Does rolling direction matter?

[mete]

My experience in steels in general , that toughness , especially conversion from lab tests and actual parts is not an exact science ! My experience in actual use when I can compare transverse vs longitudinal grain there can be very meaningful differences !.In the newer and better steels there is less of a problem.

 

[Mecha]

I'd bet that the longer and thinner a blade is, the more it could matter.

 

[Larrin]

Thanks, I checked some other steels, and the only ones I could get comparative LvsT were the high alloy stainless steels. Above S30V, the transverse rises. The LvsT for CPMS35VN was very good .... probably why I never saw any issue.
http://www.crucible.com/PDFs\DataSheets2010\dsS35VNrev12010.pdf

Can you find the data sheets with the Charpy tests LvsT for steels like 52100, 1095, and 5160?

What I was referring to in my comments about a knife geometry not being apples to oranges is that the shape and very thin edge of a knife will yield to a blow far below the transverse yield point of a Charpy test. Even 3 to 4 joules is a big blow to a hardened blade.

I will amend my comment about deliberately cutting across the grain.

Simple carbon steels or alloy steels have relatively low carbide volumes and the carbides dissolve at low temperatures so they are less affected by carbide distributions; impurities are still a factor, of course.

 

[nsm]

We cross roll (Typically rotated 90 degrees 2 to 3 times during the rolling process) titanium and aerospace alloys all of the time to meet tensile and bend test requirements. We could do the same for CPM if we knew it made a measurable difference. The CPM billets we buy from Crucible are 11 to 14" wide and 4 to 5 " thick when they start out and we roll them in multiple directions to get them out to 26 to 28 inches wide. It's kind of like rolling dough, except it's really hot, a lot harder and our rolling pins are 24 inches in diameter and weigh 6 tons each. Once they get to .500" thick we stop rolling, anneal the plate, shotblast to clean the surface and then finish roll in one direction to get the length and thickness. The final roll direction for CPM is along the 36 " dimension. I can assure you, our steel gets rolled in more directions than just about anyone else in the world.



Bob Shabala
President
Niagara Specialty Metals

 

[mete]

Bob, thanks for that information. It saves me from guessing !

 

[Stacy E. Apelt - Bladesmith]

Thanks Larrin and Bob.

 

[Alpha Knife Supply]

The CPM billets we buy from Crucible are 11 to 14" wide and 4 to 5 " thick when they start out and we roll them in multiple directions to get them out to 26 to 28 inches wide. It's kind of like rolling dough, except it's really hot, a lot harder and our rolling pins are 24 inches in diameter and weigh 6 tons each. Once they get to .500" thick we stop rolling, anneal the plate, shotblast to clean the surface and then finish roll in one direction to get the length and thickness. The final roll direction for CPM is along the 36 " dimension. I can assure you, our steel gets rolled in more directions than just about anyone else in the world.

Bob Shabala
President
Niagara Specialty Metals

Thank you for the information. I appreciate you taking time to describe your processes.

Chuck

 

[Willie71]

We cross roll (Typically rotated 90 degrees 2 to 3 times during the rolling process) titanium and aerospace alloys all of the time to meet tensile and bend test requirements. We could do the same for CPM if we knew it made a measurable difference. The CPM billets we buy from Crucible are 11 to 14" wide and 4 to 5 " thick when they start out and we roll them in multiple directions to get them out to 26 to 28 inches wide. It's kind of like rolling dough, except it's really hot, a lot harder and our rolling pins are 24 inches in diameter and weigh 6 tons each. Once they get to .500" thick we stop rolling, anneal the plate, shotblast to clean the surface and then finish roll in one direction to get the length and thickness. The final roll direction for CPM is along the 36 " dimension. I can assure you, our steel gets rolled in more directions than just about anyone else in the world.



Bob Shabala
President
Niagara Specialty Metals

Will you roll to thinner than 1/2"? You have some steel I would like to try, but 1/2" isn't very workable for my purposes.

Warren

 

[Stacy E. Apelt - Bladesmith]

.... Once they get to .500" thick we stop rolling, anneal the plate, shotblast to clean the surface and then finish roll in one direction to get the length and thickness. ....