{"id":103,"date":"2026-07-21T10:09:34","date_gmt":"2026-07-21T10:09:34","guid":{"rendered":"https:\/\/www.siddhgiritubes.com\/blog\/?p=103"},"modified":"2026-07-21T10:09:34","modified_gmt":"2026-07-21T10:09:34","slug":"duplex-2205-vs-super-duplex-2507","status":"publish","type":"post","link":"https:\/\/www.siddhgiritubes.com\/blog\/duplex-2205-vs-super-duplex-2507\/","title":{"rendered":"Duplex 2205 vs Super Duplex 2507"},"content":{"rendered":"

\"Duplex<\/h2>\n

2507 Super Duplex is engineered for higher load bearing capacity<\/h2>\n

What is Duplex 2205?<\/strong><\/p>\n

Duplex 2205 is high performance alloy which is used in application which requires good corrosion resistance and strength. It contains upto 22% chromium, 5% Nickel and upto 3% Molybdenum. Additionally nitrongen is added in it to boost its mechanical strength and pitting resistance. Duplex 2205 is the cost effective solution for less aggressive environments.<\/p>\n

What is Super Duplex 2507?<\/strong><\/p>\n

Super Duplex 2507 is known for its exceptional strength and superior corrosion resistance and primarily used in chloride rich marine and industrial environments. It belongs to duplex family which means it has mixed microstructure of austenite and ferrite. It contains roughly 25% chromium, 7% nickel, 4% molybdenum, and nitrogen. Alloy 2507 has Extremely High Mechanical Strength and Resistance to High Temperature and Pressure.<\/p>\n

SAF 2507 is approximately 25% stronger than Alloy 2205 material<\/h3>\n

Chemical Composition of Super Duplex 2507 Vs Duplex 2205<\/strong><\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n
Element<\/th>\nDuplex 2205<\/a><\/th>\nSuper Duplex 2507<\/a><\/th>\nWhy It Matters<\/th>\n<\/tr>\n
Chromium (Cr)<\/td>\n21.0 \u2013 23.0%<\/td>\n24.0 \u2013 26.0%<\/td>\nPrimary corrosion barrier<\/td>\n<\/tr>\n
Molybdenum (Mo)<\/td>\n2.5 \u2013 3.5%<\/td>\n3.5 \u2013 4.5%<\/td>\nPitting & crevice resistance<\/td>\n<\/tr>\n
Nickel (Ni)<\/td>\n4.5 \u2013 6.5%<\/td>\n6.0 \u2013 8.0%<\/td>\nAustenite stabiliser, SCC resistance<\/td>\n<\/tr>\n
Nitrogen (N)<\/td>\n0.14 \u2013 0.20%<\/td>\n0.24 \u2013 0.32%<\/td>\nStrengthens & boosts PREN<\/td>\n<\/tr>\n
Carbon (C)<\/td>\n\u2264 0.030%<\/td>\n\u2264 0.030%<\/td>\nKept low to prevent sensitisation<\/td>\n<\/tr>\n
Manganese (Mn)<\/td>\n\u2264 2.0%<\/td>\n\u2264 1.2%<\/td>\nAustenite former<\/td>\n<\/tr>\n
Silicon (Si)<\/td>\n\u2264 1.0%<\/td>\n\u2264 0.80%<\/td>\nDeoxidiser<\/td>\n<\/tr>\n
Phosphorus (P)<\/td>\n\u2264 0.030%<\/td>\n\u2264 0.035%<\/td>\nKept low \u2014 impairs toughness<\/td>\n<\/tr>\n
Sulphur (S)<\/td>\n\u2264 0.020%<\/td>\n\u2264 0.020%<\/td>\nKept low \u2014 impairs corrosion resistance<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Super Duplex 2507 has higher chromium, molybdenum, and nitrogen compared to Alloy 2205<\/p>\n

Comparison of SAF 2507 vs Alloy 2205 Mechanical Properties<\/strong><\/p>\n

\n\n\n\n\n\n\n\n\n
Property<\/th>\nUNS S31803<\/th>\nUNS S32750<\/th>\n<\/tr>\n
Proof Strength (min)<\/td>\n450 MPa<\/td>\n550 MPa<\/td>\n<\/tr>\n
Tensile Strength<\/td>\n620 \u2013 820 MPa<\/td>\n750 \u2013 950 MPa<\/td>\n<\/tr>\n
Hardness (Brinell, max)<\/td>\n293 HBW<\/td>\n310 HBW<\/td>\n<\/tr>\n
Impact Toughness (Charpy)<\/td>\nGood down to \u201346\u00b0C<\/td>\nGood down to \u201350\u00b0C<\/td>\n<\/tr>\n
Density<\/td>\n7.82 g\/cm\u00b3<\/td>\n7.80 g\/cm\u00b3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Super Duplex 2507 has higher PREN value compared to SAF 2205<\/h4>\n

Corrosion Resistance: 2205 vs 2507<\/strong><\/p>\n

\n\n\n\n\n\n\n
Property<\/th>\nDuplex Steel 2205<\/th>\nSAF 2507<\/th>\n<\/tr>\n
PREN (Pitting Resistance)<\/td>\n~34\u201336<\/td>\n~40\u201345<\/td>\n<\/tr>\n
Chloride Environment Performance<\/td>\nStrong<\/td>\nExceptiona<\/td>\n<\/tr>\n
Best For<\/td>\nModerate chloride and industrial use<\/td>\nSevere offshore and marine conditions<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Difference between Thermal Properties and Temperature Limits of Duplex 2205 vs SDSS 2507<\/strong><\/p>\n

\n\n\n\n\n\n\n\n\n
Thermal Property<\/th>\nWNR 1.4462<\/th>\nWNR 1.4410<\/th>\n<\/tr>\n
Max continuous service temp<\/td>\n300\u00b0C (572\u00b0F)<\/td>\n280\u00b0C (536\u00b0F)<\/td>\n<\/tr>\n
Thermal conductivity (20\u00b0C)<\/td>\n19 W\/m\u00b7K<\/td>\n14 W\/m\u00b7K<\/td>\n<\/tr>\n
Low-temperature service limit<\/td>\n\u201346\u00b0C (\u201351\u00b0F)<\/td>\n\u201350\u00b0C (\u201358\u00b0F)<\/td>\n<\/tr>\n
Sigma phase embrittlement risk<\/td>\nAbove 300\u00b0C<\/td>\nAbove 280\u00b0C<\/td>\n<\/tr>\n
475\u00b0C embrittlement risk<\/td>\nAbove 300\u00b0C<\/td>\nAbove 280\u00b0C<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Weldability and Fabrication of DSS 2205 vs Alloy 2507<\/strong><\/p>\n

\n\n\n\n\n\n\n
Property<\/th>\nSDSS 2507<\/th>\nSAF 2205<\/th>\n<\/tr>\n
Filler metal<\/td>\nER2594 for GMAW\/GTAW<\/td>\nER2209 for GMAW<\/td>\n<\/tr>\n
Heat input<\/td>\nVery controlled \u2014 typically 0.2 to 1.5 kJ\/mm<\/td>\nLow to medium \u2014 typically 0.5 to 1.5 kJ\/mm<\/td>\n<\/tr>\n
Interpass temperature<\/td>\nMaximum 100\u00b0C<\/td>\nMaximum 150\u00b0C<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
SDSS 2507 typically costs 30\u201350% more than Alloy 2205<\/h5>\n

Cost Comparison of Duplex 2205 vs Super Duplex 2507<\/strong><\/p>\n

\n\n\n\n\n\n\n\n\n\n
Cost Factor<\/th>\nDuplex 2205<\/th>\nSuper Duplex 2507<\/th>\n<\/tr>\n
Raw material premium vs 316L<\/td>\n~30\u201360% higher<\/td>\n~80\u2013130% higher<\/td>\n<\/tr>\n
Price relative to 2205<\/td>\nBaseline (1\u00d7)<\/td>\nApproximately 1.5 \u2013 2.0\u00d7<\/td>\n<\/tr>\n
Fabrication cost premium<\/td>\nLow<\/td>\nModerate<\/td>\n<\/tr>\n
Inventory availability<\/td>\nHigh<\/td>\nLower<\/td>\n<\/tr>\n
Wall thickness savings<\/td>\nSome reduction vs 316L<\/td>\nGreater reduction due to higher strength<\/td>\n<\/tr>\n
Life cycle cost<\/td>\nHigher maintenance<\/td>\nLower maintenance<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Features of Duplex Steel 2507 VS 2205<\/strong><\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nDuplex 2205<\/th>\nSuper Duplex 2507<\/th>\n<\/tr>\n
UNS Number<\/td>\nS31803 \/ S32205<\/td>\nS32750<\/td>\n<\/tr>\n
EN Number<\/td>\n1.4462<\/td>\n1.441<\/td>\n<\/tr>\n
PREN<\/td>\n~34\u201336<\/td>\n~42\u201343<\/td>\n<\/tr>\n
Max Chloride Tolerance (approx.)<\/td>\nUp to ~25,000 ppm at <40\u00b0C<\/td>\nUp to ~50,000 ppm at <60\u00b0C<\/td>\n<\/tr>\n
Max Service Temperature<\/td>\n300\u00b0C<\/td>\n280\u00b0C<\/td>\n<\/tr>\n
SCC Resistance<\/td>\nExcellent<\/td>\nSuperior<\/td>\n<\/tr>\n
Pitting Resistance<\/td>\nVery Good<\/td>\nExcellent<\/td>\n<\/tr>\n
Weldability<\/td>\nGood<\/td>\nModerate<\/td>\n<\/tr>\n
Machinability<\/td>\nGood<\/td>\nModerate<\/td>\n<\/tr>\n
Best for<\/td>\nModerate corrosive environments, cost sensitive projects<\/td>\nSevere corrosive environments, critical long life assets<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Duplex 2205 is the widely used for moderate corrosive environments<\/h6>\n

Application of Duplex 2507 vs 2205<\/strong><\/p>\n

Industry applications of Alloy 2205<\/p>\n