DONGSHANG Stainless produces ASTM A789 duplex stainless steel tube applied for boiler, heat exchanger, super-heater, duplex grade in ASTM 2205, AISI UNS S32205 and EN steel No. 1.4462, duplex steels are also used for seamless stainless steel tube in specific applications, duplex steels have more high strength and excellent corrosion resistance.
2205/1.4462 Duplex Chemical Composition
2205 duplex stainless steel contains 22% chromium, 5% nickel, 3.2% molybdenum and other alloying elements such as nitrogen and manganese, approximately 40-50% ferrite.
| C | Mn | Si | P | S | Cr | Mo | Ni | N | |
|---|---|---|---|---|---|---|---|---|---|
| 2205 (S31803) | 0.03 | 2.0 | 1.0 | 0.03 | 0.02 | 21.0 – 23.0 | 2.5 – 3.5 | 4.5 – 6.5 | 0.08 – 0.20 |
| 2205 (S32205) | 0.03 | 2.0 | 1.0 | 0.03 | 0.02 | 22.0 – 23.0 | 3.0 – 3.5 | 4.5 – 6.5 | 0.14 – 0.20 |
| 1.4462 | 0.03 | 2.0 | 1.0 | 0.035 | 0.015 | 21.0-23.0 | 2.50-3.50 | 4.5-6.5 | 0.10-0.22 |
S31803, 2205 and other duplex grades are typical materials for ASTM A789 / ASME SA789 seamless and welded tubes, these Ferritic / Austenitic steels have high chromium and molybdenum low nickel content compared with 18 – 8 stainless steels, more thin thickness bring high cost-effective, so duplex tubes widely used in oil, gas, chemical, petrifaction industries heating system, super duplex steels are more effective, duplex steel features and mechanical properties, see more duplex stainless steel pipe and 2205 stainless steel pipe.
ASTM A789 is a specification for seamless stainless steel tube applied in heat exchanger, boiler, super heater, grades not include duplex stainless steel grades, considering features and advantages of duplex steels, it can be used for tubes in many industries, A789 and A790 are specifications for duplex stainless steel tubes and pipes for general service.
Apart from duplex steel grades, alloy steel and Austenitic steels are covered complying with ASTM A789, for example, ASTM A789 UNS32205 Seamless Steel Tube, ASTM A789 2205 Seamless Stainless Steel Tube.