[TheForge] Re: My three comments back from the dead

[Thomas A. Troszak]

Dear Scott,

The three quotes below that you are quoting originally came from me.

The first quote has been refuted several times already, thanks. I'm certain
that at your plant you rolled the bars, as you say. My understanding (or
lack thereof), was based on a conversation with one of my many steel
suppliers, who claimed that at HIS plant, the smaller dia. bars were in fact
drawn.  Perhaps he was just full of shit, he was after all just a salesman.
The larger rounds (6" and bigger) that I have purchased were turned and
polished from HR rounds, not rolled. In retrospect, It was obviously
ill-advised of me to repeat such spurious data without confirmation from a
first-hand source such as yourself, and I shall not quote others without
reference in the future. I have already stood re-educated on this topic
before. I am Most Certainly Re- Re-Educated Again, Thank You!




The second comment was meant to assert that after a given of CF bar has been
heated to 2000 Deg. F it feels and acts the same under the hammer as a given
of HR, and I stand firmly by this assertion, as it is my personal
experience. I don't think that you can say that I am "wrong" if I think they
forge the same. Maybe you can feel a difference, I can't.





The third quote is a stated suspicion that was also based on my personal
experience. I have purchased many bars of steel, and have had to scrap
thousands of dollars worth of CF bar that was purchased, cut, machined, and
then found to be defective under the smooth surface.  I got to the point
where I purchased a dye penetrant test kit, and I would literally climb up
onto the steel truck and check out every bar of CF material , or I wouldn't
even unload it. After inspecting many bars, I got so good that I could see
defects that the dye test missed, and I could just look at a bar (under the
grease) and tell if it was naughty or nice.

The steel distributors will not take $$$responsibility$$$ for the defects
from the mill.  I could have easily bought a $$$nice new truck$$$ with the
money I wasted on defective steel, and wasted machining. I used to keep a
gallery of sample chunks taken from defective bars to educate steel
distributor's salesmen about what I would or would not accept from them.
Each little (or not so little) chunk on the shelf represented at least a
thousand bucks down the drain. Sigh.

From your comments, in YOUR mill, apparently bars of HR steel were not
inspected or graded before consignment to cold finishing, just toss 'em
through. Great. Don't doubt you for a minute.

What my comment was intended to be was perhaps a wee dig at the careless or
malicious slobs at the (U.S.- made by the way) steel plant who allows such
screwed-up material to ever get on a truck and leave the mill in the first
place.  I am not the only manufacturer who feels this way.  I have met
several quantity steel users, who share my pet suspicion that cold finishing
is sometimes a lame attempt to pass off ridiculously inferior HR stock by
shmooshing it through a secondary process that turns it into a shiny B.S.O.
(bar shaped object) that is in no way usable as steel, yet can be greased up
and palmed off to an unsuspecting customer. Perhaps our suspicions were just
an attempt at rationalizing how anyone could "accidentally" produce such
crap. 

If our suspicions are "Wrong" as you attest, and this material is not
intentionally being "disguised", then the only possible explanation for the
repeated delivery of catastrophically bad material is either apathy or
stupidity on the part of the mill workers that would shove such unbelievable
crap onto a truck.

So, if you are right, then the steel manufacturers are not being malicious,
just criminally clueless, and either way it sucks and I want my money back,
dammit.

Thanks for your thoughtful comments!

Tom Troszak

 
> Message: 6
> Date: Sun, 19 Oct 2003 22:31:22 -0400
> To: theforge@mailman.qth.net
> From: Scott Lane <scotty@one.net>
> Subject: Re: [TheForge] Re: cold drawn steel
> Reply-To: theforge@mailman.qth.net
> 
> 
>> For what it is worth, I don't know of any steel products that are "rolled"
>> cold.  The "proper" designation for the material is "CF" which stands for
>> Cold Finished, and the hot rolled material is first descaled and then drawn
>> through a die to the finished size just like wire, and becomes work hardened
>> in the process.
> Wrong.  It is rolled.  I did it at the steel plant.
> 
>> Once it is heated past critical temperature, there is absolutely no
>> difference from the "hot rolled" variety. I have forged many pieces of CF
>> steel up to 4" dia., and once it is hot it forges exactly the same. It only
>> acts kinky when you are trying to bend at a dull red, then the stiff spots
>> show up.
> Wrong.  The surface of cold rolled is compacted during the rolling
> process.  I've had to check this in the micrographs while cold rolling
> stock at the steel plant.
> 
>> I have found that the quality of the cold finished bars tends to be inferior
>> to the hot rolled material, that is, I suspect the mill takes the bars that
>> are too ugly to sell in their "as rolled" condition, and sends them through
>> the cold finishing in the hope of making "sellable" product.
> Wrong.  It is the same stock off the line.
>