Stress fractures?

Justin Schmidt

Justin Schmidt

Joined
Feb 18, 2016
Messages
2,209
Been trying to learn 1095. I have a pid set up in my forge. I'm waiting on the solenoid and omega TC to get here. So I've just been using the TC that came with the pid. I can get it to hold within 10deg on the blown burner.
Normalized 3x 1800,1600,1475. Waited then applied satanite om the edge. Nothing crazy just some lines. Waited for it to dry then back in the forge. Soaked at 1475 for 8 min quenched in 7% brine. I know I know. But I just dont have the money for p50 right now. I had it set aside and stuff just came up.
Anyway, should I break it and check the grain?
koxaQgA.jpg
 
Thoes could just be surface cracks and might grind away when you grind the blades edge bevels
 
I ended up just breaking it because i wanted to see the grain. Grain looks great but I can see the fractures through the steel. Live and learn and invest in parks 50 :D
yDnZyok.jpg
 
Only time I have seen water/brine work on blades of high carbon is with interrupted quenches. I have not done it so I’m not much help. But I goes somthing like in for a count of x and out for a count of Y then back in for a count of z. Thoes times are dependent on steel type, geometry and experance. But I do know there are people that do it.
 
Yes, that is stress cracking.

Brine quench is a best and timing of the IN and OUT are critical. It is hard to learn and will break/crack a lot of blades.

You said, "Put satanite on the edge." ???? The clay goes on the spine area down toward the edge. The edge is left bare except for a thin wash of clay.

I'll give my brine quench procedure.
Make 7% brine and heat it to 120°F it should be a good size tank of it … at least several gallons.
Sand the blade to 400 grit with NO deep scratches.
Round the spine edges so they are not hard 90° angles. Avoid all sharp angles in the knife shape.
Give the whole blade a wash coat with very thin Satanite … about the consistency of a melted milk shake. Let dry completely ( hair dryer will speed up).
Coat the spine and down the side about 2/3 of the way toward the edge with Satanite mixed to the consistency of sour cream. The layer is thin … about .1"
The bottom of the clay should be in a slightly wavy line. ( Save the fancy hamon for when more experienced)
Let dry fully (hair dryer or overnight).
Heat to 1450°F (use lowest temp that will work for the steel) and let soak for 5-10 minutes.
Quench tip first in the brine and count IN-2-3, OUT-2-3, IN-2-3, OUT and let cool in the air. DON"T drop or bang the blade as it will shatter.
Gently, scrape off any remaining clay. DON'T try and "check the hamon" by grinding the blade and giving it a quick etch.
IMEDIATELY place in a 400°F oven to temper for 1 hour. You can sand off the rest of the clay and give a test etch now.
If all looks good, give the blade a second temper at the desired temper target. 450°F is a good one for W2.

When sanding off after the temper, be sure to remove all the decarb. The line you see at first is just the line where the steel under the clay was not as decarded as the steel exposed. This isn't the hamon. The real hamon is a bit below that line and "in" the steel, not on it.
 
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I did the interrupted quench when the customer picked the wrong steel and machined all the parts before finding out. He had many parts but he knew some would be lost.
I did lose some before I worked out the timing but most were saved . How many blades do you want broken ?
 
Stacy E. Apelt - Bladesmith said:
Yes, that is stress cracking.

Brine quench is a best and timing of the IN and OUT are critical. It is hard to learn and will break/crack a lot of blades.

You said, "Put satanite on the edge." ???? The clay goes on the spine area down toward the edge. The edge is left bare except for a thin wash of clay.

I'll give my brine quench procedure.
Make 7% brine and heat it to 120°F it should be a good size tank of it … at least several gallons.
Sand the blade to 400 grit with NO deep scratches.
Round the spine edges so they are not hard 90° angles. Avoid all sharp angles in the knife shape.
Give the whole blade a wash coat with very thin Satanite … about the consistency of a melted milk shake. Let dry completely ( hair dryer will speed up).
Coat the spine and down the side about 2/3 of the way toward the edge with Satanite mixed to the consistency of sour cream. The layer is thin … about .1"
The bottom of the clay should be in a slightly wavy line. ( Save the fancy hamon for when more experienced)
Let dry fully (hair dryer or overnight).
Heat to 1450°F (use lowest temp that will work for the steel) and let soak for 5-10 minutes.
Quench tip first in the brine and count IN-2-3, OUT-2-3, IN-2-3, OUT and let cool in the air. DON"T drop or bang the blade as it will shatter.
Gently, scrape off any remaining clay. DON'T try and "check the hamon" by grinding the blade and giving it a quick etch.
IMEDIATELY place in a 400°F oven to temper for 1 hour. You can sand off the rest of the clay and give a test etch now.
If all looks good, give the blade a second temper at the desired temper target. 450°F is a good one for W2.

When sanding off after the temper, be sure to remove all the decarb. The line you see at first is just the line where the steel under the clay was not as decarded as the steel exposed. This isn't the hamon. The real hamon is a bit below that line and "in" the steel, not on it.
Click to expand...


I actually used your 7% brine recipe you posted in another thread. Blade was sanded to 220 and I rounded all the corners also to 220. After talking with some people I'm pretty sure those are from cold forging.
I will definitely do your interrupted quench procedure and sand up to 400 this time. Yeah i ment put satanite on the spine it was late when i wrote that lol
 
1800f? 1095 is normalized at 1600f.
Your second “thermal cycle” was a normalizing heat. For 1095 that was forged or heavily annealed, my procedure would be to normalize at 1600-1650f, thermal cycle 1525f 1475f 1425f (I quench on last thermal cycle). 1475f 10 minute soak, P50 quench, temper.

130f canola hardens 1095, especially in 1/8” and under cross sections. You can even try 3 seconds into brine, then immediately into canola until ambient.
 
HSC /// said:
it does and will work just fine, and I'd be happy to hardness test your blades for you so you can feel comfortable using the warm canola.
Click to expand...

Hey I appreciate that man! I'll have to take you up on that offer.
Stuart I'll try that next time
 
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