Hamon 1075 - unsuccessful

Blue Fin

Blue Fin

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Mar 30, 2017
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Hi knife makers & enthusiasts, my first posting in this section & apologies if this question is dumb or been asked before.

I finished my first gas forge and did my first three blades. I’m happy so far with the heat treat, looks positive although the differential hardening of the 1075 didn’t work.

I treated a W2 and a pair of 1075 blades - all same prep, clay application and quench. I heated the 1075 to just over 820 Celsius, the W2 soaked at 800-820. Quenched in Houghton’s fast oil (I believe very similar to Parks 50). Tempered. Sanded to 1200, then ferric etch & polished.

Results shown, I’m extremely pleased with the W2 but 1075 looks uniformly hard.

View media item 2556
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Why this result and what could I do to improve the 1075 ?

Thanks
 
IIRC Aldo has said his low manganese 1075 is actually AISI 1076 and that is why it produces nice hamon.
 
Where did the 1075 come from and when?

Did you use the same clay and technique/procedure on the 1075 as the W2? Dried the same amount of time, etc?
 
Thanks for replies gentleman.

The 1075 came from Gameco Australia, but I’m unsure of their supplier. One of the major US steel companies but I’m unsure which and when the bars came.

The clay technique was done in an identical way.

Would 1095 be a better choice, assuming I heat treat properly?
 
1095 should have .3-.5% manganese where 1075 is .4-.7%.

<.5% seems to be the demarcation point for whether a hamon is possible. The lower, the better.

I've gotten successful hamon from various heats of 1095 from various suppliers, but that doesn't necessarily guarantee it.
 
Jantz's 1075 is .6% Mn and Aldo's 1075 is .35% Mn, same as his 1095, and hypo-eutectic.
 
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One reason that there is such a variance in alloy content is that the source steel for the melt is recycled. It already has all sorts of alloying going into the melt. They just add te extra carbon to bring it up to the 1070 specs. Because of this, low Mn isn't common in most low cost steels. Look at a full assay of a melt and you will find small amounts of 6-10 elements not in the stated alloying (Fe, C, Mn, Si, S, P). Cr, W, V, Mo, Al, Cu, Ni, etc. are usually there.

I wish we could get one of the steel suppliers to make a virgin run of 1070 with less than .20% Mn and no other alloying beyond the small amount of Si that is inherent in a melt. I would buy 100 pounds of it. I need to ask Niagara/Crucible what a custom melt in an electric furnace would run. I asked my Crucible rep about 10 years ago and she said it would run about $5000 for a 100# batch, which I thought was crazy. I think she came up with that figure off the top of her head.
 
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I wish we could get a melt of Don’s w2!

OP, if you go through Aldo for your next order, I’d get a couple bars of w2 and one of 1075. They have different hamon activity so you can see what you like more.
 
Stacy E. Apelt - Bladesmith said:
One reason that there is such a variance in alloy content is that the source steel for the melt is recycled. It already has all sorts of alloying going into the melt. They just add te extra carbon to bring it up to the 1017 specs. Because of this, low Mn isn't common in most low cost steels. Look at a full assay of a melt and you will find small amounts of 6-10 elements not in the stated alloying (Fe, C, Mn, Si, S, P). Cr, W, V, Mo, Al, Cu, Ni, etc. are usually there.

I wish we could get one of the steel suppliers to make a virgin run of 1070 with less than .20% Mn and no other alloying beyond the small amount of Si that is inherent in a melt. I would buy 100 pounds of it. I need to ask Niagara/Crucible what a custom melt in an electric furnace would run. I asked my Crucible rep about 10 years ago and she said it would run about $5000 for a 100# batch, which I thought was crazy. I think she came up with that figure off the top of her head.
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Interestingly enough I'm trying to do exactly this, but from an ESR mini-mill instead of a PM mill.

I was going to ask for .7-.8 C and as clean as it can be, everything else <.1%. That should be a hypo or eutectoid that doesn't require a soak, will hit 65 RC and has the greatest hamon activity possible, right? While being water quench survivable because of the lack of nucleation in the grain boundaries.
 
kuraki said:
Interestingly enough I'm trying to do exactly this, but from an ESR mini-mill instead of a PM mill.

I was going to ask for .7-.8 C and as clean as it can be, everything else <.1%. That should be a hypo or eutectoid that doesn't require a soak, will hit 65 RC and has the greatest hamon activity possible, right? While being water quench survivable because of the lack of nucleation in the grain boundaries.
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Hitachi White #3.
 
Hitachi would be fine, but they won't ship it to the USA. We are stuck with the few sizes and varieties that Dictum and Workshop Heaven carry. It would be wonderful to get sheets of Hitachi white in #1 or #3. Ever wonder why none of the US suppliers carry it? ... They can't get it. Ask Aldo.
 
Stacy E. Apelt - Bladesmith said:
One reason that there is such a variance in alloy content is that the source steel for the melt is recycled. It already has all sorts of alloying going into the melt. They just add te extra carbon to bring it up to the 1017 specs. Because of this, low Mn isn't common in most low cost steels. Look at a full assay of a melt and you will find small amounts of 6-10 elements not in the stated alloying (Fe, C, Mn, Si, S, P). Cr, W, V, Mo, Al, Cu, Ni, etc. are usually there.

I wish we could get one of the steel suppliers to make a virgin run of 1070 with less than .20% Mn and no other alloying beyond the small amount of Si that is inherent in a melt. I would buy 100 pounds of it. I need to ask Niagara/Crucible what a custom melt in an electric furnace would run. I asked my Crucible rep about 10 years ago and she said it would run about $5000 for a 100# batch, which I thought was crazy. I think she came up with that figure off the top of her head.
Click to expand...
The lack of low Mn steels is not because the steels are "low cost." It's because the Mn is required for hardenability. Outside of developing a hamon there aren't very many reasons to have such low Mn. A minimum Mn content is added to take care of sulfur, usually in the 0.2-0.4% range, and beyond that is added for hardenability.

$5000 for 100 lbs is not crazy, that is approximately right. You can expect to spend between 4-5000 for 100 lbs. That does not include the cost of rolling and annealing, just the ingot. You can't compare the price of steel made by the tons for a variety of applications to a laboratory sized melting process making custom melts.
 
Hasnt aldo been talking about getting his own version of Hiatchi Blue from one of his german mills? He wanted to call it BLue Baron, Im still in favor of Aldo Blueno.

Is the 1075 Aldo stocks low manganese?
 
I see several dealers list 1075 and 1080 as interchangeable. As others have noted, Aldo’s is not really 1075, as the manganese is a lot lower.
 
Thanks Larrin,
Yes, I may not have said that clearly. I also had a typo in the steel type ( 1017 for 1070). What I was saying was that the steel manufacturers don't make it low Mn because it would be more expensive to make it that way, and like you said, it would not be needed in industry. I realize that our hamon making use is not worth consideration by a steel manufacturer.

When I made the inquiry, the $5000 figure seemed about $2000 too high. In todays market, $4000 is around what I though it would be. I am guessing, but the rolling would add another $10 per pound to the final cost. If the product is suitable for a superior hamon, it still could be cost effective since a pound at $50 could make a blade worth $400-$2000. Compared to the $200+ per pound you pay for raw tamahagane, $50 a pound doesn't seem so bad. I may look into this again. Do you have a recommendation for a company to do the smelt.
 
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