On heat treatment of fatigued equipment
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Standard JB4732-1995 does not require fatigue-resistant equipment to undergo stress-relief heat treatment, but its explanatory notes do require it; I’m not sure what to do in this situation
I hadn’t noticed this yet. But I think we should take into account factors such as media and materials
The fatigue-resistant containers we produce require heat treatment in terms of their material, thickness, the medium they are used with, and other factors; we have never encountered a case where heat treatment is not necessary. Could the original poster explain what kind of fatigue container it is?
Specific heat treatment requirements are specified in clause 10.4.1 of JB4732; these requirements are similar to those in clause 10.4 of GB150, with slight differences, which can be referred to for comparison*
There are various situations related to fatigue-prone equipment. What I’m emphasizing here is fatigue; other factors such as material properties, thickness, or the need for heat treatment due to the medium in use are considerations of a different nature. The molecular sieve dryers we produce have a thickness of 28 mm, are made of Q345R material, and use natural gas as the medium – according to the relevant standards, heat treatment is not required in this case.
If it is not made of stainless steel, it is recommended to carry out stress-relief heat treatment, as this is more beneficial for fatigue resistance.
I remember the expert clearly explaining during the lecture that since stress-relief heat treatment only reduces the absolute value of stress without decreasing the amplitude of alternating stress, standards do not require heat treatment for fatigue-prone components; however, I cannot find any written evidence for this.