6 times, 12 times and let us know. I only state what I know works for me. I have broken many small pieces of forged steel with different numbers of heat treatments and the "3" number produces the finest grain in the blades I forge.

[brucegodlesky]

IIRC, after 3 times, it becomes redundant with no appreciable gains. (for quenching)
I wish I could remember where I read that but CRS has arrived.
I heard Howard Clark say one time that 52100 could be thermal cycled to the point,( grain size reduced) that it would no longer harden properly.

[NateDJ]

I heard Howard Clark say one time that 52100 could be thermal cycled to the point,( grain size reduced) that it would no longer harden properly.

I have ask this question before but haven't seen an answer yet. After a piece of metal reaches this level of degradation is it possible to recover it by holding at high heat for a long time allowing the grain to regrow thus allowing for a restart on the heat treating cycle?

I am asking because I do not fully understand the processes involved and from what I read I gather many VERY different answers. Especially in the older heat treating manuals I read a lot of "If you ever get it over a dull red you will ruin the steel and it will never harden again" Then from places like this I read many different things which, when taken all together, makes my beard turn gray! :o

[Woody]

Once again I ask is there any scientific facts that you can hang your hat on other than "feelings and hearsay" Nothing I have been able to find anywhere advocates redundant normalizing, quenching or tempering. I think it is time we get the mytyology and alchemy out of bladesmithing.

[bwillhunt]

any other suggestions for steel types and methods?

Bill

[Mike Turner]

Bill 5160 is a good choice, the most important thing is it is it is forgiving to a new maker also it is inexpensive. I believe I read somewhere that 5160 has become the steel most makers prefer to use for their ABS Journeyman test.

[brucegodlesky]

Woody, can't tell you where to find that in printed matter. I don't read all that much anymore.
I suggest trying it yerself with whatever scientific methods you choose and seeing if you get any different results.
Not to come across as a smart xxx, I didn't see any reason for it to work at first. Tried it and likred the results.
I suppose you could DonFogg's forum and swordforum and get a clear explanation.

Edited October 8, 2008 by brucegodlesky

[Woody]

All I have been able to find concerning repeated cycles is:

The following was taken from:

Metallurgy of Steel for Bladesmiths & Others who Heat Treat and Forge Steel
John D. Verhoeven
Emeritus Professor
Iowa State University
March 2005

"When heat treating to form martensite, toughness is also enhanced by fine grained
austenite because it results in a finer lath or plate size in the martensite. Again the same
ideas apply. Rapid heating and repeated cycling produce smaller martensite
microstructures. Grange [8.3] has presented a study showing the beneficial effect of
small austenite grain size on the mechanical properties of 8640 steel. He achieved grain
sizes in the ultrafine range of ASTM No. 13 to 15 by a 4 cycle process where the steel
was austenitized in molten lead for around 10 s, cooled to room temperature, cold worked and then cycled again. A series of similar experiments was performed here on 3 steels to examine the effectiveness of thermal cycling alone, no cold working was employed. The steels were heated by immersion in a salt pot. Initially the steels were austenitized for 15 min. at 1650 oF and oil quenched in rapidly stirred oil. Then the steels were given 3 thermal cycles consisting of a 4 minute austenitization in 1450 oF salt and a quench in rapidly stirred oil. The grain sizes were measured with the same technique described by Grange [8.3] and the ASTM numbers before and after the 3 cycle treatment are given in Table 8.2. It is seen that ultrafine grain sizes were obtained. Figure 8.5 presents photomicrographs of the martensite structures found in the 1086 steel before and after the cycling. The composition of this steel is in the range where we expect the martensite to be a mixture of lath and plate morphologies, and in the uncycled coarser grained sample Fig. 8.5 (A), one can see dark plates in a matrix of the lath structure. However, in the finer grained austenite produced by thermal cycling, Fig. 7(, the martensite structure is clearly finer and the plates are not easily identified.

Table 8.2 ASTM grain size no. of austenite before
and after the 3 cycle treatment done here.
Steel ASTM Number
Initial After cycling

1045 9 14
1086 11 15
5150 8.5 14 "

in this case a higher number indicates a smaller grain structure

repeated quenching does refine the grain structure but it was done under very controlled conditions heating the metal in a salt bath and holding it at temperature for a specific time.

I can find no mention anywhere that repeated normalizing, annealing or tempering has any additional benefical effect.

[brucegodlesky]

Woody, I believe the redundancy,3x, is a result of the rather primitive HT methods we use. Most knifemakers aren't using a Paragon or salt pots. The 3x methods give a bit of assurance that the temper, grain reduction, normalization, stress relief , etc is achieved.
This is just my opinion and how I have to look at it to make sense. YMMV
Take the time to make up some simple bars, normalize, harden temper using different methods. Break them and examine under magnification to see if there is a difference.
For me, I think that 2 normalizing sequenses then 2 quenching sequences works as well as 3 n then 1 quench. bruce

[kbaknife]

Bruce, did you know that just following forging, and BEFORE the three thermal cycles/normalizing heats, Ed Fowler does three austenizing quenches? I did his Seminar a few years ago.
Right after forging, do three reducing heat full non-mag quenches in room temp oil with 5160/52100.
Then follow this with 3 just non-mag normalizing cycles.
This virtually eliminates all subsequent warping that may occur, as well as gives REALLY nice and even fine grain, proven by his photomicrographs.
Pretty much what Verhoeven is saying above.

[brucegodlesky]

Yesd, I had read that before Karl.
He's using a Paragon, isn't he?
Bein' a brain damaged Polak hillbilly, I have a hard time expressing in words what I see in my mind :-)

[kbaknife]

He uses his Paragon for spherodizing and tempering.
The post forging quenches are done with the forge as the heat source.

[otto]

O-1 makes great blades but is hard as xxxx to work ,1085 is better to work and heat treats easy. but I love 5160 :)

[nc_cooter]

Here"s a good read on the effects of multi quenching and /or normalizing from another forum. Pay particular attention to what Kevin Cashen has to say about it.

Effect of triple quench - BladeForums.com