Heat treatment timing
Thread Content
This post was last edited by kareale88 on 2019-4-2 at 10:50. When manufacturing containers, it is common to carry out overall heat treatment on the heads and cylinders. Is it determined by experience or are there specific rules regarding when normalizing should be done and when annealing should be done? Where else can this information be found besides 47016? Seeking help from experts
I seek advice from experts regarding the timing for normalizing and returning the material, as well as the rate of temperature change. The specifications are outlined in 47016, but only the minimum temperature required for holding is specified; the exact timing is not indicated!
The material supply status has requirements for heat treatment, such as normalizing, solution treating, and quenching and tempering; these are requirements placed on steel mills. Also, during manufacturing, heat treatment is required in the following situations: for example, from a media perspective, in cases of extremely high hazard, or when stress corrosion is present. From a material perspective, for example, those with a greater thickness, or steels such as Cr-Mo that have higher strength. From a manufacturing perspective, this occurs during the cold working of components, after the components are welded together, or after all components have been assembled and welded. Some can be determined from the design requirements from the start, while others need to be decided based on the actual manufacturing process. The heat treatment process refers to how to raise the temperature, maintain it at that level, and then lower it again – what temperature and for how long. This depends on the specific material; there is plenty of information available on this topic, or various organizations have their own experienced methods. For heat treatment, the effect is what matters.
The basis of heat treatment is the alloy phase diagram, with a focus on changes in metallography. A common practice is post-weld heat treatment, which generally involves heating to below the AC1 temperature in the alloy phase diagram; this can be referred to as annealing. GB150, HG2058X – the six standards all include these requirements
This issue involves many aspects; it is recommended that the original poster first become familiar with the standards and regulations. The types of heat treatment vary, and depending on the purpose of heat treatment, the timing and requirements also differ.
Take GB150 as an example – there are heat treatments for restoring the properties of materials, heat treatments after welding, heat treatments to improve material properties, and heat treatments to restore the material to its condition at the time of delivery, among others
Judgment is made in accordance with GB/T150, HG/T20580~20585 and the corresponding material standards.