Titanium is prone to crevice corrosion in some media

Since titanium also has a creep phenomenon at room temperature, the problem of stress relaxation occurs. When selecting titanium bolts, it is best not to use titanium bolts as a forcibly sealed connection. When titanium bolts are required for corrosion resistance, the structural design needs to consider the ease of tightening the bolts regularly to ensure sealing. Titanium, like stainless steel, also has friction bonding and seizure phenomena. The adjustment and action performance of the titanium valve are controlled by the valve stem thread, which is achieved by the rotation of the handwheel and should be guaranteed by the material properties and the manufacturability of each part. Titanium threads are easy to bite, which can be solved with dissimilar materials or threads with larger clearances or with appropriate lubricants. The internal thread that needs to be tapped should be used less, and the turning thread structure with undercut groove should be used as much as possible. It can be cut by general cutting methods, due to the high chemical activity and special physical and mechanical properties of titanium rods and titanium alloys. However, compared with other commonly used metals, there are also special requirements. Master certain processing techniques and pay attention to them during processing. In order to use titanium material economically and rationally, grade 5 titanium round rod is more expensive. Parts made of titanium should not be used as much as possible for parts that are not in contact with corrosive media.

Titanium is prone to crevice corrosion in some media. Structural design should minimize gaps and recesses where water can be stored. The gap between the titanium plate and the titanium plate is also susceptible to corrosion, especially the gap formed by titanium and tetrafluoride. Because titanium is not resistant to solutions containing small amounts of soluble fluoride, fluoride causes passive damage. Therefore, special care should be taken when using PTFE plastic gaskets, fluorine-containing rubber gaskets and adhesives. Its strength index decreases with increasing temperature, and the mechanical properties of titanium change with temperature. For example, the tensile strength and yield strength at 250 to 300 °C are half of those at normal temperature. Even when the design temperature is not high, so. It should also be selected according to the strength value at the design temperature. Titanium has a high yield-to-strength ratio and good durability. When the design temperature is below 316 °C, the tensile strength value at this temperature is often determined by the design strength index. For industrial pure titanium, when the strength index value cannot be improved by heat treatment, when titanium is used in combination with other materials, the thermal expansion coefficient of titanium is small. Pay attention to the stress caused by the differential expansion.