More 1084 weirdness

My question is what is causing this failure. Is it using a low budget mill. I how does that happen. I’m not that familiar with how steel is made besides the basics.
 
Had the same issue with 1095 about a year ago. Made me afraid of using simple carbons steels because I'm still fairly new to knifemaking. I switched to stainless now and hopefully don't have to worry about this anymore. I have about 8 bars of 1095 now that I don't want to waist my time messing with that will likely becomes templates for new models now.
 
There are much more experienced people in this discussion than I, but here's my thinking for consideration-

Etching tells us:
Boundary between martensite and not-martensite

Etching does not tell us:
Whether the soft spots fully austenitized
Whether the soft spots are deficient in carbon (? - see below)
Whether the soft spots have tramp elements
What the cooling rate in the soft and hard spots was

However, we can look at the patterns and note some interesting phenomena:
The tip appears to have hardened relatively well
A narrow perimeter of the blank appears to have hardened relatively well

Please correct me if I'm misunderstanding something here.

Additional question: are there other etchants that would tell us more info? Is there enough gradation in etching between pearlite and ferrite to identify variance in carbon content?
 
Nick Dunham said:
There are much more experienced people in this discussion than I, but here's my thinking for consideration-

Etching tells us:
Boundary between martensite and not-martensite

Etching does not tell us:
Whether the soft spots fully austenitized
Whether the soft spots are deficient in carbon (? - see below)
Whether the soft spots have tramp elements
What the cooling rate in the soft and hard spots was

However, we can look at the patterns and note some interesting phenomena:
The tip appears to have hardened relatively well
A narrow perimeter of the blank appears to have hardened relatively well

Please correct me if I'm misunderstanding something here.

Additional question: are there other etchants that would tell us more info? Is there enough gradation in etching between pearlite and ferrite to identify variance in carbon content?
Click to expand...

Etching is not a replacement for Chemical analysis and Micrographs.

Without further information to rule things out no one will know, problem is its just not worth the time or money.
 
Given the issues from the past year or two, and current problems, might it be a good, standard practice to only buy from a source providing "real" certs/analysis?
 
DanF said:
Given the issues from the past year or two, and current problems, might it be a good, standard practice to only buy from a source providing "real" certs/analysis?
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Only here on bladeforums I read about problems like this one ...My friend have multimillion-dollar machine shop and he use tons of steel for production every year...NEVER , never in my life I heard him complain that he get bad steel ...Obviously you have problem only with knife supplier steel company ...Maybe if you get steel from other , more serious source problem will disappear.
 
DanF said:
Given the issues from the past year or two, and current problems, might it be a good, standard practice to only buy from a source providing "real" certs/analysis?
Click to expand...
Dan ,I care only about my auto service shop and my customers . If you don t give me what I ask from you /quality parts / no more business with you .And I will inform colleagues not to do business with them .....
 
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Photo%20Nov%2006%2C%202%2051%2010%20PM.jpg


Evidence etched like hamon; hardness tested like hamon; hamon like hardness gradient from tang hole 3 times and full hardened perimeter, therefore most likely be auto hamon. If auto hamon is unwanted and want a full hardness blade, need to resolve quench cooling issue. Test: re-ht one blade with similar profile using interrupted quench 1.5 second in brine then oil(any sub 15s oil will do).
 
Issues in batches of metals do happen. That's why the industry standard is to make sure everything has certs and is traceable. If it was possible to trace this piece the seller could take this problem back to the mill.
 
Storm W said:
Issues in batches of metals do happen. That's why the industry standard is to make sure everything has certs and is traceable. If it was possible to trace this piece the seller could take this problem back to the mill.
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If someone had the MTRs, we would already know the composition, too.
 
DevinT said:
Shows that it is not homogeneous. Dark areas are tempered martensite, the light areas are mostly ferrite, the medium areas are pearlite. Not really sure how this happens. I don’t know enough about solidification to give an answer here.

Hoss
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If the dark areas are tempered martensite, why would they correspond with the softer HRc tests? Shouldn't the dark areas test the hardest if that was the case?



Don Hanson III said:
It used to be rare to have problems with new known steel. Now it seems more common. Weirdness.
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The two best titanium alloys I've worked with (by far) are both older, from the '90s or earlier.

What does that mean for this thread? Nothing, but I'm sayin' it anyway. :p
 
I don t know . . . . . . If this blade is HT by novice not by someone like JT I would say IF steel is good ....too hot quench oil, not agitated quench oil or steel =vapour jacket=uneven hardness, too refine grain in some places , submerged only blade first second and keep it still so vapour jacket act as shields an rest of blade /handle part / get cooler ...
 
Mecha said:
If the dark areas are tempered martensite, why would they correspond with the softer HRc tests? Shouldn't the dark areas test the hardest if that was the case?





The two best titanium alloys I've worked with (by far) are both older, from the '90s or earlier.

What does that mean for this thread? Nothing, but I'm sayin' it anyway. :p
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Well, it's not a 3 dimenional etch, only 2 dimensions :p
 
I will say that it was quenched in parks 50 and agitated up and down till it stopped smoking and then between plates.
 
I have noticed recently with some decent size W2 Bowie's I've been working on. I also use P50 to quench. I don't know why it happens but if I agitate it in the quench.... I always get auto hamon all over and way to close to the edge..... To where I have to reheat treat it cause its to close to the edge. Also the Bowies are full flat ground and .030" at the edge pre heat treat. And it still auto hamons close to the edge. But if I don't agitate it in the quench..... everything works out the way I want it too. Doesn't make sense to me but this has happen a number of times to me
 
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