1084 grain size?

Sando said:
Thanks for checking in on that Joshua Fisher Joshua Fisher . I should have contacted them myself, but I assumed it was all on my side. Pops is a great place and love doing business with them.

FWIW I also tried Robert Erickson Robert Erickson 's idea and heated to forge temperature.

2000 30 minutes, oven cool to 1400, then air
1525 25 minutes, air cool
1365 15 minutes and slow cool.
1475 10 minutes, quench

It looked the same.
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The first schedule I’m going to run will be 1650 to normalize then two grain refinement cycles at 1450 then hardening at 1475
 
Joshua Fisher said:
Hey guys, I was up at Pops this weekend and we looked into this and confirmed some of the grain issues and they have already reached out to the supplier who is reaching out to the mill to see what can be done and where things went wrong. It should have been in a good condition to go straight into hardening, Pops has pulled the steel from their site until a resolution has been reached and asked me to post here on their behalf to let everyone know they are doing what they can to make this right and are happy to work with people who picked up some of this steel. They also gave me a couple bars to take back to my shop and do some more testing to come up with a good schedule for the material already on the market. I’ll be sure to post back here with updates.
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How do we know if we have that steel?
 
Crag the Brewer said:
How do we know if we have that steel?
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They had it labeled as premium 1084 from Sheffield. It was not 1084 from njsb but I don’t know if it was produced at the same mill, it may not as I know the Sheffield supplier gets materials from a few mills and does some of final rolling and finishing in Sheffield. It also only came in 40” lengths compared to 48” lengths for most steels available here in the US minus cpm steels that come in 36” long
 
As a rule of thumb, what should be the grain size of 1084 steel supplied as "Hot Rolled Pickled Annealed"?
 
Way-Barney said:
As a rule of thumb, what should be the grain size of 1084 steel supplied as "Hot Rolled Pickled Annealed"?
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In my opinion it greatly depends on what the supplier or mill says the condition of the steel should be in. If the mill says it’s going to be a coarse state and you know it will need thermal processing before hardening and they provide a suggested schedule for getting it ready to harden then that’s one thing, if the mill says it should have a fine grain ready to harden then I would expect something completely different than the first scenario.
 
The fact that cycling is having no effect on the final fracture grain makes me think it isn’t the state of the steel that is the problem. Unless it’s completely mislabeled.
 
Thanks for taking the trouble to reply.
I would be checking oven calibration first to see if if I have a fault, in my usual "blame myself for any problems" mode.
 
FWIW:

I received a sample of 1084 from Alpha Knife Supply to compare. I also tried another steel from Sheffield called Shefcut (26c3 with niobium). This way I have two steels from Sheffield and two versions of 1084.


IMG_7110.jpeg

So from left to right:

Sheffield 1084 from previous tests (1525 normalizing, 1365 slow cool, 1485 10 minutes)
Sheffield "Shefcut" (1472 for 10 minutes, as prescribed)
AKS 1084 (1500 for 10 minutes, as prescribed)

I must say that Shefcut stuff looks great. I'll have to make a test knife soon.

In any case, I'm looking forward to Pop's getting it resolved.
 
20230807_204857[1].jpg
I just snapped a blade I made at the weekend from Sheffield made1084. (UK Supplier)
Target was ASTM 14 grain, tempered to target of 64.
When checked through a 20x jewelers loup it is possible to make out very very tiny grains, without the loup it is impossible to see any structure at all
thickness there is 2mm
The irregularities look like the fracture planes, I hope .
The blade was a little "springy", I was happy with it. at a guess I would say it broke about 15-20 degrees bend in the vice.
:)
 
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Sando said:
Thanks for checking in on that Joshua Fisher Joshua Fisher . I should have contacted them myself, but I assumed it was all on my side. Pops is a great place and love doing business with them.

FWIW I also tried Robert Erickson Robert Erickson 's idea and heated to forge temperature.

2000 30 minutes, oven cool to 1400, then air
1525 25 minutes, air cool
1365 15 minutes and slow cool.
1475 10 minutes, quench

It looked the same.
Click to expand...
Hmm yea it sounds like a bigger issue than coarse spheroidized condition.
I'll be curious to see how this resolves.
 
Way-Barney said:
Are there any updates on this?
Was the free steel the same?
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I ran quite a few samples using various schedules to try to refine the grain, from standard procedures to running high heat cycles then refining down and nothing was able to get the grain right. I spoke with the guys at pops the other day to see if they had an update and it sounds like currently we are waiting to hear back from the mill that produced the steel to see what went wrong. It sounds like the UK supplier ran similar tests and came to a similar conclusion that we reached that there’s something wrong with the steel from the mill. I know they guys at pops pulled the product from their site and are considering it a lose, I’d likely reach out to them if you have a bar of the Sheffield 1084. I personally wouldn’t recommend using it for a knife. Wish we had better news and I apologize for the delay in getting back to this thread but I wanted to make sure we had tried everything possible to make this steel work before posting a reply.
 
Joshua Fisher said:
I ran quite a few samples using various schedules to try to refine the grain, from standard procedures to running high heat cycles then refining down and nothing was able to get the grain right. I spoke with the guys at pops the other day to see if they had an update and it sounds like currently we are waiting to hear back from the mill that produced the steel to see what went wrong. It sounds like the UK supplier ran similar tests and came to a similar conclusion that we reached that there’s something wrong with the steel from the mill. I know they guys at pops pulled the product from their site and are considering it a lose, I’d likely reach out to them if you have a bar of the Sheffield 1084. I personally wouldn’t recommend using it for a knife. Wish we had better news and I apologize for the delay in getting back to this thread but I wanted to make sure we had tried everything possible to make this steel work before posting a reply.
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Did you try forging any? Wondering if it would be okay for pattern welding.

Hoss
 
DevinT said:
Did you try forging any? Wondering if it would be okay for pattern welding.

Hoss
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I tried bringing it up to 1900 to mimic forging and that didn’t help, I could try bringing it up to 2100 to mimic forge welding to atleast see if that would be a use for it but I don’t have high hopes.
 
Did anyone get an analysis? Do the bars come with requestable certs? Interesting supply problem.
 
fitzo said:
Did anyone get an analysis? Do the bars come with requestable certs? Interesting supply problem.
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I believe those are some of the details we are waiting on the mill to test/provide. Apparently they shut down for a couple weeks in August which has delayed any sort of response from them.
 
Joshua Fisher said:
I tried bringing it up to 1900 to mimic forging and that didn’t help, I could try bringing it up to 2100 to mimic forge welding to atleast see if that would be a use for it but I don’t have high hopes.
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Forging also reduces grain size, not just the high temperatures. I would be curious to see if it helps in this case.

Hoss
 
DevinT said:
Forging also reduces grain size, not just the high temperatures. I would be curious to see if it helps in this case.

Hoss
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Does the act of hitting the steel with a hammer refine the grain or the fact that most people will do several low heat planishing passes that could resemble grain refinement done without a hammer. I know large reductions like in the case of hot rolled steel versus cold rolled results in a finer grain. But if I remember correctly that requires significant reduction. Saying forging inherently reduces grain size is getting really close to “edge packing” theory. If I remember correctly Larrin even did an article saying the opposite that forging a knife to shape with how little reduction is happening and the multiple high heats is more likely to grow the grain. Again specifically looking at knife thickness and processes not large industrial level.
 
Joshua Fisher said:
Does the act of hitting the steel with a hammer refine the grain or the fact that most people will do several low heat planishing passes that could resemble grain refinement done without a hammer. I know large reductions like in the case of hot rolled steel versus cold rolled results in a finer grain. But if I remember correctly that requires significant reduction. Saying forging inherently reduces grain size is getting really close to “edge packing” theory. If I remember correctly Larrin even did an article saying the opposite that forging a knife to shape with how little reduction is happening and the multiple high heats is more likely to grow the grain. Again specifically looking at knife thickness and processes not large industrial level.
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Look up dynamic recrystallization.

Larrin did say that forging a knife from bar stock doesn’t do much but that is assuming the starting bar has fine grain.

I also asked if this material would be good for pattern welding which would require quite a bit of reduction.

And, lower your tone with me.

Hoss
 
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