Performance and characteristics of commonly used duplex stainless steel - B2205

This article is translated from RandyXu Industrial Technology Society

1. Overview

Duplex stainless steel 2205 is a duplex stainless steel composed of austenitic stainless steel and ferritic stainless steel, which exhibits excellent corrosion resistance and mechanical properties. Its yield strength is twice that of 300 series stainless steel, making it widely used in industries such as oil and gas, petrochemicals, bridges, seawater desalination, and chemical tankers.

2. Chemical composition

3. Mechanical properties

4. Corrosion resistance

A constant load tensile test for sulfide stress corrosion cracking resistance was conducted on 2205 steel plates, following the standard GB/T4157-2006, and with reference to the American Society of Corrosion Engineers' NACE TM0177-1996

5. Characteristics of duplex stainless steel 2205

advantage

(1) The yield strength of 2205 duplex stainless steel is more than twice that of austenitic stainless steel, and it possesses sufficient ductility and toughness for forming. The wall thickness of pressure vessels made of 2205 duplex stainless steel can be reduced by 30-50% compared to 316L stainless steel, which is beneficial for cost reduction.

(2) 2205 duplex stainless steel exhibits excellent resistance to stress corrosion cracking, especially in marine environments containing chloride ions. Stress corrosion is a prominent and difficult problem for austenitic stainless steels, including 316L stainless steel.

(3) The linear expansion coefficient of 2205 duplex stainless steel is lower than that of 316L stainless steel, yet it is close to that of carbon steel, making it suitable for connecting with carbon steel and thus of significant engineering importance.

(4) Whether under dynamic or static loading conditions, 2205 duplex stainless steel exhibits higher energy absorption capacity compared to austenitic stainless steel. This provides significant advantages and practical application value for structural components or pipelines in dealing with sudden events such as collisions and explosions.

Everything and every substance in the world has its dual nature. It has its strengths, and inevitably, there are areas where it excels less. Just like duplex stainless steel, despite its numerous advantages, it also has its shortcomings.

shortcomings

(1) The universality and versatility of applications are not as good as those of austenitic stainless steel, for example, its use temperature must be controlled below 250℃.

(2) 2205 duplex stainless steel exhibits mid-temperature brittleness, necessitating strict control over the heat treatment and welding processes to prevent the emergence of harmful phases that could compromise its performance.

The main reason for the inferior performance of duplex stainless steel compared to austenitic stainless steel is due to the large amount of ferrite structure present in duplex stainless steel.