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New micrographs of 42 knife steels
Posted: Mon May 27, 2019 8:18 am
by Larrin
I polished up and etched a whole bunch of different knife steels and took micrographs of them, including many that have been used in Spyderco knives, of course. I show the differences between steels on a microstructure level and explain how the carbide structures contribute to the properties found in different steels.
https://knifesteelnerds.com/2019/05/26/ ... fe-steels/
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 8:53 am
by Enactive
Very cool, Larrin! Thanks so much for doing this work and for sharing it so generously.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 12:07 pm
by Larrin
Enactive wrote: ↑Mon May 27, 2019 8:53 am
Very cool, Larrin!
Thanks!
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 12:25 pm
by AshK
Great work thanks mate. Your site is helping me learn a lot.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 1:23 pm
by SpyderEdgeForever
Thanks, Larrin. What do you say to this? Someone once told me (an engineer) that when he looks at micrographs of steel, what interests him the most are the tiny needles such as the iron whiskers. He said if mankind learned to cheaply mass produce those they would be better materials for knife blades than the actual steel they are found in.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 1:39 pm
by Larrin
SpyderEdgeForever wrote: ↑Mon May 27, 2019 1:23 pm
Thanks, Larrin. What do you say to this? Someone once told me (an engineer) that when he looks at micrographs of steel, what interests him the most are the tiny needles such as the iron whiskers. He said if mankind learned to cheaply mass produce those they would be better materials for knife blades than the actual steel they are found in.
You asked me about iron whiskers once before:
viewtopic.php?f=2&t=82271&p=1290884&hil ... s#p1290884
The problem with whiskers is the bigger they are the worse their properties are. It's not theoretically possible to make them behave otherwise as far as I know.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 1:51 pm
by koenigsegg
Larrin I know it's not a knife steel so maybe you don't feel like you can cover it but I've recently learned of SX500 Superalloy and how they keep part of the metal molten while part is cooled so they can grow it all into one crystal. Would really like to know more about this stuff I think it's got a lot of Be in it. EIther way thanks for your posts, I enjoy supporting you through patreon and getting all the articles early. Thanks for all your work
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 2:46 pm
by Blades
Very cool!
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 3:21 pm
by Larrin
koenigsegg wrote: ↑Mon May 27, 2019 1:51 pm
Larrin I know it's not a knife steel so maybe you don't feel like you can cover it but I've recently learned of SX500 Superalloy and how they keep part of the metal molten while part is cooled so they can grow it all into one crystal. Would really like to know more about this stuff I think it's got a lot of Be in it. EIther way thanks for your posts, I enjoy supporting you through patreon and getting all the articles early. Thanks for all your work
I’m not a superalloys expert. I don’t have any and it probably requires a different etchant. It would be better to look for journal articles on the material.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 3:35 pm
by koenigsegg
Larrin wrote: ↑Mon May 27, 2019 3:21 pm
koenigsegg wrote: ↑Mon May 27, 2019 1:51 pm
Larrin I know it's not a knife steel so maybe you don't feel like you can cover it but I've recently learned of SX500 Superalloy and how they keep part of the metal molten while part is cooled so they can grow it all into one crystal. Would really like to know more about this stuff I think it's got a lot of Be in it. EIther way thanks for your posts, I enjoy supporting you through patreon and getting all the articles early. Thanks for all your work
I’m not a superalloys expert. I don’t have any and it probably requires a different etchant. It would be better to look for journal articles on the material.
OK sorry
DIdn't really mean to etch it just curious about it but I will look else where
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 4:12 pm
by Larrin
There is no need to apologize. You can't see the microstructure without etching.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 5:51 pm
by kodai78
Thanks for the hard work and the link.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 6:48 pm
by The Meat man
Thanks Larrin, I really appreciate your work and your willingness to share!
Do you have any estimate of carbide volume percentage for Maxamet?
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 7:01 pm
by Larrin
The Meat man wrote: ↑Mon May 27, 2019 6:48 pm
Thanks Larrin, I really appreciate your work and your willingness to share!
Do you have any estimate of carbide volume percentage for Maxamet?
I will do the point counting tomorrow if I remember. It’s a pretty simple procedure. Look up point counting and you can even try it yourself.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 7:23 pm
by koenigsegg
Larrin wrote: ↑Mon May 27, 2019 4:12 pm
There is no need to apologize. You can't see the microstructure without etching.
Yes, what I meant was me bringing up the steel wasn't about etching or making micro graphs I just thought maybe you could cover the steel in an article that's all I was asking but like I said no worries you don't seem to want to explore it
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 7:53 pm
by The Meat man
Larrin wrote: ↑Mon May 27, 2019 7:01 pm
The Meat man wrote: ↑Mon May 27, 2019 6:48 pm
Thanks Larrin, I really appreciate your work and your willingness to share!
Do you have any estimate of carbide volume percentage for Maxamet?
I will do the point counting tomorrow if I remember. It’s a pretty simple procedure. Look up point counting and you can even try it yourself.
Done. :cool:
Using your micrograph (and a sheet of graph paper), I calculate it to 34.55% carbide volume.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 8:06 pm
by Larrin
The Meat man wrote: ↑Mon May 27, 2019 7:53 pm
Done. :cool:
Using your micrograph (and a sheet of graph paper), I calculate it to 34.55% carbide volume.
Sounds a little high since Rex 121 was only 32% based on my point counting. I will see what I get tomorrow. Did you remember to count boundaries as 1/2 instead of 1?
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 8:07 pm
by Bloke
Very interesting!
As always Larrin, many thanks for posting. :)
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 8:09 pm
by The Meat man
Larrin wrote: ↑Mon May 27, 2019 8:06 pm
The Meat man wrote: ↑Mon May 27, 2019 7:53 pm
Done. :cool:
Using your micrograph (and a sheet of graph paper), I calculate it to 34.55% carbide volume.
Sounds a little high since Rex 121 was only 32% based on my point counting. I will see what I get tomorrow. Did you remember to count boundaries as 1/2 instead of 1?
No, the article I read on point counting didn't mention that. That would probably account for the high estimate.
Re: New micrographs of 42 knife steels
Posted: Mon May 27, 2019 8:14 pm
by Bloke
The Meat man wrote: ↑Mon May 27, 2019 7:53 pm
Using your micrograph (and a sheet of graph paper), I calculate it to 34.55% carbide volume.
Hey Connor, could you please check for any whiskers too?
