New-York tribune., 1912-03-10
Continued from first page.

or change Of volume, and the manner in
which this shrinkage is controlled has
much to do with the soundness Of the in
got AS soon as the liquid steel comes In
contact with the comparatively cold walls
Of the iron mould the steel solidihes in a
thin layer adjacent to the bottom and
sides Of the mould, thus forming steel
bottle or vessel containing the rest OF It's
own substance in molten state. This
happens before the whole mass OF steel
has shrunk to it's ultimate size when
frozen" The subsequent shrinkage OF
the fluid steel takes place progressively
inward in succeeding films adhering to
the flask first formed by the chill Of the
surrounding mould walls
This progressive freezing OF the coohng
steel leads TO the formation Of cavity
more or less tapering. reaching downward
into the body of the ingot. Sometimes tfis
shrlnkage cavity is a single inverted conical
hole. and AZ other times the upper recess is
followed by a succession of holes EXTENDING
deeper and deeper into the ingot. This tor
nation Is technically termed pipe, anu
as a rule the surfaces Of the pipe are
coated with an oxide which makes II Ut
,erly impossible TO weld together the "aii'
Of these cavities by rolling or compression
The line or streak OF oxide which remains
stubborniy is. in fact. fracture which
will spread under blows or bending stresses
until an open break occurs. NO part VI
piped ingOt should be worked into IAN
which is to support fast and heavy traiilc.
In addition to the defect of pipe. there IS
another disease to which the steel ingot Is
heir II the metal be poured at too nlgh
temperature and is overlong in reaching the
solid state. This disease Is called "segrega-
uon." because the alloys are not evenly
distributed throughout the whole BODY OF
The ngot. the percentage being highest III
The neighborhood Of that part OF the 'ngot
which freezes" last. When rolled into rails
steel OF this sort is not homogeneous from
end TO end nor from head TO foot or the
rack. Therefore, It cannot resist me
sresses 10 which IL is subjected, one part
0i The rail being different in its physical
qualities from the other parts. Apart from
'nis. the crystals OF the "segregate' are
harder and generally bigger thas those or
'he rest OF the ingot and under the nam
mer blows Of passing trains these harder
crystals attack and split apart the under
Ving hbres until a fracture takes place
ana. perhaps derailed train follows.
After the rail ingot has been cast the
mould is lifted or stripped from it, and the
hgot still red hot outwardly and probably
molten In it's upper and central parts, II
fut IN heating furnace called a soaking
pii' where It remains for some time. AT
mus stage the ingot must be kept upright,
es' us fluid contents flow like that Of a
party filled bottle and cause the bubble
VI shrinkage cavity to run deeper into the
mass These tng0ts are about five feet
"ign. Slightly tapering. and something like
sh'een inches square at the bottom.
;" men they are taken out OF the soaking
Ply they are passed through powerful oils
"'ne umes, each pass lengthening the mass
"nhe contracting its cross section After
ese nine passes, the ingots are called
"'ooms," and are about eight inches
'9uaFe IN cross section
nese operations have chilled the steel
'p me billet, or bloom. Is generally re-
A'ed before further work is done upon IL.
foon as II Is again at the proper tenn
'a'ufe II Is subjected 10 twelve or thIr-
~" more passes. which press the metal
~" 'he finished form, but before The bloom
WI through these passes the Top end
me billet is cut Off more Of less for the