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different iron alloys (was Re: What is the best free software for creating & editing PDFs nowadays)

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Sam Plusnet <not@home.com> writes:
> On 31/08/2026 09:11, Bertel Lund Hansen wrote:
>> I question that. Wikipedia has an article about cast iron and
>> another one about steel. Though both kinds have iron plus
>> impurities, their properties are sufficiently different to earn
>> different names - and more important, different uses.
>> 
> Iron may 'suffer' from impurities, whilst steel contains carefully
> controlled 'impurities' which are selected to give it the preferred
> properties.

It’s quite a bit more confusing than that.

References to unqualified “iron” before the 19th century, and sometimes
thereafter, almost invariably refer to wrought iron.

Wrought iron (which is no longer manufactured commercially, not since
Thomas Walmley and Sons shut down the Aston Forge in Bolton in England
in 01973) overlaps with mild steel in composition, but has a different
macrostructure, with slag inclusions giving it a fibrous structure and
reducing its susceptibility to corrosion.

In the specific case of *cast* iron, “iron” *also* "contains carefully
controlled impurities which are selected to give it the preferred
properties".  In fact, the main impurity in both cases is carbon.  Cast
iron has quite a bit more of it (over 2%) than steel; low-carbon “mild”
grades of steel can have as little carbon as wrought iron does.  Roughly
speaking, the usual ferrous grades are something like this:

- 0–0.1% carbon: wrought iron
- 0.05–0.3% carbon: mild steel
- 0.3–2.1% carbon: carbon steel
- 2.1–4.5% carbon: cast iron
- 3.5–4.7% carbon: pig iron (rarely seen outside foundries)

Also, if you have 10.5% or more of chromium, it’s “stainless steel”,
even if it has no carbon.

Cast iron normally also contains silicon to improve its casting
properties.

From the perspective of anyone who has studied this stuff, the above is
a terrible oversimplification, since there are hundreds of grades of
steels, with dramatically different properties, and different pieces of
steel may even have the same composition but dramatically different
properties due to heat treatment.

This is almost certainly off-topic for alt.usage.english at this point,
but which of the still-active newsfroups would be best for it?

Kragen

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different iron alloys (was Re: What is the best free software for creating & editing PDFs nowadays) Kragen Javier Sitaker <kragen@canonical.org> - 2026-08-31 21:00 -0300
  Re: different iron alloys (was Re: What is the best free software for creating & editing PDFs nowadays) Peter Moylan <peter@pmoylan.org> - 2026-09-01 10:29 +1000
  Re: different iron alloys (was Re: What is the best free software for creating & editing PDFs nowadays) Bertel Lund Hansen <rundtosset@lundhansen.dk> - 2026-09-01 08:08 +0200
    active and healthy newsgroups in 02026 (was Re: different iron alloys) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-01 10:15 -0300

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