1) 2205 stainless steel tube yield strength is more than double that of ordinary austenitic stainless steel, and has sufficient plastic toughness required for molding. The thickness of the tank or pressure vessel made of duplex stainless steel is 30-50% lower than that of the commonly used austenite, which is beneficial to reduce the cost.
2) It has excellent resistance to stress corrosion cracking. Even the duplex alloy with the lowest alloy content has higher resistance to stress corrosion cracking than austenitic stainless steel, especially in the environment containing chloride ions. Stress corrosion is a prominent problem that is difficult to solve in ordinary austenitic stainless steels.
3) The most common 2205 duplex stainless steel used in many media has better corrosion resistance than ordinary 316L austenitic stainless steel, while super duplex stainless steel has high corrosion resistance. In some media, such as acetic acid and formic acid. It can even replace high-alloy austenitic stainless steels and even corrosion-resistant alloys.
4) It has good local corrosion resistance, and its wear resistance and fatigue corrosion resistance are better than that of austenitic stainless steel compared with austenitic stainless steel with equivalent alloy content.
5) Compared with austenitic stainless steel, it has a lower coefficient of linear expansion and is close to carbon steel. It is suitable for connection with carbon steel and has important engineering significance, such as producing composite plates or linings.
6) Compared with austenitic stainless steel under dynamic or static load conditions, it has higher energy absorption capacity. This pair of structural parts can cope with unexpected accidents such as collisions and explosions. Duplex stainless steel has obvious advantages and has practical application value.
Compared with austenitic stainless steel, the disadvantages of duplex stainless steel are as follows:
1) The universality and versatility of the application is not as good as that of 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, cold, hot processing and forming properties 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 impair performance.