Warning: The following material contains detailed technical discussions
of materials testing, and is only provided for those wishing to pursue
the subject. This is only a limited guide to some available resources,
and is intended for technical review. This information is NOT provided
to reflect on any strongly held beliefs on Ford production.
Bob Melusky wrote:
> I was not at this foundry in the 60's but have been on a few melt
> decks before and supplied the metallurgical equipment to count nodules.
>
> <--snip-->
>
> It is a lot of work to do this and I would be very surprised if Ford
> used 100% metallurgical inspection for a production part. The Hipo
> crank I had had a brinell hardness test on a counterweight. While
> this is a more manual test that requires a 10x optical measurement, it
> is fairly quick for an experienced operator and far more believable
> that the cranks were 100% brinell tested based upon my foundry
> experience.
>
> Bob Melusky
Bob,
I agree that Brinnell testing is a laboratory tool, and would seldom be
used in a high volume production line. Maybe a test of a structural
steel pour for lot raw material certification. Here are some
references, including picture, and "Operating Instructions":
"The Brinnell hardness tester uses an air supply to apply the desired
load to the specimen through the penetrator. The standard load is 3000
k, and the standard penetrator is a 10 mm diameter steel ball. The
hardness number is determined as the load divided by the indented area.
This can be calculated, but the usual procedure is to determine the
diameter of the penetration and use tables to determine the number."
(Picture here)
http://www.public.iastate.edu/~em327/equipment/brinnel.html
A more likely production tool would be a Rockwell Hardness test,
" The Rockwell hardness test method consists of indenting the test
material with a diamond cone or hardened steel ball indenter. Small,
portable test devices are available "
(Specs and Pictures)
http://www.gordonengland.co.uk/hardness/rockwell.htm
and
http://www.hardnesstesters.com/rockwell-hardness-tester.htm
Which also leaves indentations on a ground/polished surface, and is a
more suitable indicator of heat treat on a production item basis.
Conversion tables between various harness test methods are:
http://www.gordonengland.co.uk/hardness/hardness_conversion_2c.htm
_________________________
Food for thought on suitable methods of heat treat for commercial
production lines and laboratories.
Steve
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Steve Laifman
Editor
http://www.TigersUnited.com
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