There was a day when countries defended themselves with magnificent
wooden warships, tall-masted and bristling with cannons. Impressive projections
of political power on the high seas, these ships succumbed to technology when
it occurred to nautical visionaries that smaller, more maneuverable ships clad
in iron plates might be less susceptible to fire (and much more difficult to
sink).
Iron-clad performance became legendary in the Civil War battle of Hampton
Roads where two such “ironclad” ships did battle for the first time. The CSS Virginia and the USS Monitor repeatedly
tried to ram one another while their shells bounced off each other’s armor. The
seminal battle attracted attention worldwide, effectively ending the long reign
of the wooden warship.
Is it any wonder the term ironclad
would forever define something very rigid or exacting; inflexible or
unbreakable?
Today the term has
bearing in mechanized welding procedures that clad
to reinforce or repair piping systems that are susceptible to physical or
corrosive damage.
Cladding now replaces
the old iron with numerous metals and alloys that contribute superior strength,
wear or corrosion resistance.
Sometimes referred to
as hard-cladding or hard-facing, the idea is to weld layers of more durable metal
over the surface, leaving the original metal structure intact. This is done
frequently in industries such as construction where the front edge of a
bulldozer blade or the teeth of excavator bucket have cladding metal welded on
to sacrificially wear. This can be done initially to ensure increased service life
or as a repair method to replace original metal lost to hard use.
Effectively, any orbital welding system, including Tri Tool’s AdaptARC®
Multi-process Welding System that can be configured to weld in a straight line
can perform cladding operations. Sometimes special fixturing or mounting tracks
need to be designed to permit the weld deposition on existing surfaces.
Cladding is not
limited to straight, linear welding, however. Successful cladding can be applied
on the OD surface of pipe or fitting or the inside bore, particularly when the
material flowing in the pipe is of a highly corrosive nature such as ground
water in Geo-thermal energy production facilities.
Multi-process automated welding systems have the distinct advantage
of being able to select the welding mode best suited for a specific cladding requirement.
This versatility means that GTAW, GMAW and FCAW can all be used for dependable
cladding with high performance deposition rates.
Cladding is often
performed to re-establish original material dimensions. This is extremely
important in applications where large bushings or packings have worn large
diameter shafts in power turbines. Wear has reduced the shaft diameter to the
extent that seals or bearings can not seat properly. This critical problem can
be the cause of major plant outages and often, replacements for original
turbine shafts were never produced or are not available.
In this situation,
the worn-away metal can be replaced by high-deposition weld techniques that
build up cladding layers beyond the original dimension. Next, the welding head
can be replaced by portable machine tools that
precisely cut the clad metal down, re-establishing the original surfaces.
This weld cladding followed
by in situ machining approach to power plant maintenance is extremely effective in
performing a crucial repair quickly and reliably, and without requiring the
removal and transportation (or replacement) of a remarkably expensive shaft.
As you can see, just
like when the world transitioned to layering iron plates to make warships more
durable, today’s cladding techniques provide a tough wearing, anti corrosion
layer to protect or repair important structures.
Contact Tri Tool and
we will provide an Ironclad Solution
for your most demanding industrial or commercial applications.