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.

904L Stainless Steel Pipe — Super-Austenitic Stainless Steel Pipe

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	–	–