Welding of internal components in titanium composite plates
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Experts, for tower equipment made of titanium composite plates, how is the welding of the internal components carried out? (1) Welded directly to the cladding – if the inner component is heavy, could this cause the cladding to peel off? (2) If welding is done on the base layer, why can’t titanium be welded to carbon steel? Additionally, JB/T4745-2002 \"Welded Titanium Vessels\" specifies that the upper limit for the allowable operating temperature of titanium-lined structures is generally 250°C. However, I have seen other companies using titanium lining structures at an operating temperature of 275°C – what is the reason for this? Could an expert please help me understand this?
This post was last edited by chenjdvip on 2019-12-27 at 17:10. The maximum operating temperature for titanium composite plates is 350°C, while the minimum is -296°C. What you mean by a lining structure is probably that all modified equipment should have such a lining structure; for this type of structure, the maximum operating temperature is 250°C. At present, most equipment in China adopts a composite panel structure, with lining structures being used very rarely.
Welding the internal components is not difficult; the main challenge lies in welding the connections
Master, in other words: the lining structure mentioned in the standards refers to the entire device. If the body is a composite plate and the connection flange has a lined structure, what is the upper limit of its operating temperature, 350°C?
Yes, currently, it is difficult with existing industry technologies to use titanium-steel composite steel plates for nozzles; nozzles are basically of a bushing structure, while the cylinder body, end caps, and flange surfaces use composite plate structures.
Thank you, expert, for clarifying this! :handshake
When titanium is used only as a corrosion-resistant layer and does not contribute to strength, the temperature can be increased appropriately; moreover, the allowable temperature for titanium in the ASME material section seems to be 50 degrees higher. Concerns about delamination: shear tests can be conducted at 170 MPa; plates rated B1 for explosion resistance are supplied, and 100% re-inspection is carried out upon arrival of the materials. None of these are the main issues; the key thing is to avoid welding the support beams to the strips. The question you asked is not something that should be given primary consideration in the design and manufacturing of titanium-lined equipment.
We have encountered this problem as well. Internal components need to be suspended on the inner wall of the composite plate cylinder, and it operates under negative pressure. Worried about load-bearing issues, several titanium studs were later made and screwed into the base layer, with their ends sticking out to help bear the load. The load is shifted from being borne solely by the lining shear force to a combination of shear force and the shear force exerted by the process studs. This force is quite strong, and no problems have occurred.