Alloy 2205

Introduction

Duplex Steel 2205 is used extensively in applications that require good corrosion resistance and strength. The S31803 grade stainless steel has undergone a number of modifications resulting in UNS S32205, and was endorsed in the year 1996. This grade offers higher resistance to corrosion. At temperatures above 300°C, the brittle micro-constituents of this grade undergo precipitation, and at temperatures below -50°C the micro-constituents undergo ductile-to-brittle transition; hence this grade of stainless steel is not suitable for use at these temperatures.

Equivalent Grades Of Alloy 2205

Zeon Grade Alloy Name UNS EN / DIN / W Nr. AISI / ASTM Trademarks
Zeon51 Alloy 2205 UNS S31803 1.4462 F51 SAF 2205
Zeon60 Alloy 2205 UNS S32205 1.4462 F60 SANMAC 2205/URANUS45N

Chemical Composition Of Alloy 2205

Grade   C Mn Si P S Cr Mo Ni N
2205 (S31803) Min - - - - - 21.0 2.5 4.5 0.0
Max 0.030 2.00 1.00 0.030 0.020 23.0 3.5 6.5 0.20
2205 (S32205) Min - - - - - 22.0 3.0 4.5 0.14
Max 0.030 2.00 1.00 0.030 0.020 23.0 3.5 6.5 0.20

Physical Properties Of Alloy 2205

Grade Density (kg/m3) Elastic Modulus (GPa) Mean Co-eff of Thermal Expansion (μm/m/°C) Thermal Conductivity (W/m.K) Specific
Heat
0-100°C (J/kg.K)		 Electrical
Resistivity
(nΩ.m)
0-100°C 0-315°C 0-538°C at 100°C at 500°C
2205 782 190 13.7 14.2 - 19 - 19 850

Mechanical Properties Of Alloy 2205

Grade Tensile Str
(MPa) min		 Yield Strength 0.2% Proof (MPa) min Elongation (% in 50mm) min Hardness
Rockwell C (HR C) Brinell (HB)
2205 621 448 25 31 max 293 max
Corrosion Resistance Properties of Alloy 2205
Grade 2205 stainless steel exhibits excellent corrosion resistance, much higher than that of grade 316. It resists localized corrosion types like intergranular, crevice and pitting. The CPT of this type of stainless steel is around 35°C. This grade is resistant to chloride stress corrosion cracking (SCC) at temperatures of 150°C. Grade 2205 stainless steels are apt replacements to austenitic grades, especially in premature failure environments and marine environments.
Heat Resistance Properties of Alloy 2205
The high oxidation resistance property of Grade 2205 is marred by its embrittlement above 300°C. This embrittlement can be modified by a full solution annealing treatment. This grade performs well at temperatures below 300°C.

Processing Alloy 2205

Heat Treatment The best suited heat treatment for this grade is solution treatment (annealing), between 1020 - 1100°C, followed by rapid cooling. Grade 2205 can be work hardened but cannot be hardened by thermal methods.
Welding Most standard welding methods suit this grade, except welding without filler metals, which results in excess ferrite.
Machinability The machinability of grade 2205 is low due to its high strength. The cutting speeds are almost 20% lower than that of grade 304.
Fabrication The fabrication of grade 2205 is also affected by its strength. Bending and forming of this grade requires equipment with larger capacity. Ductility of grade 2205 is lesser than austenitic grades; therefore, cold heading is not possible on this grade. In order to carry out cold heading operations on this grade, intermediate annealing should be carried out.
Applications Of Alloy 2205
Oil and gas exploration Processing equipment. Transportation & storage of chemicals. High chloride and marine environments Paper machines, tdquor tanks, pulp and paper digesters