Austenitic stainless steel is one of the five classes of stainless steel by crystalline structure (along with ferritic, martensitic, duplex and precipitation hardened). Its primary crystalline structure is austenite (face-centered cubic). These steels usually cannot be hardened by heat treatment and are non-magnetic. This structure is achieved by adding enough austenite stabilizing elements such as nickel, manganese and nitrogen.
Like the austenitic stainless steels, the super austenitic stainless steels are also very ductile; they have excellent toughness, high strength, excellent corrosion resistance, good weldability and excellent formability. The super austenitic stainless steels are generally used where higher corrosion resistance, especially protection against chloride pitting and crevice corrosion, is required. Super austenitic stainless steels are defined as austenitic iron-based alloys with a PREN value greater than 40.
| Alloy | BÖHLER brand | WstNo. | UNS | ISO | AMS | ASTM | Others |
|---|---|---|---|---|---|---|---|
| 304 | A500 | 1.4301 | S30400 | X5CrNi18-10 | – | A182 | AISI: 304 |
| 304L | A607 | 1.4307 | S30403 | X2CrNi18-9 | – | A182 | AISI: 304L |
| 316 | A120 | 1.4401 | S31600 | X5CrNiMo17-12-2 | – | A182 | AISI: 316 |
| 316L | A200 | 1.4404 | S31600 | X2CrNiMo17-12-2 | – | A182 | AISI: 316L |
| 316L | A220 | 1.4435 | S31603 | X2CrNiMo18-14-3 | – | – | AISI: 316LUG, STN: 17 350 |
| 317L | A102 | 1.4449 | S31703 | X3CrNiMo18-12-3 | – | A182 | AISI: 317L |
| 310 Urea | A405 | 1.4466 | S31050 | X1CrNiMoN25-22-2 | – | – | AISI: 310 MoLN |
| 321 | A700 | 1.4541 | S32100 | X6CrNiTi18-10 | – | A182 | AISI: 321 |
| 347 | A750 | 1.4546, 1.4550 | N07090 | X6CrNiNb18-10 | 5512, 5646 | AISI: 347 | |
| – | P558 | 1.3808 | S29225 | X20CrMnMoN17-11-3 | |||
| Alloy 50 | P511 | Nitronic 50 | S20910 | X3CrNiMnMo22-13-3-2 | – | A182, A276, A479 | AISI: XM 19 |
| U-Boot Stahl 1.3964 | P501 | 1.3964 | X2CrNiMnMoNNb21-16-5-3 | ||||
| U-Boot Stahl 1.3974 | P503 | 1.3974 | X2CrNiMnMoNNb23-17-6-3 | ||||
| 316LN/ U-Boot Stahl 1.3952 | P510 | 1.4429 | X2CrNiMoN17-13-3 | 316LN | |||
| Alloy 904L | A962RC | 1.4539 | N08904 | X1NiCrMoCu25-20-5 | – | A182 | – |
| 254SMO | A965SA | 1.4547 | S31254 | X1CrNiMoCuN20-18-7 | – | – | AISI: F44 |
| Alloy 926, Alloy 6XN | A970 | 1.4529 | N08926 | X1CrNiMoCuN20-18-7 | – | – | – |
| Alloy 24 | P500 | 1.4565 | X2CrNiMnMoN25-18-6-5 | Alloy 24 | |||
| Alloy 31 | A952 | 1.4562 | N08031 | X1NiCrMoCu32-28-7 | – | B564, B649 | – |
| Alloy 60 | P513 | – Nitronic 60 | S21800 | X10CrNiMn17-8-8 | – | A276, A314, A479, A484 | – |