Rolling direction of the steel sheet..

Got 320x250mm aeb-l sheet and asked for rolling direction of it..

Dealer stated;

"Unfortunately I cannot say which way this sheet was rolled. However,
they come to us in 320x1000mm sheets to us, and they are bent slightly
along the 320mm widht. Meaning that the rolls were likely 1000mm wide.

We cut the 320x1000mm into quarters, 320x250mm, and this would mean than
the 320mm side would be the rolled one. Cutting it may have affected the
bend (?), but check if its a bit off that way. "

Perhaps here are the photos I made:

Pic1

Pic2

Pic3

I can see surface marks as a lines perpendicullar to the imaginary axis around which the sheet is bent.
From wich I would judge the rolling orientation was not what I was told..

I never really worked in the steel mill but I know well these are delivered in coils and then uncoiled..
I assume orientation of coiling and rolling to be the same one.

Is there anything I forgot to consider except not believig the dealer ?

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Two questions:

1. Why exactly are you concerned about which direction it was rolled in?

2. How do you know that the material is "delivered in coils and then un-coiled"?

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Ryan Nafe
Two questions:

1. Why exactly are you concerned about which direction it was rolled in?

2. How do you know that the material is "delivered in coils and then un-coiled"?

For the 1st time ever decided to make 1 or 2 fighters with blade about 8".. so wanna be sure
it will be as difficult to snap them in half on impact as possible..

Its common with this class of steel.. sandvik

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Ryan Nafe
Two questions:

1. Why exactly are you concerned about which direction it was rolled in?

It effects the toughness in the same way it does with wood.

Imagine splitting a piece of wood through the grain and then with it.

Many modern steels are cross rolled to avoid this kind of extreme divergence in toughness with/against the grain.

Cliff, have you heard of aeb-l being cross rolled ? It would definitely be nice..
But I think it isnt ;( I might ask BU..

Also I really wanna be sure I wont do any mistake with this. If You look at line marks
on the top of the steel sheet to me it means the steel was rolled same orientation
as long straight surface scratches and discolorations show, right ?
Especially if the steel bend is supporting this guess..

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I showed pics to friend metallurgist and he confirmed my estimation.
It was rolled in the same direction as dark lines on the top are.

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JSCT
Its common with this class of steel.. sandvik

Ok thanks, I wasn't aware that that was a thing. I never see that in industry so I was skeptical, but I'm also far closer to the consumer end of the chain than the raw material end.

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CliffStamp

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Ryan Nafe
Two questions:

1. Why exactly are you concerned about which direction it was rolled in?

It effects the toughness in the same way it does with wood.

Imagine splitting a piece of wood through the grain and then with it.

Many modern steels are cross rolled to avoid this kind of extreme divergence in toughness with/against the grain.

Ok, thanks Cliff.

This does raise another question though:

- Does rolling (either cold or hot) actually produce the grain direction?


I was under the impression that grain direction was already present before the rolling, but then I started thinking about cast steels and I lost the plot because I can't see how the grain direction would be present without being directly influenced by the casting process itself.

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Ryan Nafe

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JSCT
Its common with this class of steel.. sandvik

Ok thanks, I wasn't aware that that was a thing. I never see that in industry so I was skeptical, but I'm also far closer to the consumer end of the chain than the raw material end.

Originally it was supposed to be tougher along 320mm side.
I ve made a CAD file for waterjet with 8 blades in it.
Then the steel was delivered, I look at it and it doesnt look like what dealer
said.. And was tougher along shroter 250mm dimmension. Couple of blades were longer
and did not fit in 250mm even w slight rotation.. So had to make a new design with shorter blade
160mm instead of 200mm and then make a new whole CAD file with positioned all blade
blanks for waterjet cutting. Some 6+h of work that had to be done twice.. Just because
I relied on the salesmen who was wrong. So dont be like me anyone
and learn from this. !

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I don't know how you can tell how the steel was rolled. on two different pieces of ground flat stock from two different makers, light sanding of the marks going right to left reveal marks going up and down. so who knows.

scott
[www.etsy.com]

Is there anyway to polish and etch the steel to check the grain of the steel?

---------------------------------------------------------
Stone Sharp Edges
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"I am still discussing issues of steels and performance at this stage.

-Cliff"

"Roman Landes said:
Cause geometry cuts, .....steel determines the level and the duration"

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jasonstone20
Is there anyway to polish and etch the steel to check the grain of the steel?

I would think so. On some kinds of sheet metal, mostly dependent on the surface finish, you can tell the grain direction under good lighting. The best way I know to check in the context of my profession is to bend it in a press brake. Bending it perpendicular to the grain will give much more consistent angles and usually requires slightly more force than bending parallel to the grain.

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oldsailorsknives
I don't know how you can tell how the steel was rolled. On two different pieces of ground flat stock from two different makers, light sanding of the marks going right to left reveal marks going up and down. so who knows.

Sheet was not yet surface ground - its as rolled - coiled - uncoiled.
Switch links page into english, download photos by selecting button "download slow"
and zoom to see surface and bend.

because its strip steel its very unlikely it can be cross rolled.. but only my guess..

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jasonstone20
Is there anyway to polish and etch the steel to check the grain of the steel?

rather to cut thin samples ht them ans try to break..

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Ryan Nafe
Ok, thanks Cliff.

This does raise another question though:

- Does rolling (either cold or hot) actually produce the grain direction?

Exactly. This is why artisans have developed a special hand forging techniques
to improve steels mech properties by producing the grain direction as desired
to make steel harder to break in certain direction.. They learnt this by experience
thousands of years ago before steel was made in factories.

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Corbet Sigman made cross grain 440C blades a long time back, and he appeared to get more toothy edges.
Two of us makers did the same and we got more toothy edges.

I am now aware that the blades might be weaker, but they were knives, not prybars.

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Stuart Ackerman
Corbet Sigman made cross grain 440C blades a long time back, and he appeared to get more toothy edges.
Two of us makers did the same and we got more toothy edges.

I am now aware that the blades might be weaker, but they were knives, not prybars.

What You descibed is: higher carbide steel finished to lower grit to have more toothy edge
and microstructure that is perpendicular to the cutting edge will allow some microchiping
that will help to cut longer fibery materials at slicing motion.
This perhaps also lowers the edge stability at low angles.
Only good for light use knives.

Perhaps the knife I had that in concern is AEB-L fighter where I need higher
edge stability and toughness to resist high velocity impacts.
Also If I would want to use more toothy edge I wouldnt use AEB-L
but some coarser steel like D2 etc..

Perhaps even for extremely light use geometries like kitchen petty knives
where I grind extremely thin tips and full distal tapers:
I make blades at the same direction with rolling as otherwise the thin tips will become
too easy to break off (less than last 1mm usually)

EDIT:

So If You think of a fact that this allows me to make thinner knife
yet not to be too weak to fail I actually make something with higher
cutting ability.

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Edited 1 time(s). Last edit at 06/18/2018 04:48AM by JSCT.