1. Compared with 304 stainless steel, the advantages of duplex stainless steel are as follows:
(1) The yield strength is more than twice that of ordinary austenitic stainless steel, and it has sufficient plastic toughness required for forming. The wall thickness of storage tanks or pressure vessels made of duplex stainless steel is 30-50% lower than that of commonly used austenite, which is beneficial to reducing costs.
(2) It has excellent resistance to stress corrosion cracking. Even duplex stainless steel with alloy content has a higher resistance to stress corrosion cracking than austenitic stainless steel, especially in environments containing chloride ions. Stress corrosion is a prominent problem that is difficult to solve for ordinary austenitic stainless steel.
(3) The corrosion resistance of 2205 duplex stainless steel, which is the most commonly used in many media, is better than that of ordinary 316L austenitic stainless steel, while super duplex stainless steel has extremely high corrosion resistance. Some media, such as acetic acid, Formic acid, etc. can even replace high-alloy austenitic stainless steel and even corrosion-resistant alloys.
(4) It has good local corrosion resistance. Compared with austenitic stainless steel with the same alloy content, its wear corrosion resistance and fatigue corrosion resistance are better than austenitic stainless steel.
(5) The linear expansion coefficient is lower than that of austenitic stainless steel and close to that of carbon steel. It is suitable for connection with carbon steel and has important engineering significance, such as the production of composite plates or linings.
(6) No matter whether under dynamic or static load conditions, it has a higher energy absorption capacity than austenitic stainless steel. This structural part can cope with unexpected accidents such as collisions, explosions, etc. Duplex stainless steel has obvious advantages and has practical application value.
2. Compared with 304 stainless steel, the disadvantages of duplex stainless steel are as follows:
(1) The universality and versatility of applications are not as good as austenitic stainless steel. For example, its use temperature must be controlled below 250 degrees Celsius.
(2) Its plastic toughness is lower than that of austenitic stainless steel, and its cold and hot processing technology and forming performance are not as good as austenitic stainless steel.
(3) There is a medium-temperature brittle zone, and the process system of heat treatment and welding needs to be strictly controlled to avoid the appearance of harmful phases and damage to performance.
Post time: Dec-20-2023