| TYPES |
|
| 4 Major Types of Stainless Steel |
Description |
Common Uses |
| Austenitic |
most widely used, 7% Nickel Content, Flexible, not hardenable by heat treating |
houseware products, industrial piping and vessels, constructional structures, architectural facades |
| Ferritic |
better corrosion resistance than mild steel, similar properties to mild steel |
washing machines, boilers, indoor architecture |
| Martensitic |
very strong steel, ~13% Chromium, Duplex: higher resistance to chloride than austenitic, contains about 22-25% Chrome and 5% Nickel with Moly and Nitrogen. |
knives and turbine blades, Duplex: chemical plants and piping applications |
| Precipitation Hardening |
Chrome-Nickel Stainless, contain alloying additions like: aluminum, copper or titanium, allows for steels to be hardened by a solution of aging treatment. |
can be either austenitic or martensitic in ages condition, commonly used in aerospace and energy industries |
| Subtypes |
Major Type |
Description |
Common Uses |
| 303 |
Austenitic |
most machinable of austenitic ss grades, added sulfur to enhance machinability, resistant to atmospheric corrosion, food products, sterilization solutions, organic and inorganic chemicals |
shafts, valve bodies, valve trim and food industry applications |
| 304 |
Austenitic |
most common stainless, low carbon austenitic alloy, contains max .03% of carbon, minimizes carbide precipitation during welding |
welding, shafts, valve bodies, valve trim and food industry applications |
| 310 |
Austenitic |
superb high temperature properties, good ductility and weldability, resists oxidation in continuous service at a temp up to 1150ËšC without the presence of sulfur gases, can be used for intermittent service at temperature 1040ËšC |
molten salt, sulfur bearing gas, heat exchanger and recuperator tubing |
| 316 |
Austenitic |
second most common ss, added moly to prevent specific forms of corrosion, carbon is kept at .03% max to show minimized carbide precipitation, decreased sulfur, resistant to chloride corrosion |
electro-polishing, welding, marine applications, textile industry, food industry, watches, pharmaceutical equipment, valve bodies, bleaching and dying equipment |
| 317 |
Austenitic |
molybdenum-bearing austenitic chrome nickel, higher alloy content than 316 ss |
developed to resist the attack of sulfurous acid compounds |
| 321 |
Austenitic |
titanium bearing stainless, stabilized against carbide precipitation, combines with titanium in higher temperatures to form harmless titanium carbide, chrome maintains full corrosion resistance, titanium added at least 5x carbon plus nitrogen contents |
aircraft exhaust stacks, manifolds, chemical processing equipment, welding, jet engine parts |
| 347 |
Austenitic |
columbium/tantalum stabilized austenitic ss, good intergranular-corrosion, resistant to atmospheric conditions |
aircraft exhausts, expansion joints, high chemical processing, should be considered for application in intermittent heating between 800ËšF and 1650ËšF |
| 410 |
Martensitic |
hardenable martensitic alloy, good corrosion resistance, designed for high stress parts that need high ductility and corrosion resistance |
for working temps up to 1200ËšF, blades, buckets, steam turbines, turbine wheels, valves, aircraft parts, pumps, and pump shafts |
| 416 |
Martensitic |
highest machinability of any ss, made up of ~85% of a free-machining carbon steel, added sulfur to form manganese sulfide inclusions, less corrosion resistance than 410 |
welding, used in hardened/unhardened and highly tempered conditions because of low cost and ready machinability |
| 630 |
Precipitation Hardening |
Chromium-copper precipitation hardening stainless steel, high strength is maintained to approx. 316ËšC |
used for applications requiring high strength and a moderate level of corrosion resistance |
| 17-4 PH |
Precipitation Hardening |
precipitation hardening martensitic ss, with Cu and Nb/Co additions, high strength, hardness (in temps up to 572ËšF/300ËšC) , and adequate corrosion resistance |
aircraft and aerospace materials, fasteners, base plates, oil and petroleum refining equipment |
| 15-5 PH |
Precipitation Hardening |
martensitic precipitation hardened steel, offers high strength, excellent corrosion resistance, similar properties to 17-4 ph., more chemically balanced |
valve parts, paper mills, aircraft, power generation chemical processing, nuclear and space craft |
| 904L |
Austenitic |
non-stabilized low carbon high alloy austenitic ss, added copper for improved resistance, highly resistant to chloride attack, non-magnetic in all conditions, excellent weldability and formability |
used less due to cheaper substitute duplex stainless steel 2205 (S31803 or S32205) |
| 2205 |
Austenitic and Ferritic |
Duplex 2205, has microstructure that contains both austenitic and ferritic phases, good strength and corrosion resistance, twice the strength of typical austenitic stainless |
oil, pump and pump parts, valves, chemical and paper manufacturing |
| 2507 |
Austenitic and Ferritic |
Super Duplex 2507®; similar to UNS S31803 Duplex; longer lifespan, higher corrosion resistance; composed of: 24-26% of chromium, 6-8% nickel, 3% molybdenum, 1.2% manganese; more cost effective than high nickel alloys, high level of thermal conductivity |
oil and gas, chemical processing, desalination equipment, paper mill equipment, hydraulic and instrumentation products |
| Alloy 20 |
Austenitic |
super-austenitic stainless alloy, max corrosion resistance to sulfuric acid and other aggressive environments, nickel-iron-chromium based alloy with additions of copper and molybdenum |
pharmaceuticals, food, explosives, chemical processing, petroleum refinement |
| Nickel 200 |
- |
essentially pure nickel, good corrosion resistance, ferromagnetic, low electrical resistivity |
food handling equipment, caustic solution, for devices requiring magnetic actuated parts |
| Nickel 201 |
- |
low carbon modification of Nickel 200, preferred over Nickel 200 in temps above 600ËšF (315ËšF) |
for electronic industry at temps up to 1200ËšF (649ËšC) |
| Alloys |
Alloy Type |
Description |
Common Uses |
| Alloy 400 |
Monel, nickel/copper alloy |
machinable, easily fabricated, excellent strength, corrosion resistance, ductility, and weldability |
areas with salt water and brackish water, not susceptible to stress corrosion cracking |
| Alloy 600 |
Inconel, nickel/chrome/iron alloy |
acid resistant, high strength & good workability under various temperatures, resistance to corrosion and heat |
jet engines, super heaters, food processing, steam generators |
| Alloy 625 |
UNS N06625, nickel-chromium-molybdenum alloy |
high strength in temps up to 1500ËšF, oxidation resistance up to 1800ËšF, good corrosion resistance |
aerospace and marine engineering, chemical processing, pollution-control equipment, nuclear reactors |
| Alloy 800 |
Incoloy, nickel-iron/chrome alloy + copper and moly |
general corrosion resistance, pitting and crevice corrosion in chemicals containing chlorides, sulfuric, nitric, and phosphoric acids |
tanks, piping, heat exchangers, pumps, valves |
| Alloy 825 |
titanium stabilized austenitic nickel/iron/chrome alloy + copper and moly |
resistance to oxidizing and non-oxidizing hot acids, resistant to pitting and crevice corrosion |
salt-water cooled heat exchangers, offshore piping tube systems, evaporators, scrubbers |
| Alloy C-276 |
Hastelloy, nickel-molly-chrome alloy + tungsten |
corrosion resistant, resistant to pitting and crevice corrosion, resists stress corrosion cracking, oxidation resistant up to 1900ËšF |
tanks, piping, heat exchangers, pumps, valves |
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