This is mild steel but does it mean anything about cold rolling and maybe relate to knife steel ?

This is 3/8 x 2" steelbar I used to make shackles for the Jeep. On examining it I thought it weird to see all the 'folds' . Is cutlery steel the same ?

 

Yes, cutlery steels are shiny sometimes too.

 

Thanks, you rock. can you see all the layers ?

 

I count at least 22 layers and the thicker black lines. dunno maybe bad flux or that crispy black layer included......

 

Are you looking at what you think are weld seams, or do you think they might be deformation banding as is common in rolled steels?

 

Yes I guess I am. I checked my 1/4 plate and found the same lines just thinner. I couldn't find it in the 3/16 plate. I guess since getting into knives my eye for steels is getting keener. Also I'm thinking of the metal more since this damn game show where they have to make a knife in a hour and are given the steels to work with Thanks, looking up deformation banding now.

 

Deformation banding is cool but not even close. maybe I'm looking at hot rolled steel.

 

How did you cut it?

 

I used an angle grinder. It was a clean cut. It flaps down nice I guess I just never noticed the lines.

 

So you haven't polished or etched?

 

I have to say to make clear. This is only on mild steel. I don't have any hi-carbon on hand. I just started to notice the lines where I guess it was rolled/welded together. pic with light flap in the middle. maybe i'm looking too deep but it's interesting.

 

Please polish the edge and etch in nital or ferric chloride or something, because your pictures don't seem to be showing anything of interest (other than maybe a scale inclusion or similar in that last pic).

 

What I think Robert is saying is that those lines are very unlikely to be welds....but polishing an edge to 600 or 800 grit, then etching it will tell us for sure. If those marks are as cut, and you cut it with an angle grinder, I'm not sure what exactly is going on.

What they look like to me is bandsaw tooth marks.

 

It's mild steel so etching it kinda moot. but I did and middle is 600 well minus the deep ones I used angle grinder and not bandsaw on an angle so could never be horizontal cuts. Thanks

 

So what are you seeing in the piece that's been polished and etched? You don't think etches are done on mild steel?

 

OK xoomy you're harsh but I think you're right. Maybe I'm looking at peices that have been bandsawed and I haven't put them together right. thanks. but I'm interested in the mild steel etching. I have ferric acid. what does that do for it and can I do something cool with it?

 

and Cris Thanks !

 

Etches can be used for different things but they are standard procedure when looking at steel microstructure...particularly under a microscope but sometimes larger structures like banding and weld seams are visible without magnification. That's why I recommended it.

Sorry to sound rude.

 

Those are saw cuts. Rolled steel is not laminar. There is no folding or welding, it is rolled progressively thinner.