Differences Between Stainless Steel 304 Versus Duplex Steel 2205

The branding power of stainless steel is colossal. Its potential can be determined by its name itself. The corrosion resistance exhibition is due to 12% chromium with other amalgamations. The five main classes of stainless steel alloys are austenitic, ferritic, martensitic, duplex and precipitation-hardening.
The austenitic stainless steel is commonly used in many industries. Duplex stainless steel is combination of almost equal proportion of austenitic and ferritic stainless steel and forms duplex microstructure. Grade 2205 is duplex stainless steel and offers combined properties.
Duplex stainless steel exhibits its superior properties and widely used in oil and gas industry, chemical industries etc. grade 2205 is generally used grade of duplex stainless steel.

Grade 304

Grade 304 is most commercial grade of austenitic stainless steel. It offers great corrosion resistance with high endurance of extreme temperature. The mechanical parameters, formability, weldability are considered and used in many practical applications.

Grade 2205

Grade 2205 has unique properties of austenitic and ferritic in its microstructure. It chemistry comprises of high chromium and molybdenum and proves to be an excellent corrosion resistant material. Grade 2205 offers superlative corrosion resistance with high mechanical properties. It is resistant to stress corrosion cracking and pose high strength.

Difference between grade 304 and 2205 stainless steel

The very basic difference between the two is grade 304 is austenitic stainless steel, whereas grade 2205 is duplex stainless steel. The chemical, physical and mechanical properties of grade 2205 are quite superior to grade 304.
• Grade 2205 pose double yield strength than grade 304
• Fatigue stress is good in case of grade 2205, than grade 304
• Grade 2205 proffers extremely superior resistance to cracking, crevice, pitting and general corrosive mediums.
• Products designs and applications are offered more to grade 2205.

But there are few more points which shows advantages for austenitic stainless steel,
• Austenitic stainless has universal facet applications. It is workhorse of stainless steel industry.
• The plastic toughness for duplex steel is lower than austenitic stainless steel. It is not advised to use above 300° C and below -50C°.
• Duplex stainless steel is pricey than austenitic. Although it is an excellent material, but should be wisely choose.

Chemical Composition

Grade Carbon
(max)% Manganese
(max)% Silicon
(max)% Phosphorus
(max)% Sulfur
(max)% Chromium
(max)% Nickel
(max)% Nitrogen
(max)% Molybdenum
304 0.08 2.0 0.75 0.045 0.030 18-20 8-10 0.10 –
2205 0.030 2.0 0.030 0.030 0.020 21-23% 4.5-6.5 0.08-0.20 2.5-3.5

Mechanical Properties

The grade 2205 shows better tensile and yield strength than grade 304. Also, duplex stainless steel produces better thermal conductivity than austenitic stainless steel

Mechanical properties Grade 2205 Grade 304

Tensile strength 700 Mpa 515Mpa
Proof strength0.2% 570 Mpa 205Mpa
Hardness Brinell (max) 290 200
Elongation 25% 40%


Grade 2205 is used in following industries and equipment:
• Oil and gas industry
• Marine industry- Equipment used in high chloride environments
• Paper and pulp industry

Grade 304 is extensively used in numerous industry and applications like food processing industries, Domestic and commercial kitchenware and appliances ETC.

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