A
Agriculture
Agribusiness never had it so good. Because galvanized steel is prolonging
the life of farm structures and equipment everywhere and reducing maintenance
costs at the same time. Irrigation equipment. Animal pens. Green houses.
Buildings. You name it. Both family farmers and farm corporations know
galvanized steel facilities keep operating longer, with minimum maintenance.
B Bridges and Highways
When we drive, we drive through a world of galvanized steel: Guard rails,
signs, light poles,bridges, and tunnels: all use hot-dip galvanized steel,
and no wonder. Enduring the corrosive assaults of climate, weather, chemicals
and exhaust fumes, year after year, highway structures require the long-term
protection only galvanizing can provide.
C Construction
Every month thousands of tons of steel go
into general construction: commercial buildings, government buildings,
shopping centers, apartments, schools, and stadiums. And much of that
steel is protected against corrosion by hot-dip galvanizing. The long
life and low maintenance of galvanized steel railings, structurals, and
miscellaneous hardware represent a substantial return on investment.
D Distortion
Minimizing potential warpage and distortion is easily done in a project's
design stages by selecting steel of equal thicknesses for use in every
separate subassembly that is to be hot-dip galvanized, using symmetrical
designs whenever possible, and by avoiding the use of light-gage steel
(<1/16" / 1.6 mm). Some structures may benefit from the use of
temporary bracing to help maintain their shape and/or alignment.
E
Economy
Corrosion annually costs the U.S. economy 3.2 percent of the gross national
product, over $279 billion. Indirect costs to the public could raise
the percentage to as much as 6 percent. Some indirect costs of corrosion
are: lost productivity due to traffic delays, accidents caused by corroded
hand and guardrails, excessive use of nature's raw materials and energy
to replace corroded steel.*
F Fluxing
Steel is immersed in liquid flux (usually a zinc ammonium chloride solution)
to remove oxides and to prevent oxidation prior to dipping into the molten
zinc bath. In the dry galvanizing process, the item is separately dipped
in a liquid flux bath, removed, allowed to dry, and then galvanized. In
the wet galvanizing process, the flux floats atop the molten zinc and
the item passes through the flux immediately prior to galvanizing.*
H
History of Galvanizing
The recorded history of galvanizing goes back to 1742 when a French chemist
named P.J. Malouin, in a presentation to the French Royal Academy, described
a method of coating iron by dipping it in molten zinc.
In 1836, Stanilaus Tranquille Modeste Sorel, another French chemist, obtained
a patent for a means of coating iron with zinc, after first cleaning it
with 9% sulfuric acid and fluxing it with ammonium chloride. A British
patent for a similar process was granted in 1837. By 1850, the British
galvanizing industry was using 10,000 tons of zinc a year for the protection
of steel.
When the Brooklyn Bridge was built, over 14,500 miles of hot-dip galvanized
wire were used for its four main cables. Over 100 years later when the
bridge underwent massive rehabilitation, the hot-dip galvanized wire was
in excellent condition.
Hot-dip galvanized steel lasts longer today than it did 20 years ago.
Because of environmental laws, our air is cleaner and less contaminated
with corrosive emissions.*
K
Kettles
Galvanizer's kettles are set at temperatures ranging between 815 F and
850 F (435 C to 454 C). Galvanizers can hot-dip galvanize a piece of steel
that is larger than the kettle dimensions; it's called progressive dipping.*
South Atlantic Galvanizing's largest kettle, located in North Carolina
is 51’ long x 5’ wide x 10’ deep.
L
Life Cycle
Because of the long life of the hot-dip galvanized coating and its virtually
maintenance-free performance, galvanizing is consistently a better value
than paint over a structure's life. Galvanizing durability and lifetime
performance make it the logical choice when it is the lowest original
cost system.* 
M Marine Environments
Down to the sea again to paint that marina. And again. And yet again.
That's a sad and all to familiar verse where a structure must withstand
the corrosive power of salt water and sea air. And its out of tune with
modern scientific knowledge of corrosion in marine environments. Today,
designers and engineers know hot- dip galvanizing offers effective, proven
protection for steel in marine environments.
P Paint
When compared with paint systems, hot-dip galvanizing after fabrication
has comparable initial application costs and, almost always, lower life-cycle
costs. In fact, the lower life-cycle costs of a hot-dip galvanized project
make galvanizing the smart choice for today and tomorrow.*
R Resisting Abrasion
The three intermetallic layers that form during the galvanizing process
are all harder than the substrate steel and have excellent abrasion resistance.
*
S Service Life
The corrosion rate of zinc and how long it will provide protection is
a function of the coating thickness and the amount of corrosive elements
in the atmosphere. For example, in rural settings where there is
less automotive/truck exhaust and plant emissions, galvanized steel can
easily last for 100 - 150 years without maintenance. Industrial
and marine locations contain significantly more aggressive corrosion elements
such as chlorides and sulfides and galvanized steel may last for 50 - 100
years in those cases. The relationship between coating thickness
and atmospheric conditions is contained in a popular graph developed by
the AGA.
T Time
A galvanizer knows that a piece of steel should be immersed for a specific
amount of time in order for the metallurgical reaction between zinc and
iron to reach completion. The completion of the metallurgical reaction
is observed when bubbling of the molten zinc in the kettle stops.
At this point, the galvanizing is complete and the steel is removed from
the kettle to cool.*
U Uses
The complete list of the uses of galvanized steel is nearly too long to
list here. Structural steel (angles, channels, wide-flange beams, I-beams,
H-beams), grating, expanded metal, corrugated sheets, wire, cables, plate,
castings, tubing, pipe, bolts & nuts. The industries that utilized
hot-dip galvanized steel range from bridge & highway (reinforcing
steel for decks and column concrete, girders, stringers, light and signposts,
guardrail, fencing), water & wastewater treatment plants (walkway
grating/expanded metal, handrails) architectural (facades, exposed structural
steel, lentils), parking garages (reinforcing steel for concrete decks,
exposed structural steel columns and barriers), pulp & paper plants
(structural steel, walkways, handrail), OEMs (motor housings, electrical
cabinets, frames, heat exchanger coils), electrical utilities (transmission
towers, distribution poles, substations, wind turbine poles), communication
(cell towers), rail transportation (poles, switchgear, miscellaneous hardware),
chemical/petro-chemical (pipeline hardware, manufacturing buildings, storage
tanks, walkways), recreation (boat trailers, stadiums, arenas, racetracks),
and many more.*
V Vent holes
The primary reason for designing venting and drainage holes into a product's
design is to allow otherwise trapped air and gases to escape; the primary
reason for drain holes is to allow cleaning solutions and molten zinc
metal to flow entirely into, over, and throughout the part, and then back
into the tank or kettle.*
W Weight
As an average, the weight of the article will increase by about 3.5% due
to zinc picked up in the galvanizing process. However, that figure can
vary greatly based on numerous factors. The fabrication's shape, size,
and steel chemistry all play a major role, and other factors like the
black weight, the different types of steel that get welded together, and
the galvanizing bath chemistry can also have an effect.* X Xtreme temperatures
Constant exposure to temperatures below 390 degrees F (200 degrees C)
is a perfectly acceptable environment for hot-dip galvanized steel.
Good performance can also be obtained when hot-dip galvanized steel is
exposed to temperatures above 390 degrees F (200 degrees C) on an intermittent
basis.*
Z Zinc
As it is used in galvanizing, zinc is a healthy metal, completely recyclable.
The energy used to melt zinc is inversely related to the amount of zinc
recycled.*
*Source: American Galvanizers Association
South
Atlantic Galvanized Steel
South
Atlantic GalvanizingSouth
Atlantic Lintels
Member