Does such a container require heat treatment?
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This post was last edited by zjq1962 on 2018-6-22 at 15:39. There is a container made of titanium composite material; the medium inside the inner cylinder is highly toxic. The base material used is Q345R, and heat treatment is required in accordance with GB/T150. Is heat treatment also necessary for titanium pressure vessels? How should we understand the text in parentheses in the figure? I understand that first, it involves all-titanium equipment; when the medium poses a significant risk of stress corrosion cracking in titanium, heat treatment is required ； The second case is composite plate containers; when the base material requires heat treatment, such treatment must be carried out. Under this understanding, this device requires heat treatment.
I believe that for titanium composite plate equipment, since the surface in contact with the flow is made of titanium, and titanium does not suffer from stress corrosion in this medium (otherwise titanium would not have been chosen for this purpose), no heat treatment is necessary as long as the thickness of the base layer is below the threshold required for such treatment.
This post was last edited by zjq1962 on 2018-6-22 at 16:47. Is this related to whether the medium is in contact with the base material? The base material is subjected to the pressure and temperature of the equipment, so the manufacturing requirements are formulated with regard to this base material. Regarding the requirement for heat treatment for highly hazardous media, the standard is based not on the corrosive effect of the media on materials, but rather on the degree of hazard posed by the media themselves. I believe the notion that heat treatment is not necessary if the base material does not come into contact with the medium is incorrect.
There is no theoretical basis for heat treatment of carbon steel and low-alloy steel containers used to hold extremely hazardous media in large quantities. Decide for yourself.
This post was last edited by zjq1962 on 2018-6-22 at 16:54. Although there is no theoretical basis for it, standards specify whether compliance is required; can a design pass if those standards are not followed? There is no doubt that heat treatment is required for carbon steel and low-alloy steel vessels; what is discussed here is the case of composite plates.
The main material is titanium-based equipment; if the medium exhibits a significant tendency for stress corrosion cracking in titanium, heat treatment is required, otherwise no heat treatment is necessary； For containers made of titanium composite plates, it depends mainly on whether the base material needs to be heat-treated; if the base material is required to be heat-treated in accordance with GB/T150, then heat treatment must be carried out.
Agreed; I think it should also be heat-treated.