Stainless Steel Information Knowledge alloys 316 304

STAINLESS STEEL INFO

The following is a discussion of the various types of stainless steel. For other terms and their definitions you will encounter when dealing with stainless steel click here.

18-8: 300 series stainless steel having approximately (not exactly) 18% chromium and 8% nickel. The term "18-8" is used interchangeably to characterize fittings made of 302, 302HQ, 303, 304, 305, 384, XM7, and other variables of these grades with close chemical compositions. There is little overall difference in corrosion resistance among the "18-8" types, but slight differences in chemical composition do make certain grades more resistant than others do against particular chemicals or atmospheres. "18-8" has superior corrosion resistance to 400 series stainless, is generally nonmagnetic, and is hardenable only by cold working.

304: The basic alloy. Type 304 (18-8) is an austenitic steel possessing a minimum of 18% chromium and 8% nickel, combined with a maximum of 0.08% carbon. It is a nonmagnetic steel which cannot be hardened by heat treatment, but instead. must be cold worked to obtain higher tensile strengths.
The 18% minimum chromium content provides corrosion and oxidation resistance. The alloy's metallurgical characteristics are established primarily by the nickel content (8% mm.), which also extends resistance to corrosion caused by reducing chemicals. Carbon, a necessity of mixed benefit, is held at a level (0.08% max.) that is satisfactory for most service applications.
The stainless alloy resists most oxidizing acids and can withstand all ordinary rusting. HOWEVER, IT WILL TARNISH. It is immune to foodstuffs, sterilizing solutions, most of the organic chemicals and dyestuffs, and a wide variety of inorganic chemicals. Type 304, or one of its modifications, is the material specified more than 50% of the time whenever a stainless steel is used.
Because of its ability to withstand the corrosive action of various acids found in fruits, meats, milk, and vegetables, Type 304 is used for sinks, tabletops, coffee urns, stoves, refrigerators, milk and cream dispensers, and steam tables. It is also used in numerous other utensils such as cooking appliances, pots, pans, and flatware.
Type 304 is especially suited for all types of dairy equipment - milking machines, containers, homogenizers, sterilizers, and storage and hauling tanks, including piping, valves, milk trucks and railroad cars. This 18-8 alloy is equally serviceable in the brewing industry where it is used in pipelines, yeast pans, fermentation vats, storage and railway cars, etc. The citrus and fruit juice industry also uses Type 304 for all their handling, crushing, preparation, storage and hauling equipment.
In those food processing applications such as in mills, bakeries, and slaughter and packing houses, all metal equipment exposed to animal and vegetable oils, fats, and acids is manufactured from Type 304.
Type 304 is also used for the dye tanks, pipelines buckets, dippers, etc. that come in contact with the lormic, acetic, and other organic acids used in the dyeing industry.
In the marine environment, because of it slightly higher strength and wear resistance than type 316 it is also used for nuts, bolts, screws, and other fasteners. It is also used for springs, cogs, and other components where both wear and corrosion resistance is needed.


Type Analysis of Stainless Type 304
Carbon 0.08% max. Silicon 1.00% max.
Manganese 2.00% max. Chromium 18.00-20.00%
Phosphorus 0.045% max. Nickel 8.00-10.50%
Sulfur 0.030% max.


316: For severe environments. Of course, there are many industrial processes that require a higher level of resistance to corrosion than Type 304 can offer. For these applications, Type 316 is the answer.
Type 316 is also austenitic, non-magnetic, and thermally nonhardenable stainless steel like Type 304. The carbon content is held to 0.08% maximum, while the nickel content is increased slightly. What distinguishes Type 316 from Type 304 is the addition of molybdenum up to a maximum of 3%.
Molybdenum increases the corrosion resistance of this chromium-nickel alloy to withstand attack by many industrial chemicals and solvents, and, in particular, inhibits pitting caused by chlorides. As such, molybdenum is one of the single most useful alloying additives in the fight against corrosion.
By virtue of the molybdenum addition, Type 316 can withstand corrosive attack by sodium and calcium brines, hypochlorite solutions, phosphoric acid; and the sulfite liquors and sulfurous acids used in the paper pulp industry. This alloy, therefore, is specified for industrial equipment that handles the corrosive process chemicals used to produce inks, rayons, photographic chemicals, paper, textiles, bleaches, and rubber. Type 316 is also used extensively for surgical implants within the hostile environment of the body.
Type 316 is the main stainless used in the marine environment, with the exception of fasteners and other items where strength and wear resistance are needed, then Type 304 (18-8) is typically used.

Type Analysis of Stainless Type 316:
Carbon 0.08% max. Silicon 1.00% max.
Manganese 2.00% max. Chromium 16.00-18.00%
Phosphorus 0.045% max. Nickel 10.00-14.00%
Sulfur 0.030% max. Molybdenum 2.00-3.00%

Stainless Steel Material Information

Stainless Steel, unlike carbon steel, is corrosion resistant. It contains chromium which, when exposed to oxygen, creates an invisible protective film. Stainless steel types are classified into three different groups based on their ability to be hardened. Austenitic stainless steels, which can be hardened by cold working, meet a wide range of design criteria. They are essentially non-magnetic, although they may become slightly magnetic due to cold working. Martensitic stainless steels are straight-chromium types that can be hardened by heat treatment. They are magnetic. Ferritic stainless steels, like Martensitic stainless steels, are straight-chromium types and they are magnetic. Ferric stainless steel, however, cannot be hardened by heat treating and only moderately hardened by cold working.

Commonly Perforated
Stainless Steel Types

304 (Austenitic)
One of the most widely used general-purpose stainless steels. It possesses an excellent combination of strength, corrosion resistance and fabricates well. To reduce carbide precipitation when welding, use 304L for its lower-carbon content.

316 (Austenitic)
Superior corrosion resistance compared to other 300 series alloys when used in used harsh corrosive environments (ex. sea water, chemicals, etc.). To reduce carbide precipitation when welding, use 316L for its lower-carbon content.
321 (Austenitic)
Titanium stabilized stainless steel to prevent intergranular formation of chromium carbide. It exhibits strength characteristics superior to those of 304 stainless, thus making it best suited for parts which cannot be subsequently annealed.

410 (Martensitic)
The lowest alloy content of the three general-purpose types. It is a heat-treatable chromium type used for highly stressed parts needing the combination of strength and corrosion resistance.

409 (Ferritic)
The lowest chromium content of the stainless steels, 409 combines good elevated temperature corrosion resistance with medium strength, good formability, and overall cost.

430 (Ferritic)
A general-purpose non-heat-treatable chromium type used for highly polished trim applications in mild atmospheres. Its strengths are in ductility, formability, good corrosion and oxidation resistance, thermal conductivity and finish quality.

Embossed Decorative Stainless Steel Sheets

We are a professionally managed company with a plant using imported German Machinery for manufacturing sinks and having entire process of manufacturing from start to finish all under one roof in order to maintain its quality.
Having contacts with reputed Builders, Interior designers, Architects, etc. we also undertake fabrication works from them such as Kitchen Tables, Ventilator hoods, Garbage bins, Food Counters, False Ceiling Panels, Building Entrances, Safety Lockers, etc.
We are interested in selling sheets of decorative finish. We would be obliged if you would send us your detailed requirment, and various other terms and conditions. Visit us at www.kanoigroup.com

Providing stainless steel doors for residential, light commercial, commercial use.

DECORATIVE DOORS IN STAINLESS STEEL
Advertorial for Construction Specifier, December 2004


When considering stainless steel doors, most architects think of specifications that are highly performance-driven, typically demanding corrosion-resistance or durability. Recently, though, there has been a trend toward more decorative applications for stainless, sometimes in places where it might least be expected.

What's driving the use of decorative stainless is the huge variety of finishes and patterns. From subtle looks like bead-blasted to custom-developed, multi-colored patterns that are etched electromagnetically, the options are truly endless. While you might expect a more decorative look in an office building or a restaurant, Next Door Company has recently seen more decorative doors being used in locations such as classroom entrances, subway stations and even a bridge control house. The doors can add a touch of style to an otherwise unremarkable setting.

Next Door has long been creating custom doors and has led the industry in decorative applications. They can engineer almost any door design in any type of decorative stainless finish. Most customers will find more than enough selection from the standard finishes; however, custom patterns are no problem, thanks to Next Door's partnership with Novel Architectural Products, the leader in custom etched finishes. They can reproduce a customer's own pattern in stainless and even make panels and column covers to match.

Next Door is able to work with customers to create a total decorative look. They have partnerships with leading-edge designer hardware companies that can complete a design look with unique pulls or levers in stainless. They can also create custom pulls per the customer's design. For glass doors, Next Door partners with leading manufacturers of decorative glass from around the world.

Decorative Steel Manufacturing Process

The process of PVD coating ( Physical Vapor Deposition of titanium or zirconium ) is used to manufacture Ornamental and Decorative Steel. It provides a colored film over the stainless steel substrate in a vacuum chamber. The film also has fine conductibility and self-lubricating capability with rich colors available from light to dark such as brass, gold, rose-gold, copper, smoke-gray, dark-gray and dark, over natural polished stainless steel finishes. The PVD coating process can be treated on stainless steel substrate of common sizes eg. 4'X8' (1219X2438mm ), 4'X10' (1219X3048mm) or other specified sizes. The colored PVD coated ( Ti/Zr-plated ) sheets is widely used in many applications such as elevator cabin, doors, frames, columns and wall panel, etc. The PVD coating process provides much better results compared to polishing. In Polishing, the material is polished with some chemical, etc to give it the required finish like the mirror finish, hair line finish, etc. The polishing process is much more complex then PVD coating as getting a uniform polish through out is a though task.