Super-Austenitic Stainless Steel
Austenitic | Martensitic | Ferritic | Duplex | Super Duplex | Superaustenitic | Superferritic | Precipitation Hardening
Superaustenitic stainless steel have the same structure as the common austenitic alloys, but they have enhanced levels of elements such as chromium, nickel, molybdenum, copper, and nitrogen, which give them superior strength and corrosion resistance.
Super-austenitic stainless steel alloys are characterized by their high nickel and molybdenum contents plus nitrogen. The most common of the alloys are 904L, AL-6XN, 254 SMO, 25-6MO and 1925 hMO.Super-austenitic metal designed to resist crevice corrosion, pitting, chloride-induced corrosion, and stress corrosion cracking. It can also withstand alkaline and salt solutions, protecting against metallic contami- nation of product and preventing rapid degradation of the fluid transfer system
These alloys have a face-centered cubic crystal structure similar to other austenitic stainless steel and are non-magnetic and their magnetic permeability remains low even after severe cold forming. The nitrogen addition provides the alloy with improved resistance to pitting and crevice corrosion, a greater resistance to localized corrosion in oxidizing chlorides and reducing solutions plus higher strength. Nitrogen also helps to significantly reduce the potential formation of harmful secondary phases during welding.
Superaustenitic Stainless Steel Mechanical Properties and Physical Properties
Alloy (UNS) | End Use | Composition nominal wt% | Standard | Density lb/in3 (g/cm3) | Tensile Strength ksi. (MPa) | 0.2% Yield Strength ksi. (MPa) | Elong ation % | Hardness |
N08020 | Flue gas scrubbers, Sulphuric acid tanks and racks, Process piping, Heat exchanger, Manufacture of solvents/explosives /plastics/synthetic fibers/organic chemicals /pharmaceuticals | C 0.07 max, Mn 2.0 max, P 0.045 max, S 0.035 max, Si 1.0 max, Cr 19.0-21.0, Ni 32.0-38.0, Mo 2.0-3.0, Cu 3.0-4.0, Cb+Ta (8xC)min-1.0 max, Fe balance | ASTM B463 ASME SB-463 | 0.292 (8.09) | 80 min (550 min) | 35 min (240 min) | 30 min | 95 Rockwell B max |
S34565 | Desalination, seawater piping, offshore oil production, pollution control (FGD) | C 0.03 max, Mn 5.0-7.0, P 0.03 max, S 0.01 max, Si 1.0 max, Cr 23.0-25.0, Ni 16.0-18.0, Mo 4.0-5.0, N 0.4-0.6, Cb 0.1 max, Fe balance | ASTM A240 ASME SA240 | 0.29 (8.03) | 115 min (795 min) | 60 min (415 min) | 35 min | 100 Rockwell B max |
904L / N08904 | High efficiency furnace vent pipe, pulp & paper processing equipment, welding electrodes and fittings. | C 0.02 max, Mn 2.0 max, P 0.045 max, S 0.035 max, Si 1.0 max, Cr 19.0-23.0, Ni 23.0-28.0, Mo 4.0-5.0, N 0.1 max, Cu 1.0-2.0, Fe Balance | ASTM A240 ASME SB625 | 0.287 (7.95) | 71 min (490 min) | 31 min (220 min) | 35 min | 90 Rockwell B max |
N08367 | Desalination, seawater piping and critical components on offshore oil platforms | C 0.030 max, Mn 2.0 max, P 0.040 max, S 0.030 max, Si 1.0 max, Cr 20.0-22.0, Ni 23.5-25.5, Mo 6.0-7.0, N 0.18-0.25, Cu 0.75 max, Fe Balance (PREN 50.0 min) | ASTM A240, ASTM B688 ASME SA240, ASME SB688 | 0.291 (8.06) | 100 min (Sheet) / 95 min (Plate) (690 min / 655 min) | 45 min (310 min) | 30 min | 100 Rockwell B max |
N08367 | Desalination, seawater piping and critical components on offshore oil platforms. | C 0.030 max, Mn 2.0 max, P 0.040 max, S 0.030 max, Si 1.0 max, Cr 20.0-22.0, Ni 23.5-25.5, Mo 6.0-7.0, N 0.18-0.25, Cu 0.75 max, Fe Balance | ASTM A240, ASTM B688 ASME SA-240, ASME SB688 | 0.291 (8.06) | 100 min (sheet) / 95 min (plate) (690 min / 655 min) | 45 min (310 min) | 30 min | 100 Rockwell B max |
JS700? N08700 | Wet scrubbers in municipal incinerators, wet-process phosphoric acid plants, chlorine dioxide pulp bleaching | C 0.04 max, Mn 2.0 max, P 0.04 max, S 0.03 max, Si 1.0 max, Cr 19.0-23.0, Ni 24.0-26.0, Mo 4.3-5.0, Cu 0.5, Cb (8xC)min-0.4 max, Fe Balance | ASTM A240 ASTM B599 | 0.287 (7.95) | 80 min (550 min) | 35 min (240 min) | 30 min | 90 Rockwell B max |
Austenitic Stainless Steel / Super Austenitic Stainless Steel Comparison Chart
China GB | ISO Unified Digital Code | ASTM / ASME Grade | UNS Code | EN Code | Company Commercial Grade |
06Cr19Ni10 | S30408 | 304 | S30400 | 1.4301 | – |
07Cr19Ni10 | S30409 | 304H | S30409 | 1.4948 | – |
022Cr19Ni10 | S30403 | 304L | S30403 | 1.4307 | – |
022Cr19Ni10N | S30453 | 304LN | S30453 | 1.4311 | – |
– | – | Super304 | S30432 | – | Super304H(NSSMC) |
06Cr18Ni11Ti | S32168 | 321 | S32100 | 1.4541 | – |
07Cr18Ni11Ti | S32169 | 321H | S32109 | 1.494 | – |
06Cr17Ni12Mo2 | S31608 | 316 | S31600 | 1.4401 | – |
022Cr17Ni12Mo2 | S31603 | 316L | S31603 | 1.4404 | – |
022Cr17Ni12Mo2N | S31653 | 316LN | S31653 | 1.4406 | – |
06Cr17Ni12Mo3Ti | S31668 | 316Ti | S31635 | 1.4571 | – |
00Cr17Ni14Mo2 | 316LMoD/316LUG | S31603 | 1.4435 | – | |
022Cr19Ni13Mo3 | S31703 | 317L | S31703 | 1.4438 | – |
022Cr19Ni16Mo5N | S31723 | 317LMN | S31725 | 1.4439 | – |
06Cr25Ni20 | S31008 | 310S | S31008 | 1.4845 | – |
00Cr19Ni11 | – | 304L | S30403 | 1.4307 | 3RE12(Sandvik) |
– | – | 310L | S31002 | 1.4335 | 2RE10(Sandvik) |
20Cr25Ni20 | S31020 | 310H | S31009 | 1.4821 | |
16Cr25Ni20Si2 | S38340 | 314 | – | 1.4841 | |
022Cr25Ni22Mo2N | S31053 | 310MoLN | S31050 | 1.4466 | 2RE69(Sandvik) |
– | – | 310HCbN | S31042 | – | HR3C(NSSMC) |
07Cr18Ni11Nb | S34749 | 347H | S34709 | 1.4942 | – |
– | – | 347HFG | S34710 | – | – |
015Cr21Ni26M5Cu2 | S31782 | 904L | N08904 | 1.4539 | 2RK65(Sandvik) |
015Cr20Ni18Mo6CuN | S31252 | S31254 | S31254 | 1.4547 | 254 SMO (Sandvik) |
00Cr20Ni24Mo6N | – | N08367 | N08367 | – | AL6XN, AL6XN plus(ATI) |
00Cr21Ni25Mo6CuN | – | N08926 | N08926 | 1.4529 | – |
015Cr24Ni22Mo8Mn3CuN | S32652 | S32654 | S32654 | 1.4652 | 654SMO(Outokumpu) |
00Cr22Ni27Mo7CuN | – | S31277 | S31277 | – | – |
Related References:
Austenitic Stainless Steel
Superaustenitic Stainless Steel
Austenitic stainless steel for timber fixings
Austenitic Stainless Steel Grades Comparison Table
Effect of Austenitic Steel Composition and Heat Treatment
Compared Austenitic and Duplex Steel strength and vulnerable
Stress Relieving Heat Treatment for Austenitic Stainless Steel
Mechanism Measurement of Work Hardening Austenitic Steel
Composition Effect Magnetic Permeability of Austenitic Steel
Effect of Cold Work and Heat Treatment of Austenitic Stainless Steel