What is UNS S32205 material?
UNS S32205 is a two-phase, ferritic, austenitic stainless steel alloyed with 22% chromium, 3% molybdenum, and 5–6% nickel. It is the most popular grade of duplex stainless steel and has a yield strength that is twice as high as that of austenitic stainless steel’s normal grades. It has great performance in the majority of caustic environments, high resistance to pitting and crevice corrosion, and good weldability.
S32205 Applications
pulp mills
food processing
oil and gas piping,
chemical processing, and more.
What is UNS S31803 material?
Duplex grade UNS S31803 has a ferritic-austenitic composition. When annealed, this metal has a ferrite content of between 40 and 50 percent. The duplex microstructure maintains the austenitic classes’ corrosion resistance while having the high strength of the ferritic grades.
S31803 Application
Flue gas filters
Chemical tanks
Heat exchangers
Acetic acid distillation elements
S31803 and S32205 Chemical Composition
| UNS | Carbon | Phosphorus | Sulphur | Silicon | Manganese | Nickel | Molybdenum | Nickel | Chromium |
| S31803 | 0.03max | 0.03max | 0.02max | 1.00max | 2.00 max | 0.08-0.2 | 2.5-3.5 | 4.5-6.5 | 21.0-23.0 |
| S32205 | 0.03max | 0.03max | 0.02max | 1.00max | 2.00 max | 0.14-0.2 | 3.0-3.5 | 4.5-6.5 | 22.0-23.0 |
S31803 and S32205 Mechanical Properties
| UNS | Tensile strength, min, Mpa | Yield strength, 0.2% offset, min, Mpa, | Elongation, A5% |
| S31803 | 620 | 450 | 25 |
| S32205 | 655 | 450 | 25 |
S31803 and S32205 Workabiliy
They have high thermal strength that is comparable to Type 430 in the 950–1150°C range. However, below 900°C, it exhibits a sharp rise in strength. Care must be taken when working with cool materials because they exhibit higher proof stress and lower elongation than Type 304.
S31803 and S32205 Weldability
The typical austenitic stainless steel can be welded using a variety of techniques, such as TIG welding, shielded metal arc welding, and plasma welding. The use of welding tools is advised. There is no need for preheating or post-heating. In order to avoid intermetallic production during welding, the interpass temperature should not be higher than 100°C.
S31803 and S32205 Heat Treatment
At 1040°C or greater, the solution annealing should be carried out. After that, it should be quickly cooled using water or another method.
S31803 and S32205 Pickling
Nitric acid and fluoric acid are combined for marinating. However, alkali immersion before acid pickling, if feasible, shot blasting, and because descaling is somewhat more difficult than with Type 304, are very effective.
S31803 vs. S32205: Distinguishable Differences
First off, UNS S31803 and S32205 are alloys that share more traits than they do unique ones. They are both stainless steel with similar elemental compositions. Both UNS S31803 and S32205 are members of the duplex 2205 family, which implies that austenite and ferrite are present in nearly equal amounts in both of them. Second, they are both extraordinarily robust and long-lasting metals. Both S31803 and S32205 are used in some of the more arduous and hostile manufacturing processes that call for materials that can withstand repeated and prolonged trips through the proverbial ringer.
The main difference between the two is that UNS S32205 has a greater nitrogen content, adding an additional layer of protection to an already sturdy surface. A further layer of defence against any corrosive substances attempting to assault and eat into the steel solution is provided by the presence of treated nitrogen. The improved corrosion resistance of UNS S32205 gives it a small but significant advantage over its nearest rival.
The icing on the cake is that the advent of nitrogen has increased its capacity to defend itself. It enhances the ability of a piece of duplex steel that was previously extremely dependable to guard against damage and maintain the standard of any application.
Read More :
Understanding the Applications & Uses of Duplex Stainless Steels: Duplex stainless steels belong to the stainless steel family. These are referred to as duplex grades because their metallurgical structure comprises two phases, austenite, and ferrite, in approximately equal quantities.
