1. Compared with 304 stainless steel pipe, the advantages of duplex stainless steel are as follows:
(1) The yield strength is more than double that of ordinary austenitic stainless steel, and it has sufficient plasticity and toughness required for forming. The wall thickness of storage tanks or pressure vessels made of duplex stainless steel is 30-50% less than that of commonly used austenite, which is beneficial to reduce 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 an outstanding 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, and super duplex stainless steel has extremely high corrosion resistance. In some media, such as acetic acid, Formic acid 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 equivalent alloy content, its wear resistance and fatigue corrosion resistance are better than austenitic stainless steel.
(5) The coefficient of linear expansion is lower than that of austenitic stainless steel, which is 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 under the condition of dynamic load or static load, it has higher energy absorption capacity than austenitic stainless steel, which has obvious advantages and practical application value for structural parts to deal with unexpected accidents such as collisions and explosions.
2. Compared with 304 stainless steel, the disadvantages of duplex stainless steel are as follows:
(1) The universality and versatility of the application are not as good as austenitic stainless steel, for example, its service 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 formability are not as good as austenitic stainless steel.
(3) There is a medium-temperature brittle zone, and it is necessary to strictly control the heat treatment and welding process system to avoid the appearance of harmful phases and damage performance.
Post time: Mar-16-2023