Since pricing and corrosion resistance are both equally important when deciding a grade for a particular selection. In case of Duplex and Stainless Steel 316, there is no clear winner. Metline Industries supplies high quality Duplex stainless steel 2205 rods and bars, as well as Stainless Steel 316L stainless steel bars and rods. Both grades have their special qualities, due to which they are accepted for wide range of applications across various industry verticals.

While, reading and gather information both the grades – we came across some important observations, as below:

In terms of “Corrosion Resistance” – Duplex stainless steels exhibit a high level of corrosion resistance in most environments where the standard austenitic grades are useful.However, there are some notable exceptions where they are decidedly superior. This results from their high chromium content, which is beneficial in oxidizing acids, along with sufficient molybdenum and nickel to provide resistance in mildly reducing acid environments. The relatively high chromium, molybdenum and nitrogen also give them very good resistance to chloride pitting and crevice corrosion. Their duplex structure is an advantage in potential chloride stress corrosion cracking environments. Duplex alloys are more resistant to chloride stress corrosion cracking than Types 304 and 316.

With Respect to “Pitting and Crevice Corrosion Resistance” – The high chromium, molybdenum and nitrogen contents in duplex grades provide very good resistance to chloride-induced localized corrosion in aqueous environments. All but the very lowest alloyed duplex stainless steels are far superior to Type 316 in this respect. Depending on the alloy content, some duplex grades are among the best performing stainless steels. Because they contain relatively high chromium content, duplex stainless steels provide a high level of corrosion resistance very economically. A comparison of pitting and crevice corrosion resistance for a number of stainless steels in the solution annealed condition as measured by the ASTM G 48 procedures (10% ferric chloride) is given in Figure 1. Critical temperatures for materials in the as-welded condition would be expected to be somewhat lower. Higher critical pitting ( CPT) or crevice corrosion temperatures (CCT) indicate greater resistance to the initiation of these forms of corrosion. The CPT and CCT of 2205 are well above those of Type 316. This makes 2205 a versatile material in applications where chlorides are concentrated by evaporation, as in the vapor spaces of heat exchangers or beneath insulation. The CPT of 2205 indicates that it can handle many brackish waters and de-aerated brines. It has been successfully used in seawater applications where the surface has been maintained free of deposits through high flow rates or other means. Figure 2 shows the CCT as a function of PRE number.

Metline Industries is one of the biggest steel bars and rods manufacturer and suppliers in India with more than 20 years exports and domestic sales experience. We are specialized in supplying both stainless steel duplex round bars and stainless steel 316L round bars, stainless steel angles and stainless steel flat bars with competitive price and high quality. The quality of our stainless steel bars are highly accepted in the US, UK, Saudi Arabia, Kuwait, UAE, Australia, Qatar, Bahrain, Singapore, Africa and many other countries.

Designation Various Stainless Steel Grades – Equivalents

AISIEN / DINASTM/UNSENAFNORReg.TMForging 
410S1. 4000S41008X6Cr13Z8C12Ferrite
4101. 4006S41000X12Cr13Z10C13A182 F410Martensite
4301. 4016S43000X6Cr17Z8C17Ferrite
4201. 4021S42000X20Cr13Z20C13Martensite
4201. 4028J91153X30Cr13Z33C13Martensite
1. 4162S32101LDX 2101Duplex
3041. 4301S30400X5CrNi18.10Z6CN18.09A182 F304Austenite
304L1. 4306S30403X2CrNi19.11A182 F304LAustenite
304L1. 4307A182 F304LAustenite
1. 4362S32304/S 39230X2CrNiN23.4Z3CN23.04AzSAF 2304Superduplex
3161. 4401S31600X5CrNiMo17.12.2Z7CND17.11.02 A182 F316Austenite
316L1. 4404S31603X2CrNiMo17.13.2Z3CND18.12.02 A182 F316LAustenite
1. 4410S32750X2CrNiMoN25.7.4Z3CND25.07AzSAF 2507A182 F53Superduplex
316L1. 4435S31609X2CrNiMo18.14.3Z3CND18.14.03Austenite
(Mo+)
3161. 4436X5CrNiMo17.13.3Z6CND18.12.03Austenite
(Mo+)
317L1. 4438S31703X2CrNiMo18.16.4Z3CND19.15.04A182 F317LAustenite
1. 4462S31803/S32205X2CrNiMoN22.5.3Z3CND22.05AzSAF 2205A182 F51Duplex
 1. 4501S32760X2CrNiMoCuWN25.7.4 Zeron 100A 182 F55Duplex
4091. 4512Ferrite
904L1. 4539N 08904X1NiCrMoCu25.20.5Z2NCDU25.20Uranus B6/2 RK 65625 N08904Austenite
3211. 4541S32100X6CrNiTi18.10Z6CNT18.10Uranus 65 / SS25LA182 F321Austenite
6301. 4542S17400X5CrNiCunB17.4Z7CNU17.0417.4 PHA564 630
1. 4547S31254254SmoA182 F44Austenite
3471. 4550S34700X6CrNiTi18.10Z6CNNb18.10A182 F347Austenite
(H)
316Ti1. 4571S31635X6CrNiMoTi17.12.2Z6CNDT17.12A182 F316TiAustenite
1. 4652S32654654SmoAustenite
1. 4662S82441LDX 2404Duplex
1. 4713X10CrAlSi7Z8Ca7Sicromal 8Ferrite
1. 4724X10CrAlSi13Z13C13Sicromal 9Ferrite
4421. 4742S44200X10CrAlSi18Z12CAS18Sicromal 10Ferrite
1. 4762X10CrAlSi24Z12CAS25Sicromal 12Ferrite
1. 4818S30415153 MAAustenite
302 B1. 4828S30215/30900X15CrNiSi20-12A182 F309Austenite
309
309S1. 4833S30908X6CrNi22.13Z15CN24.13Austenite
1. 4835S30815X9CrNiSiNCe21-11-2253 MAAustenite
3101. 4841S31000/31400X15CrNiSi25.20Z15CNS25.20Austenite
310S1. 4845S31008X12CrNi25.21Z8CN25.20A182 F310SAustenite
321H1. 4878S32109X12CrNiTi18.9Z6CNT18.12Austenite
316H1. 4919S31609X6CrNiMo17.13Z6CND17.12S31609Austenite
304H1. 4948S30409X6CrNi18.11Z6CN18.11S30409Austenite