Hello Brian, about the only way short of some destructive type testing, or possibly some fairly expensive non-invasive methods, would be if you are fortunate to be able to "see" some of the rolling lines on the surface of the material. Possibly looking at the sheen of the surface from an angle and watching some reflected light from the surface may reveal some of the rolling lines. Even this would depend heavily on the condition of the material(how new, type and thickness). Do you have access to any of the drop from the part, similar to a jig-saw puzzle, you might be able to determine orientation from the pieces of drop or the skeleton if this is a burned part. If this is an issue for you in the future and these are outside parts that have been processed by someone else you should request that they identify the direction of rolling. If this is an issue due to material type and application, you may need to specify up front the orientation of the part with regard to how it is cut with consideration for the rolling direction. If this is an in-house part you will likely need to apprise your people of this importance and possibly incude this information on the cut-list and possibly include a double ended arrow symbol on the part to indicate the direction of rolling.
You may also wish to use the search function of the forum. I know there have been threads in the past that have dealt with similar questions and it is highly likely that there may be answers there that I have either mis-interpreted or have skipped over in reading about them. Good luck and best regards, aevald
i don't have access to the drops. and since the importance of the rolling direction has come to light, we have notified our supplier of the requirements.
when i examined the plates in question i noticed long lines in the mill scale that could indicate rolling direction. but not knowing the handeling these plates have recieved since they left the mill, i can't assure myself that these marks wern't made at a later time.
so i carefully removed some mill scale with a power brush, and i noticed what appear to be stress marks on the surface of the descaled steel. these marks are wavy and are transverse to the lines that appeared in the scale. to me the look like they could have been created by the rollers when this plate was pushed through it, in my mind reafirming what the lines in the mill scale was indicating.
any of that make since?
On TMCP plate you can use UT by using the pitch-catch method. I recommend using 70 degree probes. Set them up for one skip distance in each direction. The rolling direction will have a longer sound path (i.e. actual angle of transmission of greater than 70 degrees).
Mankenberg
i do have utII but unless i had someone to physically show me this method, i would not be comfortable using it.
It is actually pretty straightforward. Use a 70 and set up a screen range large enough to accomodate a full skip distance with 70 degrees. Then get a second 70 degree transducer & hook them both up to your scope. Set the scope to pitch/catch. Crank in some gain. Put the two ducers next to each other and pointing at each other on the plate, and start moving them away from each other until you get a signal. Max the signal, and note the sound path distance (optional but probably not necessary is to use your gain control to set the indication at a standard screen height, say 50% or 80% FSH).
Then put the two transducers on the plate in a direction perpendicular to the one you just did and repeat the process. You will find that the rolling direction is the one that has a longer sound path (and in fact it may be fairly dramatic), as the actual angle of sound transmission in TMCP plate is greater in the direction of rolling.
Note - this doesn't work for normalized or Q&T plate as the heat treatment refines the grains and the ultrasonic characteristics are pretty similar between the two directions.
Mankenberg
You can polish and etch the surface, examine to determine what direction the grains are elongated.
we would have to have it sent out to be done, and it would not be local.
since we are already cuttting the shipping date close, i doubt i could get them to agree to it.
Are there any mill markings on it? If yes, the heat number writing is usually written parallel to rolling direction. Some mill markings are a dot matrix type of indenting that can be hard to see, but it's written the same way.
One caution, supplier's marking can go either way depending on their inventory system - don't confuse them. Most often, the supplier's marking are written across the ends (transverse to the rolling direction). But that depends on where the warehouse employee was standing at the time so that's no guarantee.
If the plate began life as coil, you might see fine lines in the mill scale - those usually are transverse to rolling direction. (Coil flattens out and leaves telltales similar to bending a plate in a brake.)
If you can see an elongated mill rolling dent or dimple, or a series of them, or even a line, that can give you a clue as well.
Scrape marks on the surfaces are not reliable indicators; fork trucks can come from any direction.
I will not discredit any of the previous posts, those are some pretty sharp guys who have responded. I will ask you though, will your customer accept testing done after the fact as proof? Most customers have no sympathy for not being able to identify rolling direction and they do not want to take the time to prove to their higher-ups that the testing is reliable. Just a thought to consider.
i can't find any markings (mill or wharehouse) on these plates.
this building is a federal courthouse in rockford,ill. so it falls under fema 350. i am being told that the site inspectors will be checking rolling direction (how i don't know) and it is not how they want it they will reject it.
Chet
Remember that 3 inch FCM toggle plate for NYSDOT that you had back in '05, when I was the QA inspector? The mill told us that the punched in material id was parallel to the direction of rolling. We both went out there, they flipped the plate over and the punched in id was catty corner?
Joe, I had forgotten about that but remember it clearly now that you mentioned it. I think I have pictures somewhere -that was strange for sure.
I hate to feel I need to use "weasel words" but that's why I say "usually", "from what I have seen" and phrases similar to that. There is always an exception somewhere.
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