ISO/TR 15608 Material Group 10.1:
Austenitic ferritic stainless steels (Standard Duplex) with Cr ≤ 24,0 % and Ni > 4 %
Standard Duplex Steels ISO/TR 15608 Material Group 10.1
The duplex grades are used widely across all industry sectors. The primary factors that drive the use of duplex stainless steels are their improved stress corrosion cracking resistance and the potential to reduce cross sections in high-stress or high-pressure applications and tank construction. As with the other stainless steel families, the duplex grades have a range of corrosion resistance and can be divided into subgroups, depending on alloying content.
The standard duplex 2205 typically contain 21-25% chromium, 2-3% molybdenum and 0.15% nitrogen. Grades in this category are used widely across all industry sectors and 2205 (S31803/S32205) has become by far the most widely used duplex grade. The 2205 grade has a yield strength that is more than twice that of Type 316 and a pitting and crevice corrosion resistance that is similar to Type 904L austenitic stainless steel.
An empirical relationship called the Pitting Resistance Equivalent Number (PREN) has been developed to relate a stainless steels composition to its relative pitting resistance in chloride solutions.
For comparison: Austenitic steels (PREN = 24-25); Lean Duplex steels (PREN=21-32), Standard Duplex steels (PREN =32-40); Super Duplex (PREN = 40-48); Hyper Duplex steels (PREN >48).
Note: There is no exact definition for this classification
Applications for standard duplex grades include tanks, piping, process vessels and structural applications.
Weldability of Standard Duplex 2205 Steels ISO/TR 15608 Material Group 10.1
Duplex stainless steels have a very good cracking resistance due the high ferrite content, hot cracking is rarely a consideration when welding these steels. Therefore the problem of most concern in duplex steels are associated with the heat effect zone (HAZ) of welds. The HAZ problems can be loss of corrosion resistance , toughness, or post-weld cracking. To avoid these problems, the welding procedure should focus an minimising total time at temperature in the “red hot” range rather than managing the heat input for any one pass.
Preheating: As general guideline, the max. interpass temperature is limited to 150°C.
PWHT: Is not needed for Duplex stainless steels
Any post weld heat treatment should include full solution annealing followed by water quenching.
Typical material in material group 10.1
| Name/Type/Grade | Number | Standards | Product | Alloy | Remarks |
|---|---|---|---|---|---|
| X2CrNiN23-4 X2CrNiN23-4 X2CrNiN23-4 X2CrNiN23-4 – 2304 S32304 S32304 | 1.4362 1.4362 1.4362 1.4362 S32304 S32304 S32304 S32304 | EN 10028-7 EN 10272 EN 10216-5 EN 10217-7 ASTM A-240 ASTM A-928 ASTM A-790 ASTM A-789 | Plate Bar Seamless tube Welded tube Plate Welded pipe Smls. & welded pipe Smls. & welded tube | – – – – 2304 2304 2304 2304 | EN 13445-2 & EN 13480-2 & EN ISO 21009-1 EN 13445-2 & EN 13480-2 EN 13445-2 & EN 13480-2 EN 13445-2 & EN 13480-2 ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| X2CrNiMoSi18-5-3 S31500 S31500 | 1.4424 S31500 S31500 | EN 10216-5 ASTM A-789 ASTM A-790 | Seamless tube Smls. & welded tube Smls. & welded pipe | – – – | EN 13445-2 & EN 13480-2 ASME BPVC ASME BPVC |
| X2CrNiMoN22-5-3 X2CrNiMoN22-5-3 X2CrNiMoN22-5-3 X2CrNiMoN22-5-3 X2CrNiMoN22-5-3 X2CrNiMoN22-5-3 F51 F60 S32205 – – 2205 4A S31803 S31803 – S31803 | 1.4462 1.4462 1.4462 1.4462 1.4462 1.4462 S31803 S32205 S32205 S32205 S32205 S32205 J92205 S31803 S31803 S31803 S31803 | EN 10028-7 EN 10272 EN 10216-5 EN 10217-7 EN 10222-5 EN 10253-4 ASTM A-182 ASTM A-182 ASTM A-240 ASTM A-479 ASTM A-815 ASTM A-928 ASTM A-890 ASTM A-240 ASTM A-928 ASTM A-479 ASTM A-789 | Plate Bar Seamless tube Welded tube Forging Fitting Forging Forging Plate Bar Fitting Welded pipe Casting Plate Welded pipe Bar Smls. & welded tube | – – – – – – – 2205 2205 2205 2205 2205 CD3MN – – – – | EN 13445-2 & EN 13480-2 & EN ISO 21009-1 EN 13445-2 & EN 13480-2 EN 13445-2 & EN 13480-2 EN 13445-2 & EN 13480-2 EN 13445-2 & EN 13480-2 EN 13445-2 & EN 13480-2 ASME BPVC Code Case N-741 Code Case N-741 Code Case N-741 Code Case N-741 Code Case N-741 ASME BPVC ASME BPVC ASME BPVC ASME BPVC ASME BPVC |
| GX2CrNiMoN22-5-3 | 1.4470 | EN 10213 | Castings | – | EN 13445-2 |
Read More
Lean Duplex steel: ISO/TR 15608 Group 10.3
Super Duplex steel: ISO/TR 15608 Group 10.2
Suitable Standard-Duplex and Super-Duplex steels for Pressure Equipments
