Titanium bellows have properties suitable for manufacturing bellows such as working temperature, cyclic stress resistance, and corrosion resistance. However, titanium has poor formability due to its high work hardening rate and poor plastic deformation ability. This makes the production of titanium bellows very difficult. Titanium is also active chemically and can react with elements like carbon, hydrogen, nitrogen and oxygen at high temperatures, making the material brittle. For these reasons, only a small number of studies have reported the production and use of titanium bellows so far.

1. Titanium Bellows
Bellows is widely used in elastic elements, the material used mainly
metal and non-metallic two categories. Commonly used metal materials
include austenitic stainless steel, corrosion resistant alloys and high
temperature (nickel) alloys.
In chemical equipment, bellows and other connections not only to bear a
certain load, but also by the strong corrosion of many media, working
conditions are very harsh. Titanium instead of stainless steel, nickel-based
alloys and other rare metals as corrosion-resistant materials, which extend

2. the service life and safety of equipment and so on are very important. The
properties of titanium materials such as working temperature, cyclic
stress, corrosion resistance and processability are suitable for the
manufacture of bellows, but the cold deformation resistance of titanium is
large, the rebound is serious, the plastic deformation ability is poor, the
welding performance is poor, Difficult, high scrap rate, high cost, so far,
only a small amount of literature reported the production and use of
titanium bellows.

3. Ti Classification

4. &Characteristics
Titanium is divided into industrial pure titanium and titanium alloy,
domestic industrial titanium TA0, TA1, TA2, TA3, etc., foreign brands are
the United States SB265Gr11, Gr12, Gr13, the difference is that the
content of different oxygen and nitrogen impurities, These impurities
make industrial pure titanium reinforced, but the plasticity is significantly
reduced, TA2 chemical composition, mechanical properties and process
performance in Table 1. Titanium is a very active chemical nature of the
metal, at high temperatures with many elements (carbon, hydrogen,
nitrogen, oxygen, etc.) and the reaction of the compound, making the
material brittle, So titanium is used for operating conditions below
350 ℃.
Titanium density of 4151g / cm3, higher than aluminum and lower than
steel, copper, nickel, its strength is located in the first metal. The tensile

5. strength of titanium is close to its yield strength. The properties of
titanium show that the yield strength (yield strength / tensile strength) is
high, which indicates that the plastic deformation of titanium is poor
during forming, and the forming of bellows is very difficult. Titanium
elastic modulus is very low, at room temperature for 10614GPa, 57% of
steel, titanium yield limit and modulus of elasticity ratio, so that the
resilience of titanium molding.
Titanium Stability
Titanium is stable in many media, such as titanium in the oxidation,
neutral and weak reductive and other media is corrosion-resistant. This is
because titanium and oxygen have a great affinity in the air or
oxygen-containing medium, the titanium surface to generate a layer of
dense,This is because titanium and oxygen have a great affinity, in the air
or oxygen-containing medium, the titanium surface to produce a layer of
dense, strong adhesion, inert oxide film to protect the titanium matrix is
not corrosive.

6. Corrosion
Resistance
Even if the mechanical wear will soon be self-healing or re-regeneration.
This indicates that titanium is a metal with a strong passivation tendency.
The dielectric film temperature of 315℃below the titanium oxide film

7. always maintain this feature. Because titanium has good corrosion
resistance, so more for the chemical industry, the oil industry.
Note:
1. Corrosion resistance is divided into three levels:
优良- corrosion resistance, corrosion rate of 0.127mm / a below.
良好- medium corrosion resistance, corrosion rate between 0.127-1.27mm / a.
差- no corrosion resistance, corrosion rate of 1.27mm / a or more.
2. Pure titanium has high corrosion resistance in most media, especially in neutral,
oxidizing media and seawater. Titanium in seawater corrosion resistance than aluminum,
stainless steel and nickel alloy is also high, in the industrial, agricultural and marine
environment in the atmosphere, although the years, the surface does not change color.
Hydrofluoric acid, sulfuric acid, hydrochloric acid, orthophosphoric acid and some hot
concentrated organic acids on the corrosion of titanium (see above), which hydrofluoric acid
regardless of concentration, temperature, the titanium has a high corrosion. Titanium on
various concentrations of nitric acid and chromic acid stability, in alkaline solution and most
organic acids, inorganic salt solution corrosion resistance is also high.