What kind of heat treatment is generally applied to duplex steel?
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What kind of heat treatment is generally applied to duplex steel? Share your opinions.
Generally, heat treatment is not recommended. It’s quite difficult to perform heat treatment on duplex stainless steel. Could the original poster tell us what kind of structure this is and whether heat treatment is necessary?
It depends on what kind of structure it is. Whether heat treatment is required – it’s not easy to carry out heat treatment! :lol It’s best to do it if possible!
If it is duplex stainless steel, it is best not to perform post-weld heat treatment, as it will affect the properties of the steel.
Original poster, I think it’s better to clarify the issue when returning it, because from our actual experience of using it, duplex steel is indeed an excellent material. There are many advantages. However, just as everything has its advantages, it also has its disadvantages. When double-phase steel is welded improperly, phase transformation can occur easily, which accelerates the rate of corrosion; as a result, it is not as useful as ordinary stainless steel. I’ve really never heard of its heat treatment
Generally, austenitic stainless steels require solution treatment; is this necessary for duplex steels? How to do it?
Generally, when welding two types of duplex stainless steels together, no preheating is required before welding, nor is heat treatment necessary after welding. For thicker double-phase steel composite plate vessels that require overall heat treatment, an appropriate heat treatment temperature must be selected. This temperature needs to take into account both the embrittlement temperature of the double-phase stainless steel and the temperature at which the σ-phase forms (for 2205, these are 350–525°C and 700–975°C respectively), as well as the mechanical properties of the carbon steel and low-alloy components. Generally, a temperature in the range of 550–620°C is chosen.
If the deformation amount is large during processing, and solution treatment is required at two sensitization temperatures of 350–525°C and 700–975°C
The degree of deformation is high during the processing; for example, when U-shaped heat exchange tubes are bent and then subjected to solution treatment, it is crucial to ensure that the constant-temperature period is very short – less than 1 minute – followed by rapid cooling
Generally, solution heat treatment is required, and the temperature must be carefully controlled; the treatment time should be kept as short as possible within the sensitization temperature range!
Heat treatment of duplex steel should be avoided if possible; our company has suffered heavy losses as a result of this. In China, this material known as duplex steel has only been manufactured so far. Fundamental theoretical research is still lacking, and accordingly, there is no clear definition for the heat treatment processes at present.