Stainless Steel Chemical Composition

Long Products

AlloyUNS No.CarbonChromiumNickelManganeseSiliconSulfurPhosphorusMolybdenumOthers
301S301000.1516-186-8210.030.04
302S302000.1517-198-10210.030.04
303S303000.1517-198-1021.15 Min.0.20.6
303 Project 70+®S303000.1217-198-1021.15 Min.0.2
303SES303230.1217-198-1021.12/.17Se.15/35
304S304000.0818-208-12210.030.04
304 Project 70+®S304000.0818-208-10.5210.030.045
304LS304030.0318-208-12210.030.04
304L Project 70+®S304030.0318-208-12210.030.045
316S316000.0816-1810-14210.030.042.0-3.0
316 Project 70+®S316000.0816-1810-14210.030.0452.0-3.0
316LS316030.0316-1810-14210.030.042.0-3.0
316L Project 70+®S316030.0316-1810-14210.030.0452.0-3.0
321S321000.0817-199-12210.030.04Titanium Min. 5xC
410S410000.1511.5-13.5110.030.04
416S416000.1512-141.251.15 Min.0.060.6
416 Project 70+®S416000.1512-141.251.15 Min.0.06
420S42000.15 Min12-14110.030.04
430FS430200.1216-180.75110.030.04
440CS44004.95 - 1.216-18110.030.040.75
15-5S155000.0714-15.53.5-5.5110.030.04Copper 2.5/4.5; Cb and Ta .15/.45
17-4S174000.0715.5-17.53-5110.030.04Copper 5.0;
Cb and Ta .45
AlloyUNS No.CarbonChromiumNickelManganeseSiliconSulfurPhosphorusMolybdenumOthers
301S301000.1516-186-8210.030.04
302S302000.1517-198-10210.030.04
303S303000.1517-198-1021.15 Min.0.20.6
303 Project 70+®S303000.1217-198-1021.15 Min.0.2
303SES303230.1217-198-1021.12/.17Se.15/35
304S304000.0818-208-12210.030.04
304 Project 70+®S304000.0818-208-10.5210.030.045
304LS304030.0318-208-12210.030.04
304L Project 70+®S304030.0318-208-12210.030.045
316S316000.0816-1810-14210.030.042.0-3.0
316 Project 70+®S316000.0816-1810-14210.030.0452.0-3.0
316LS316030.0316-1810-14210.030.042.0-3.0
316L Project 70+®S316030.0316-1810-14210.030.0452.0-3.0
321S321000.0817-199-12210.030.04Titanium Min. 5xC
410S410000.1511.5-13.5110.030.04
416S416000.1512-141.251.15 Min.0.060.6
416 Project 70+®S416000.1512-141.251.15 Min.0.06
420S42000.15 Min12-14110.030.04
430FS430200.1216-180.75110.030.04
440CS44004.95 - 1.216-18110.030.040.75
15-5S155000.0714-15.53.5-5.5110.030.04Copper 2.5/4.5; Cb and Ta .15/.45
17-4S174000.0715.5-17.53-5110.030.04Copper 5.0;
Cb and Ta .45

Alloying Elements

Chromium — Most important element of stainless steel. An addition of 10% chromium will form an oxide film (passive surface film) which renders the steel corrosion resistant. Chromium also increases resistance to scaling.

Nickel — Second most important element. It increases ductility, corrosion resistance, scaling resistance, and high-temperature strength.

Silicon — Primarily increases resistance to scaling.

Manganese — Improves hot-working properties.

Molybdenum — Increases corrosion and high-temperature strength.

Sulfur-Phosphorus-Selenium — Increases machinability.

Titanium or Columbium-Tantalum — Stabilizes carbon and prevents chromium-carbide precipitation and subsequent intergranular corrosion.