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.So what does hoss think after seeing it etched?
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?
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.
No , they should done that before they sell steel to me ! I pay for steel and except to get steel !the supplier should be paying for the analysis.
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.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?
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 .....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?
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.
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
It used to be rare to have problems with new known steel. Now it seems more common. Weirdness.
Well, it's not a 3 dimenional etch, only 2 dimensionsIf 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.