Damascus issue that is above my knowledge.

[Dan727]

Hi everyone, I tried to search for my issue but haven’t had any luck.
I have been making blades for around 6 years now and I love making Damascus, I make 95% of my blades with 1084 & 15N20. I have a physical disability so I don’t make blades as fast as others, I take my time so things like this don’t happen….. that normally works lol
My issue is when I etch this dagger it looks to have glitter or sparkles on the surface. I broke a small scrap (end cut) after heat treatment and the grains looks perfect so it’s not large grain in the center. I will add pics below with the hope that someone else has had this issue and can inform me what went wrong. I don’t want to repeat it lol
I use a heat treat oven and so all my cycles are as recommended from my steel suppliers website. Thermal cycles & quench all the same as every other blade I make. I made a blade a few days before the dagger and it was perfect. I thought maybe I just screwed up the heat treat so I went threw all the steps again to make sure it was by the book but it came out looking the same.
The only thing I did different was I ran out of 1084 and needed a few more pieces wile forging to 400 layers so I used 1075 from my same metal supplier. I don’t use other metals so nothing was mixed up on my end and the 1075 was a full fresh bar with the name & size marked on it. I also thought maybe I contaminated my ferric chloride so I drove to Radio Shack & picked up a few new bottles but with no change. I use a 3:1 ratio with distilled water. I do use canola oil heated to 140 and I change it out after about 10 blades so its still good.
Thanks in advance for any advice & happy holidays to all.

This is the blade that was made a few days before and the only difference is the dagger has 1075 added before the last forge weld.

 

[Stacy E. Apelt - Bladesmith]

I get that sometimes. It is large grain in the simple carbon layers. With no V or W and fairly low Mn, the grain grows easily in the many high heat cycles.
It can be eliminated by doing grain reduction cycling of the billet after basic forgoing to shape.

 

[Dan727]

I get that sometimes. It is large grain in the simple carbon layers. With no V or W and fairly low Mn, the grain grows easily in the many high heat cycles.
It can be eliminated by doing grain reduction cycling of the billet after basic forgoing to shape.

I appreciate the help Stacy, if you don’t mind can you let me know what temps work best for you when your using 10xx (other than 1095)
I currently do

1st cycle) 1,650°F 15 min)

(2nd cycle) 1,500°F 15 min)

(3rd cycle) 1,350°F 15min)

Then 1460 F for 15 min before quench.
Thank you again for you time & input, it’s greatly appreciated.

 

[Stacy E. Apelt - Bladesmith]

Those numbers should work with simple 10XX mono-steels worked in the forging temps (1800- 2100°F). If you have been working a damascus billet repeatedly in the welding temps (2200-2300°F) then you might want to try 1700°F for 15 minutes as the first cycle. Also, try quenching from the 1500°F and 1350°F soaks, too.

another thought is that this coarse pattern is caused by the surface of the low carbon low allow 10XX steel mushing apart slightly in the heavy hammering and high temps. These separated islands will not rejoin fully as you work the billet down at lower temps, leaving that aggregate look. Hopefully Larrin will chime in with his thoughts.
Some of the full time damascus guys may offer a solution, too.



Here is an older post of mine on forge welding for those interested in the metallurgy of what is happening:
I'll add a little physics to the metallurgy here. The explanation below isn't meant to be an exact scientific discussion, but is intended to explain the transfer of energy involved in forging and welding.

A weld is when the two metal surfaces combine into a unified structure. It is basically like having the two melt together along the junction of their surfaces at an grain size level.
This requires enough heat to allow the grains to move and interlock with each other. Further refinement by forging down ( or rolling) increases the unified bond and makes the joint stronger.
Heat is energy, and heating an object is merely the absorption of energy. Bend a coat hanger and it gets hot because you are adding energy in the bend. Compress air rapidly and it gets hot because you added energy to the molecules/atoms. Hammer a bar of steel and you add energy to the grains as you force them together.

In forge welding by hand, it is all a factor of how efficiently you swing a hammer the weight of the hammer, the distance it falls, etc. - For practical purposed a 3 to 4 pound hand hammer is the limit you can effectively swing, and an 8 to 10 pound sledge is all a striker can easily swing.
A power hammer delivers multiple blows with a bigger hammer. They range from 25 pounds to hundreds of pounds in hammer weight. The normal range for knifemakers is 33 to 100 pounds.
A press delivers many tons of pressure, witch is roughly equivalent to a very large hammer. Forging presses usually deliver a fairly quick force of around 40,000 pounds (20 tons). This is a lot of energy, but you only get a few presses at welding heat before the mass drops below the fusion point.
A rolling mill squeezes the metal from both sides and delivers a very intense addition of energy at the rollers. This is the most efficient way of reducing thickness or welding laminated ... but not practical for small shop knifemaking.

If a hammer was big enough, theoretically you could weld at room temp. In practicality, the steel has to be at least 1600°F to weld with a giant hammer or rolling mill.

The range where the atoms can move enough to fuse but not mush the billet apart is roughly 1600°F to 2300°F. For most hand forgers, the upper limit of 2200-2300F is the advised range, For those with a press or power hammer, 2100-2200°F is better. I would suspect that the big places with giant 500 pound hammers and 100 ton presses go down as low as 1800°F.

The sweet spot for welding is a temperature where the steel is still solid enough to survive the pressure of welding, but not so high that the grains slide apart or fully melt. The exact temperature is almost always judged by eye and learned by experience on your set of equipment. The bigger the hammer or press, the lower the temperature of the billet can be. As the hammer or press delivers energy to the billet, the temperature rises. You can see this when forging. As the steel drops to a duller red, strike the bar hard with a hammer. You will notice the color jumps up a good bit at the spot impacted … and quickly drops back to the lower heat color as the energy gets dissipated into the surrounding steel.

All forge welded billets should get grain refinement procedures to lower the grain size. You need to both refine the grain as well as release any internal stress from the welding and reducing procedures. Everyone has their own methods, but they should include reduced cycling temperatures ending in a quench, This is best done as soon as the billet is reduced to the thickness desired and/or the blade rough shaped by forging. These procedures need to be done prior to the hardening quench to assure a blade with internal integrity.

Summation:
Metallurgically, the forging range of most knife steels is between 1600F and 2100F. If steel is in this range the damage to the grain is minimal and correctable. For forging you have enough energy in the steel for the task of moving the grains around to re-shape the billet as needed. For welding you need more energy. Picking a place where the steel's structures are still unaffected but the added energy fuses the weld is what you are shooting for. Start at what you think is the bottom of the range. If you can master that range and get solid welds, your blades will benefit. If the welds aren't solid enough with your methods and equipment, then raise the temperature. The only practical gauge is your eye.
Once the layers are bonded, lower the heat by around 100 degrees to work and solidify the billet. Proper stress and grain reduction should follow the welding and reduction .

May 5, 2019
Stacy E.Apelt

 

[Dan727]

Those numbers should work with simple 10XX mono-steels worked in the forging temps (1800- 2100°F). If you have been working a damascus billet repeatedly in the welding temps (2200-2300°F) then you might want to try 1700°F for 15 minutes as the first cycle. Also, try quenching from the 1500°F and 1350°F soaks, too.

another thought is that this coarse pattern is caused by the surface of the low carbon low allow 10XX steel mushing apart slightly in the heavy hammering and high temps. These separated islands will not rejoin fully as you work the billet down at lower temps, leaving that aggregate look. Hopefully Larrin will chime in with his thoughts.
Some of the full time damascus guys may offer a solution, too.



Here is an older post of mine on forge welding for those interested in the metallurgy of what is happening:
I'll add a little physics to the metallurgy here. The explanation below isn't meant to be an exact scientific discussion, but is intended to explain the transfer of energy involved in forging and welding.

A weld is when the two metal surfaces combine into a unified structure. It is basically like having the two melt together along the junction of their surfaces at an grain size level.
This requires enough heat to allow the grains to move and interlock with each other. Further refinement by forging down ( or rolling) increases the unified bond and makes the joint stronger.
Heat is energy, and heating an object is merely the absorption of energy. Bend a coat hanger and it gets hot because you are adding energy in the bend. Compress air rapidly and it gets hot because you added energy to the molecules/atoms. Hammer a bar of steel and you add energy to the grains as you force them together.

In forge welding by hand, it is all a factor of how efficiently you swing a hammer the weight of the hammer, the distance it falls, etc. - For practical purposed a 3 to 4 pound hand hammer is the limit you can effectively swing, and an 8 to 10 pound sledge is all a striker can easily swing.
A power hammer delivers multiple blows with a bigger hammer. They range from 25 pounds to hundreds of pounds in hammer weight. The normal range for knifemakers is 33 to 100 pounds.
A press delivers many tons of pressure, witch is roughly equivalent to a very large hammer. Forging presses usually deliver a fairly quick force of around 40,000 pounds (20 tons). This is a lot of energy, but you only get a few presses at welding heat before the mass drops below the fusion point.
A rolling mill squeezes the metal from both sides and delivers a very intense addition of energy at the rollers. This is the most efficient way of reducing thickness or welding laminated ... but not practical for small shop knifemaking.

If a hammer was big enough, theoretically you could weld at room temp. In practicality, the steel has to be at least 1600°F to weld with a giant hammer or rolling mill.

The range where the atoms can move enough to fuse but not mush the billet apart is roughly 1600°F to 2300°F. For most hand forgers, the upper limit of 2200-2300F is the advised range, For those with a press or power hammer, 2100-2200°F is better. I would suspect that the big places with giant 500 pound hammers and 100 ton presses go down as low as 1800°F.

The sweet spot for welding is a temperature where the steel is still solid enough to survive the pressure of welding, but not so high that the grains slide apart or fully melt. The exact temperature is almost always judged by eye and learned by experience on your set of equipment. The bigger the hammer or press, the lower the temperature of the billet can be. As the hammer or press delivers energy to the billet, the temperature rises. You can see this when forging. As the steel drops to a duller red, strike the bar hard with a hammer. You will notice the color jumps up a good bit at the spot impacted … and quickly drops back to the lower heat color as the energy gets dissipated into the surrounding steel.

All forge welded billets should get grain refinement procedures to lower the grain size. You need to both refine the grain as well as release any internal stress from the welding and reducing procedures. Everyone has their own methods, but they should include reduced cycling temperatures ending in a quench, This is best done as soon as the billet is reduced to the thickness desired and/or the blade rough shaped by forging. These procedures need to be done prior to the hardening quench to assure a blade with internal integrity.

Summation:
Metallurgically, the forging range of most knife steels is between 1600F and 2100F. If steel is in this range the damage to the grain is minimal and correctable. For forging you have enough energy in the steel for the task of moving the grains around to re-shape the billet as needed. For welding you need more energy. Picking a place where the steel's structures are still unaffected but the added energy fuses the weld is what you are shooting for. Start at what you think is the bottom of the range. If you can master that range and get solid welds, your blades will benefit. If the welds aren't solid enough with your methods and equipment, then raise the temperature. The only practical gauge is your eye.
Once the layers are bonded, lower the heat by around 100 degrees to work and solidify the billet. Proper stress and grain reduction should follow the welding and reduction .

May 5, 2019
Stacy E.Apelt

That’s a great read, I came across that post yesterday .
I decided to cut a piece of that 1075 bar just out of curiosity and did a fast thermal cycle & quench I broke it before tempering it just to make sure they sent me carbon steel. I sanded it to a fast 600 then I did the acid etch, cleaned with 2500 grit. I’m not sure what to think of the results, I have performed this test with carbon steel a few times and they always come out solid dark gray, this bar…. Not so much.
Let me know what you think and thanks again for your time.

 

[Cushing H.]

Following. Total ignorance here - but what happens if you take that 1075 through several normalization cycles? Basically i am wondering if that stippling is arising from phase/grain inhomogeneities or if it is material contamination?

Stacy - it has been 1084 not 1075 that has recently been discussed as having quality issues related to heat treat, right?

 

[Willie71]

Is this Admiral 1075? I saw someone had problems last week on a Facebook group, had the steel tested and it was 0.2% carbon.

 

[Dan727]

Is this Admiral 1075? I saw someone had problems last week on a Facebook group, had the steel tested and it was 0.2% carbon.

Hi Willie, I don’t know if it’s the steel yet but it’s giving bad vibes for now. The supplier is in NJ, I have been using them for a long time and it’s the first issue I have had. I will reserve judgment until people with bigger brains than me has a look, I’m will to follow any advice to test it further.

 

[DevinT]

Your welding temperature is too hot.

Hoss

 

[Dan727]

Your welding temperature is too hot.

Hoss

Hi Devin, it’s possible for sure. When I set the welds I do it 3 times, I use a propane forge and the first is by hand and the next 2 times is small bites on my press. Then I turn the heat down so it never gets (white hot) again, until the next forge weld that is. This was around 400 layer.
The sample piece of the 1075 bar wasn’t welded and it doesn’t look right to me, I will keep reading and searching.
Thanks for all the advice & help guys, it’s much appreciated. I’m getting old but I will never be to old to learn.

 

[Stacy E. Apelt - Bladesmith]

I agree with Devin, the welds were probably too hot.
Also. you said that you used a press on the second and third weld. A press weld should be done about 100°F lower than a hand hammer weld.

Those photos don't look like you took it down enough, and didn't fully sand each grit out.

To really see what the surface of the test bar looks like you have to grind it down past any surface conditions and decarb. I would take a good .005 off and see what it looks like after sanding and etching. Sand each grit fully to remove the last grit lines.

 

[Dan727]

I agree with Devin, the welds were probably too hot.
Also. you said that you used a press on the second and third weld. A press weld should be done about 100°F lower than a hand hammer weld.

Those photos don't look like you took it down enough, and didn't fully sand each grit out.

To really see what the surface of the test bar looks like you have to grind it down past any surface conditions and decarb. I would take a good .005 off and see what it looks like after sanding and etching. Sand each grit fully to remove the last grit lines.

That makes sense, I will grind that sample piece tomorrow and re etch it. If it comes out clean then I probably did as you said. I will follow up either way.
Thank you very much for your advice Stacy.

 

[weo]

Out of curiosity, if you have a press, why are you setting the weld by hand? Flat dies on the press should set the whole billet in one squish.

 

[Mecha]

If a hammer was big enough, theoretically you could weld at room temp. In practicality, the steel has to be at least 1600°F to weld with a giant hammer or rolling mill.

Sounds like explosion welding.

 

[Dan727]

Out of curiosity, if you have a press, why are you setting the weld by hand? Flat dies on the press should set the whole billet in one squish.

Hi Weo, when I started making Damascus it was all by hand, I just stayed with low layer count & twist. For me it just feels good to set it myself before getting help from the machines.

 

[Dan727]

I agree with Devin, the welds were probably too hot.
Also. you said that you used a press on the second and third weld. A press weld should be done about 100°F lower than a hand hammer weld.

Those photos don't look like you took it down enough, and didn't fully sand each grit out.

To really see what the surface of the test bar looks like you have to grind it down past any surface conditions and decarb. I would take a good .005 off and see what it looks like after sanding and etching. Sand each grit fully to remove the last grit lines.

After doing a better job cleaning that test piece of 1075 it looks normal.
Thanks again for your time guys

 

[weo]

For me it just feels good to set it myself before getting help from the machines.

Ok, but you might be 'risking faulty welds, burned knuckles , and burning more fuel than necessary. Also, when you get more into pattern development, the press will help keep the layers even much better than doing it by hand.

 

[Stacy E. Apelt - Bladesmith]

I would keep the blade. You might want to sand it a little more to see if the pattern changes any.

 

[Dan727]

Ok, but you might be 'risking faulty welds, burned knuckles , and burning more fuel than necessary. Also, when you get more into pattern development, the press will help keep the layers even much better than doing it by hand.

Yeah, I might switch at some point to all press. I will try some mosaic down the road because I love a challenge.

 

[Dan727]

I would keep the blade. You might want to sand it a little more to see if the pattern changes any.

Thanks Stacy, I will do that. I did hack on a piece of 2x4 thinking it would break but I got tired before anything happened so it’s still alive lol