On the physical conditions involved in the construction of artillery

[subdjoe]

On the physical conditions involved in the construction of artillery: with an investigation of the relative and absolute values of the materials principally employed, and of some hitherto unexplained causes of the destruction of cannon in service (1856)

I suspect that this one has been posted before.  But, hey, it has some good light reading:

22.—Molecular Constitution of Wrought-Iron^ and the Law of Direction of its
Crystals or Fibre.
193. When wrought-iron in any ofthe usual forms of its manufacture is fractured,
its molecular structure presents itself, more or less distinctly pronounced,
in one or other of three forms :
—
1°. Its mass consists ofminute crystals ofnearly uniform size, whose facets
present themselves at all possible angles, like that of refined
sugar.
This " saccharoid" structure usually belongs to the most highly
refined iron, and often to hard steely irons, such as those of Sweden.
The larger bars of Low Moor iron present, perhaps, the finest
examples of this structure.
2°. The surface of fracture consists of large, sometimes very large, lamellar
spangles or plates, the facets of crystalline cleavage, whose
directions tend to general coincidence with the surface of fracture.
The number, size, and direction of these facets vary in the
same mass with the direction of fracture. This is the structure
of all large and heavy forgings, or very large rolled bars, in which
the planes of crystallization tend towards a general perpendicularity
to the surfaces of external contour. This and the former
structure are often found irregularly united in the same surface
of fracture in ill-manufactured iron, and, united with the succeeding,
it is the usual one presented by small common bar-iron.
3°. The fracture (hard to produce, owing to the greater flexibility of the
iron than in either of the preceding cases) when effected, presents
long, parallel fibre, or bacillary crystals, running in the
direction of the longest dimension of the bar. This is the structure
of the best and toughest iron, such as that for making chains and
rivets, good boiler-plates, &c. It is found partially combined
with the 1st and 2nd in some inferior irons.
194. We found in cast-iron that the law of arrangement of its crystals is to

[Cat Whisperer]

I would love to see photomicrographs of the crystaline structure of the various irons and steels.

[keith44]

+1 what CW said

[subdjoe]

I wonder if in the past few decades Watervlite has taken any of those.

[dominick]

Interesting read, Thanks for posting.    I see why Krupp steel was much sought after.  Page n109, table VII.

[subdjoe]

Interesting read, Thanks for posting.    I see why Krupp steel was much sought after.  Page n109, table VII.

My pleasure, sir.

[Cannoneer]

FYI - This is the same Robert Mallet that designed the famous "Mallet's Mortar."

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