Ferritic stainless steels contain little to no nickel in the composition. They have chromium in high amounts, in some cases up to 27% but the lack of nickel makes them prone to corrosion of all sorts. However, the strength is higher than or equal to their austenitic counterparts. The austenitic stainless steels have chromium and nickel in the composition with some grades having molybdenum in the content. This provides the materials with good strength and added corrosion resistance.
The heat treatment methods involve heating up to a higher temperature and cooling of the materials. Since the ferritic and austenitic steels have carbon in their composition, heating up to elevated temperatures would result in the formation of chromium carbide grains which would reduce the corrosion resistance dramatically. Also, the heat treatment procedures doe not change the austenitic grain structure in a way to improve the strength. Even after compromising the corrosion resistance, the heat treatment doesn’t result in high strength. Therefore bot the austenitic and ferritic steels are not heat treated.
Forging is the process hammering the heated steel with high pressures to shape them into the desired forms. Austenitic and ferritic steels can be forged to make the different products made in these steels. The forging allows to reduce the surface porosity which also provides a fine grain structure to the product. The forging process improves the tensile strength, fatigue strength and the lifespan of the products. With forging, the products also become ductile. For these advanced properties, the forged products are preferred in most applications.
Both these steels could not be heat treated. Heat treatment is a process that involves heating up the product after manufacture. Instead, these materials could be annealed, a heating and cooling process that is employed during manufacturing. The annealing does not improve the strength, but it improves the hardness of the material. The austenitic stainless steels are the ones that are mostly annealed to retain the corrosion resistance and improve the hardness. The ferritic steel types generally don’t require annealing.
Irradiation is a process of removing neutrons from the nuclei of an atom. The irradiation processes take place in high temperature applications, especially in the nuclear power generation and other nuclear related activities. When steels are exposed to irradiation temperatures and environments, they get irradiated and the yield strength decreases greatly. To avoid the irradiation effect, the steels have to be kept at optimum temperatures. The materials do not irradiate faster under a range of temperature. The different grades of steels would have different optimum temperatures.
The grain structure in the metallurgic microstructure defines the ferritic, austenitic, martensitic and duplex steel types. The austenite or gamma phase iron is the forming particle of the austenitic stainless steel. It is a non-magnetic particle structure. The ferrite on the other hand has high magnetic properties in the microstructure. The selection of these materials for various applications consider these magnetic properties in addition to the strength and corrosion resistance.
| EN Grade | ASTM Grade | UNS | Austenitic (A) or Ferritic (F) Stainless Steel | Rp 0.2 | Rp 1.0 | Rm | Elongation A | Elongation A80 | Hardness | Hardness |
|---|---|---|---|---|---|---|---|---|---|---|
| MPa | MPa | MPa | % | % | HR | HB | ||||
| 1.4000 | TYPE 410S | S41008 | F | > 240 | 400 - 600 | > 19 | > 19 | |||
| 1.4003 | S40977 | F | > 280 | 450 - 650 | > 20 | > 20 | ||||
| 1.4016 | TYPE 430 | S43000 | F | > 260 | 430 - 600 | > 20 | > 20 | |||
| 1.4510 | TYPE 439 | S43035 | F | |||||||
| 1.4512 | TYPE 409 | S40900 | F | > 220 | 380 - 560 | > 25 | > 25 | |||
| 1.4520 | F | |||||||||
| 1.4589 | F | |||||||||
| A | ||||||||||
| 1.4301 | TYPE 304 | S30400 | A | > 230 | > 260 | 540 - 750 | > 45 | > 45 | ||
| 1.4303 | TYPE 305 | S30500 | A | > 220 | > 250 | 500 - 650 | ||||
| 1.4306 | TYPE 304L | A | > 220 | > 250 | 520 - 700 | > 45 | > 45 | |||
| 1.4307 | TYPE 304L | S30403 | A | > 220 | > 250 | 520 - 700 | > 45 | > 45 | ||
| 1.4310 | TYPE 301 | S30100 | A | > 250 | > 280 | 600 - 950 | > 40 | > 40 | ||
| 1.4318 | TYPE 301LN | S30153 | A | > 350 | > 380 | 650 - 850 | > 40 | > 35 | ||
| 1.4372 | TYPE 201 | S20100 | A | > 350 | > 380 | 680 - 880 | > 45 | > 45 | ||
| 1.4509 | S43940 | F | > 230 | 430 - 630 | > 18 | > 18 | ||||
| 1.4513 | F | |||||||||
| 1.4541 | TYPE 321 | S32100 | A | > 220 | > 250 | 520 - 720 | > 40 | > 40 | ||
| 1.4550 | TYPE 347H | S34709 | A | |||||||
| 1.4622 | S44330 | F | > 300 | 430 - 630 | > 22 | |||||
| 1.4401 | TYPE 316H | S31609 | A | > 240 | > 270 | 530 - 680 | > 40 | > 40 | ||
| 1.4404 | TYPE 316L | S31603 | A | > 240 | > 270 | 530 - 680 | > 40 | > 40 | ||
| 1.4420 | S31655 | A | > 350 | > 380 | 650 - 850 | > 35 | ||||
| 1.4432 | TYPE 316L | A | > 240 | > 270 | 550 - 700 | > 40 | > 40 | |||
| 1.4435 | TYPE 316L | A | > 240 | > 270 | 550 - 700 | > 40 | > 40 | |||
| 1.4436 | TYPE 316 | A | > 240 | > 270 | 550 - 700 | > 40 | > 40 | |||
| 1.4521 | TYPE 444 | S44400 | F | > 300 | 420 - 640 | > 20 | > 20 | |||
| 1.4571 | TYPE 316Ti | S31635 | A | > 240 | > 270 | 540 - 690 | > 40 | > 40 | ||
| 1.4462 | S32205 | D | > 500 | 700 - 950 | > 20 | > 20 | ||||
| 1.4362 | S32304 | D | > 450 | 650 - 850 | > 20 | > 20 | ||||
| 1.4410 | S32750 | D | > 550 | 750 - 1000 | > 20 | > 20 | ||||
| 1.4016 | TYPE 430 | S43000 | F | > 260 | 430 - 600 | > 20 | > 20 | |||
| 1.4301 | TYPE 304 | S30400 | A | > 230 | > 260 | 540 - 750 | > 45 | > 45 | ||
| 1.4307 | TYPE 304L | S30403 | A | > 220 | > 250 | 520 - 700 | > 45 | > 45 | ||
| 1.4310 | TYPE 301 | S30100 | A | > 250 | > 280 | 600 - 950 | > 40 | > 40 | ||
| 1.4318 | TYPE 301LN | S30153 | A | > 350 | > 380 | 650 - 850 | > 40 | > 35 | ||
| 1.4376 | A | > 400 | > 420 | 600 - 900 | > 40 | > 40 | ||||
| 1.4401 | TYPE 316H | S31609 | A | > 240 | > 270 | 530 - 680 | > 40 | > 40 | ||
| 1.4404 | TYPE 316L | S31603 | A | > 240 | > 270 | 530 - 680 | > 40 | > 40 | ||
| 1.4420 | S31655 | A | > 350 | > 380 | 650 - 850 | > 35 | ||||
| 1.4501 | S32760 | D | ||||||||
| 1.4571 | TYPE 316Ti | S31635 | A | > 240 | > 270 | 540 - 690 | > 40 | > 40 | ||
| FDX 27 | S82031 | D | ||||||||
| 1.4162 | S32101 | D | > 530 | 700 - 900 | > 30 | > 20 | ||||
| 1.4662 | S82441 | D | > 550 | 750 - 900 | > 25 | > 20 | ||||
| 1.4547 | S31254 | A | > 320 | > 350 | 650 - 850 | > 35 | > 35 | |||
| 1.4438 | TYPE 317L | S31703 | A | |||||||
| 1.4529 | N08926 | A | ||||||||
| 1.4652 | S32654 | A | > 430 | > 470 | 750 - 1000 | > 40 | > 40 | |||
| 1.4466 | S31050 | A | ||||||||
| 1.4539 | N08904 | A | > 240 | > 270 | 530 - 730 | > 35 | > 35 | |||
| A | ||||||||||
| 1.4006 | TYPE 410 | S41000 | M | < 600 | > 20 | > 20 | ||||
| 1.4021 | TYPE 420 | M | < 700 | > 15 | ||||||
| 1.4024 | M | < 650 | > 20 | > 20 | ||||||
| 1.4031 | M | < 760 | > 12 | > 12 | ||||||
| 1.4034 | M | < 780 | > 12 | > 12 | ||||||
| 1.4110 | M | < 850 | > 12 | > 12 | ||||||
| 1.4116 | M | < 850 | > 12 | > 12 | ||||||
| 1.4122 | M | < 900 | > 12 | > 12 | ||||||
| PH | < 1275 | > 5 | > 5 | |||||||
| 1.4568 | TYPE 631 | PH | < 1030 | > 19 | > 19 | |||||
| 1.4835 | S30815 | A | > 310 | > 350 | 650 - 850 | > 40 | > 37 | |||
| 1.4724 | F | |||||||||
| 1.4828 | A | > 230 | > 270 | 550 - 750 | > 30 | > 28 | ||||
| 1.4833 | TYPE 309S | S30908 | A | > 210 | > 250 | 500 - 700 | > 35 | > 33 | ||
| 1.4841 | TYPE 314 | A | ||||||||
| 1.4845 | TYPE 310S | S31008 | A | > 210 | > 250 | 500 - 700 | > 33 | |||
| 1.4948 | TYPE 304H | S30409 | A | > 230 | > 260 | 530 - 740 | > 45 | > 45 | ||
| 1.4305 | TYPE 303 | A | ||||||||
| 1.4307 | TYPE 304L | S30403 | A | > 220 | > 250 | 520 - 700 | > 45 | > 45 | ||
| 1.4404 | TYPE 316L | S31603 | A | > 240 | > 270 | 530 - 680 | > 40 | > 40 | ||
| PH | < 1275 | > 5 | > 5 |
| GRADE | EN | WEIGHT % | |
|---|---|---|---|
| CR | OTHER ELEMENTS | ||
| 405 | 1.4000 | 12.0 - 14.0 | - |
| 409L | 1.4512 | 10.5 - 12.5 | 6(C+N)<Ti<0.65 |
| 410L | 1.4003 | 10.5 - 12.5 | 0.3<Ni<1.0 |
| 430 | 1.4016 | 16.0 - 18.0 | - |
| 439 | 1.4510 | 16.0 - 18.0 | 0.15+4(C+N)<Ti<0.8 |
| 430Ti | 1.4511 | 16.0 -18.0 | Ti: 0.6 |
| 441 | 1.4509 | 17.5 - 18.5 | 0.1<Ti<0.6
0.3+3C<Nb<1.0 |
| 434 | 1.4113 | 16.0 - 18.0 | 0.9<Mo<1.4 |
| 436 | 1.4513 | 16.0 - 18.0 | 0.9<Mo<1.4
0.3<Ti<0.6 |
| 444 | 1.4521 | 17.0 - 20.0 | 1.8<Mo<2.5
0.15+4(C+N)<Ti+Nb<0.8 |
| 447 | 1.4592 | 28 - 30.0 | 3.5<Mo<4.5
0.15+4(C+N)<Ti<0.8 |
| EURONORM (EN) / WERKSTOFF NUMBER | EN DESIGNATION | AISI / SS | MO | C | CR | NI | OTHERS |
|---|---|---|---|---|---|---|---|
| 1.4310 | X10CrNi18-8 | 301 | NS | 0.10 | 17.5 | 8 | NS |
| 1.4301 | X5CrNi18-10 | 304 | NS | < 0.07 | 18.5 | 9 | NS |
| 1.4307 | X2CrNi18-9 | 304L | NS | < 0.030 | 18.5 | 9 | NS |
| 1.4305 | X8CrNiS18-9 e | 303 | NS | < 0.10 | 18 | 9 | 0.3 |
| 1.4541 | X6CrNiTi18-10 | 321 | NS | < 0.08 | 18 | 10.5 | Ti: 5×C ≤ 0.70 |
| 1.4401 | X5CrNiMo17-12-2 | 316 | 2.2 | < 0.07 | 17.5 | 11.5 | NS |
| 1.4404 | X2CrNiMo17-12-2 | 316L | 2.25 | < 0.030 | 17.5 | 11.5 | NS |
| 1.4571 | X6CrNiMoTi17-12-2 | 316Ti | 2.25 | < 0.08 | 17.5 | 12 | Ti: 5×C ≤ 0.70 |
