The Duplex 2205 stainless steel is commonly used in applications that require high corrosion resistance and strength (both ferritic and austenitic). A number of modifications were made to the S31803 stainless steel grade, resulting in UNS S32205, which was endorsed in 1996. This grade is more corrosion-resistant.
These temperatures do not allow this grade of stainless steel to be used because its brittle micro-constituents precipitate at temperatures above 300°C and transition from ductile to brittle beneath -50°C; therefore, they cannot be used for heat treatment.
There are certain properties that may not be uniform across other products such as bars and pipes, as the ones listed below relate to flat rolled products such as plates, sheets, and coils fulfilling ASTM A240 or A240M.
It is a nitrogen-enhancing duplex stainless steel 2205 that was developed to combat corrosion problems common to 300 series stainless steels. The word Duplex describes a family of stainless steels that are neither fully austenitic nor purely ferritic, but neither purely austenitic nor purely ferritic. Duplex 2205 stainless steel consists of austenite pools that are surrounded by a continuous ferrite phase, which is around 40-50% of the steel's total ferrite content when annealed. There are several grades of stainless steels in the duplex family, but the 2205 is the grade most commonly used.
An austenitic-ferritic duplex structure offers both the advantages of a ferritic alloy (high strength and corrosion resistance), and the advantages of an austenitic alloy (easiness of manufacturing).
2205 Duplex stainless steel should only be exposed to temperatures below 600°F. Extended exposure to elevated temperatures can cause it to become brittle.
The Stainless Steel Duplex 2205 is one of the most widely used and versatile stainless steel grades due to its excellent corrosion resistance and high strength. It is widely used in food and beverage industries because of its excellent corrosion resistance. This stainless steel alloy, which is composed of nitrogen-enhanced elements, was developed to combat the corrosion problems commonly encountered with 300 series stainless steels. As Duplex Steel 2205 is susceptible to precipitation of brittle micro-constituents above 300°C, it is generally not recommended for use at temperatures above 300°C, nor below -50°C because of the transition between ductile and brittle 2205 stainless steel properties.
What Are The Characteristics Of Duplex 2205?
- High resistance to chloride stress corrosion cracking is achieved by the design of this product
- The metal can resist pitting and corrosion caused by chlorides and crevice corrosion
- The corrosion resistance of this product is good in general
- Good resistance to corrosion caused by sulfide stress
- This is a high-performance product
- The material is weldable and workable
The corrosion resistance of grade 2205 stainless steel is much higher than the corrosion resistance of grade 316. The CPT of this type of stainless steel is around 35°C, and it resists localised corrosion types such as intergranular, crevice, and pitting. It is resistant to chloride stress corrosion cracking (SCC) at temperatures of 150°C. In environments that are susceptible to premature failure and marine environments, grade 2205 stainless steels are ideal replacements for austenitic grades.
This grade has high resistance to oxidation, but the high oxidation resistance is compromised by its embrittlement above 300°C. This embrittlement is easily modified by annealing the ductile iron at a temperature below 300°C. This grade is good in low-temperature conditions.
For the best temperature hardening results, grade 2205 must undergo a solution treatment (annealing) between 1020 and 1100 degrees Celsius, followed by rapid cooling. This grade can be work-hardened by means of work hardening, but it cannot be hardened by means of heat treatment.
Generally speaking, the majority of standard welding methods are suitable for the welding of 2205, with the exception of welding without filler metals, which results in excessive ferrite. AS 1554.6 pre-qualified welding for 2205 using 2209 rods or electrodes, so that the deposited metal can have a balanced duplex structure.
This type of shielding gas, in combination with nitrogen, ensures that adequate austenite is added to the structure. During the process of completing the shielding gas, heat input should be kept low, and pre and post-heat should not be used. This grade has a low coefficient of thermal expansion, which reduces the distortions and stresses that are encountered with austenite.
Processing – Hot Forming:
Duplex 2205 density is a steel that can be formed by using hot-forming techniques at temperatures between 2009 and 2100°F (1100 and 1150°C). However, if a workpiece is not compact, the edge temperature may be significantly lower than the bulk temperature, resulting in cracking along the cooler areas of the workpiece.
Processing – Cold Forming:
The high strength of Duplex 2205 makes it suitable for fabrication in a wide range of applications, but the dense structure of the material can pose problems in forming. Even with sufficient power, the grade's high strength entails a higher spring-back.
Due to its high strength, the machinability of this grade is poor. The cutting speeds are nearly 20% slower than that of grade 304.
A grade of this type can also be fabricated with a lot of strength because it has a lot of ductilities, therefore cold heading is not possible on this grade. The ductility of grade 2205 is not as high as austenitic grades, so it will need equipment with a large capacity for bending and forming. A cold heading operation on this grade requires intermediate annealing in order for it to be successful.
This list is comprised of some of the most common applications of duplex steel grade 2205, including:
- Exploration and production of oil and gas
- Equipment that is used for processing
- The transportation, storage, and processing of chemicals
- Environments with high chloride levels and marine environments
- The companies that we work with manufacture a wide range of paper machines, liquor tanks, pulp and paper digesters, etc.