IQS Newsroom Articles on Stainless Steel
About Stainless Steel and Stainless Steel Products
Including: Stainless
Steel Sheets, Stainless
Steel Suppliers, Stainless
Steel Plate, Stainless
Steel Rods & Stainless
Steel Wires.
Stainless steel, which is also known as "corrosion
resistant steel" and "chromium steel", is steel which
is alloyed with a minimum of 10% chromium. Regular steel often contains
smaller amounts of chromium to enhance properties of strength and hardness,
but steel alloyed with more than 10% chromium develops a "passivation" layer
of chromium oxide on its outer surfaces, effectively coating the steel
and protecting it from the harmful oxidation that occurs between exposed
iron and oxygen molecules in the air. This protecting layer of chromium
oxide easily reforms when scratched, making stainless steel an excellent
durable solution even for high-use applications such as machine blades
and cutlery. Just like other alloyed metals, stainless steel is processed
by mills and stainless steel suppliers into stock stainless
steel plates, stainless
steel rods, stainless
steel sheets, stainless
steel wire and stainless
steel tubing. Stainless
suppliers and steel
service centers often specialize in heat-treating, alloying, hot-rolling
and cold-rolling plates and sheets to enhance properties of hardness
and strength.
Regular steel is iron ore which has undergone a high-heat refining process
called "smelting", then has been further refined and alloyed
with small amounts of carbon, manganese, chromium, vanadium or tungsten.
Stainless steel is milled from this stage by increasing the amount of
chromium and adding other elements to the molten steel. Carbon, nickel,
molybdenum, silicone and trace amounts of other elements are alloyed
to stainless steel in various amounts to enhance steel's various
properties. Nickel alloyed with stainless steel causes it to be non-magnetic
and less brittle; carbon increases properties of hardness and strength;
molybdenum increases corrosion resistance, and aluminum and titanium
are sometimes used as "filler" alloys to decrease cost or
weight.
There are three main types of stainless steel which combine nickel, carbon
and molybdenum in different ratios to achieve different qualities. Austenitic
stainless steel combines the largest ratios of chromium, nickel and molybdenum
and accounts for about 70% of fabricated stainless steel, with the most
common grade being 18/10 stainless, an 18% chromium 10% nickel alloy
which is very hard, durable and resistant to corrosion. Flatware is typically
made of 18/10 stainless. Austenitic steel grades have a great strength-to-weight
advantage over other materials; they also provide impact resistance and
toughness in extreme temperatures, making them suitable for cryogenic
applications. Ferritic stainless steel has very low nickel content, higher
carbon content and is highly corrosion resistant but less strong and
durable than austenitic stainless. Martensitic stainless steel contains
higher levels of carbon and often molybdenum, making it extremely strong
and durable with lower corrosion resistance. Some grades of stainless steel can transform from martensite to austenitic under heat treatment or with the addition of chromium; maraging steel, a specialty low-carbon ultra-high strength steel alloy, is made martensite when a portion of the alloy's nickel content is substituted by chromium to enhance corrosion resistance and hardness.
Since the invention of stainless steel in the early 1900's, many
architectural achievements have been made which were formerly impossible,
and the exponential progress made in aerospace, marine, electronics and
many other industries are due at least in part to stainless steel's
corrosion resistance and strength. Structures in the U.S. like the Chrysler
Building, St. Louis' Gateway Arch and the Dover Building sculpture
in Syracuse, New York attest to the lasting structural and aesthetic
integrity of stainless steel. Stainless steel also poses an economic
advantage to industrial manufacturers and architects, since it is 100%
recyclable, and its key elements iron ore, nickel, chromium and carbon
are common enough to keep production costs down. Stainless steel is fully
machinable, being just as easily cut, welded, formed, machined and fabricated
as other steels. Because steel is easily alloyed, another one of stainless
steel's attributes is its versatility; with more than 80 different
types of stainless steel alloys, manufacturers are sure to find an alloy
with properties that fit their specific application requirements.
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Stainless Steel and Stainless
Steel Product Manufacturers Image Provided by Source
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Types of Stainless Steel
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is an austenitic alloy that has sulfur and/or selenium added to create
a free-machining stainless steel. 303 stainless steels take less time
to machine, resulting in longer lasting machine tool bits and lower
production cost.
-
is an austenitic alloy that is easily formed and welded but is not a
free-machining material. 304 stainless steel is commonly used for sheet
metal products that are not subject to harsh environments.
-
is one of the most frequently used austenitic alloys in the stainless
steel family. 304L stainless steel is utilized when parts are to be
welded, especially if the weld might come in contact with chlorinated
water.
-
is an austenitic alloy that is very corrosion resistant and has a higher
nickel content. 305 stainless has a decreased tendency to work-harden
during the cold heading process.
-
is a non-magnetic material that contains molybdenum and a higher nickel
content. 316 stainless steel, an austenitic alloy, is very corrosion
resistant but is subject to attack if exposed to high levels of chlorine
for a long period of time.
-
is a highly corrosion resistant austenitic alloy that is second only
to 304 stainless steel in importance. 316L stainless steel is commonly
used in heavy gauge welded components, as it offers higher creep, stress-to-rupture
and tensile strength at elevated temperatures.
-
has a very high nickel content and is very corrosion resistant to chlorides.
384 stainless steel, an austenitic alloy, cold heads well.
- alloys are comprised of chromium and nickel and are used
in mild, harsh and corrosive environments. Austenitic stainless steel
alloys account for about 70% of the stainless steel family.
- ,
along with the elements iron, chromium and nickel, contain molybdenum,
nitrogen, copper and very little carbon. Duplex stainless steel has
double the strength of austenitic stainless steel and better corrosion
resistance than martensitic stainless steel.
- consists of only iron and chromium. Ferrite stainless
steel is magnetic, cannot be hardened and is used mainly in decorative
trim and mufflers for vehicles.
- have low chromium levels and
high carbon content but do not contain nickel. Martensitic stainless
steel is a magnetic material that has reduced corrosion resistance but
can be heat-treated to provide high strength and toughness characteristics.
- are chromium-nickel grades that can be strengthened
and hardened by adding such elements as copper and aluminum in an aging
treatment at elevated temperatures.
-
are solid pieces of various grade stainless steels that are rolled from
billets. Stainless steel bars can be hot or cold finished and formed
into rounds, squares, hexagons, octagons or flats.
-
are tubes that are used to transport gases or liquids. Stainless steel
pipes are much longer lasting than similar products consisting of other
metals, because of the corrosion resistance of the material.
-
have a width over eight inches and a thickness from one quarter of an
inch to over a foot.
- are long cylinder-shaped objects made of stainless steel.
-
are large, thin slices of stainless steel. Usually rectangular or square
shaped, stainless steel sheets offer the flexibility of being custom
fabricated or molded.
- provide the rods, sheets, and plates used in the assembly of many products.
-
ranges in size from less than .01 inches to more than six inches in
diameter.
-
offer good strength-to-weight ratios, as well as rustproof performance.
Common diameters of stainless steel wires range anywhere from .01 inches
to 1-1/16 inches.
Common Terms Related to Stainless Steel
-
A heat-treating process used on martensitic stainless steels to harden
them. The material is heated above its critical temperature, held at that
temperature to ensure uniform temperature and then quenched in air or
oil to quickly cool it.
- A solid solution of
two or more metals. All forms of stainless steel are alloys.
- A process by which
a cold-rolled steel coil is heated to a designated temperature and then
cooled. The annealing process makes the coil easier to bend and form.
-
A process with a short operation time and low temperatures that is used
to reduce the carbon content of stainless steel during the refinement
process.
- A short bar of metal.
- A piece of sheet stainless
steel that has the specified outer dimensions of a part but has not yet
been stamped by the end user. Blanks decrease the cost of labor and transportation
for the stainless steel processor.
- A cylinder lined
with heat resistant bricks that steel mills use to smelt iron from ore.
The name originates from the blast of hot air that is forced up through
the ore.
- A semi-finished form
of stainless steel that typically has a cross-section greater than 36
sq. inches. A bloom will be further processed into mill products.
- A ridge on the edge of
strip stainless steel that is caused by cutting operations, including
blanking, trimming, shearing or slitting.
- An element added
to stainless steel, resulting in a corrosion resistant alloy.
- Also called "cold
working" it is any kind of mechanical operation performed at room
temperature that causes permanent deformation. Cold forming, which includes
bending, rolling and drawing, increases the hardness and strength of stainless
steel.
- A time-saving
process of pouring stainless steel directly from the furnace into a billet,
bloom or slab. Continuous casting eliminates the need for large, expensive
mills.
- The ability of steel
to go through permanent changes of shape without fracturing.
- Coated with zinc.
Galvanizing provides more corrosion resistance and is used on auto underbody
parts, storage tanks, garbage cans, etc.
- A number or symbol given
to different varieties of steel. Different grade steels have varying characteristics
and compositions.
- Method used to
wind narrow strip steel over a wider roll. The oscillating process is
similar to winding fishing line over a spool.
- A
steel bar used to further strengthen concrete. Rebars are vital for highway
reinforcement as well as building construction.