Compared with the austenitic stainless steel, duplex stainless steel of the vulnerable is as follows:
1 The application of universal and multi-faceted as stainless steel, such as its temperature must be controlled at 250 degrees Celsius.
2 The plasticity and toughness lower than the austenitic stainless steel, cold, heat processing process and molding properties than austenitic stainless steel.
3 The existence of temperature brittle zone, the need for strict control of heat treatment and welding technology system in order to avoid the appearance of harmful phase, damage to property.
Compared with the ferritic stainless steel, duplex stainless steel strengths are as follows:
1 the mechanical properties of ferritic stainless steel than good, especially the plastic toughness ferritic stainless steel is not as brittle as sensitive.
2 In addition to resistance to stress corrosion, other localized corrosion resistance is superior to ferritic stainless steel.
3 cold and cold-forming properties of process performance is much better than ferritic stainless steel.
4 welding performance is far superior to ferritic stainless steel, the former general welding without preheating, without heat treatment after welding.
5 scope of application than the width of ferritic stainless steel.
Compared with the austenitic stainless steel, duplex stainless steel strengths are as follows:
1 Yield strength than conventional austenitic stainless steel more than twice as high, and has a plastic molding needs adequate toughness. Use of duplex stainless steel tank or pressure vessel wall thickness less than the usual 30-50% austenite is beneficial to reduce costs.
2 Duplex stainless steel has excellent resistance to stress corrosion cracking capacity, even with the lowest amount of duplex stainless steel alloy has a higher resistance than the austenitic stainless steel stress corrosion cracking capacity, especially in chloride ion environments. Austenitic stainless steel stress corrosion is a common problem difficult to resolve outstanding.
3 In many applications the most common medium of 2205 duplex stainless steel corrosion resistance than the average of316L stainless stee, and super duplex stainless steel with high corrosion resistance, then a number of media, such as acetic acid, formic acid, etc. can even replace the high-alloy austenitic stainless steel, and even corrosion resistant alloy.
4 Duplex stainless steel has a good resistance to localized corrosion, with the austenitic stainless steel alloy content rather than its resistance to corrosion and fatigue corrosion and wear better than the austenitic stainless steel.
5 The linear expansion coefficient of austenitic stainless steel is low, and carbon steel close fit with the carbon steelconnections, has important engineering significance, such as the production of composite boards or lining and so on.
6 in terms of dynamic load or static load conditions, the ratio of austenitic stainless steel has a higher energy absorption capacity, which structural parts to cope with sudden incidents such as collisions, explosions, etc., have obvious advantages of duplex stainless steel, are of practical value .
Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)
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