Is heat treatment required for pressure vessel spliced heads (hot-rolled)?
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The pressure vessel head specifications are φ3000×26; it is fabricated by splicing 2200mm thick plates and undergoing hot forming. The supply material is Q345R, hot-rolled. Container medium: soda mixture. Question: Is heat treatment required for the weld?
It’s not necessary. However, it should be noted that a welding process with normalizing treatment should be chosen for the butt welds.
No need, just do a 100% RT
Should the head be assembled first and then formed, or via hot forming? Is the steel plate in hot-rolled condition, and what kind of heat treatment is required? First, the components are joined together to form the head; in accordance with GB/T25198-2010, RT/UT testing is carried out at 100%, and in accordance with TSG21-2016, MT/PT testing is conducted at 100%.
Yes, it’s because of the normalizing treatment that there are differences in opinions.
Regarding heat treatment, given the thickness of this material, no post-weld heat treatment is required
This post was last edited by bluishice on 2019-10-19 09:35. The delivery condition of the steel plates is hot-rolled; this means that the equipment has no requirements regarding the state of the steel upon delivery, so there is no need to ensure that it is in an normalized state after hot pressing. There is no need to carry out normalizing heat treatment after hot pressing. If the equipment requires normalized steel plates, then the plates themselves must be in a normalized state; it is no longer allowed to purchase hot-rolled plates and then normalize them oneself. For process qualification, it is not necessary to choose quenching and tempering qualification; more strictly speaking, process qualification for post-weld heat treatment can be selected, or it is also possible to opt for no heat treatment.
No heat treatment is required; even for thin-walled heads that have been normalized, as long as the initial pressing temperature is kept below 800 degrees, there is no need to restore their normalized properties； If cold spinning is used, ordinary head manufacturing plants will put the parts into a furnace to eliminate the aforementioned stresses