What are the technical requirements of titanium tubes?

Titanium tube has lightweight, high strength and superior mechanical properties. It is widely used in heat exchange equipment, such as tube and tube heat exchangers, coil tube heat exchangers, titanium heat exchanger tube, condensers, evaporators and conveying pipes. Many nuclear power industries regard titanium tubes as standard tubes for their units.
skills requirement:
1. The chemical composition of titanium and titanium alloy tube shall comply with the provisions of GB / T3620.1. When the buyer retests, the allowable deviation of the chemical composition of shall comply with the provisions of GB / T3620.2.
2. The allowable deviation of the outer diameter of the pipe shall comply with the provisions of Table 1.
3. The allowable deviation of the pipe wall thickness should not exceed ± 12.5% ​​of its nominal wall thickness. The allowable deviation of the pipe wall thickness does not apply to the weld of the titanium welded pipe.
4. The length of the pipe should meet the requirements of Table 2.
5. The length of the fixed-length or double length of the pipe should be within its indefinite length. The allowable deviation of the fixed-length is + 10mm. The length of the double-length should also be included in the cut amount when the pipe is cut. .

What are the technical requirements of titanium rods?

Grade 23 Titanium Rod has good physical and chemical properties, low density, lightweight, non-magnetic, high strength, and good corrosion resistance. They have good mechanical properties and welding performance. medical titanium rod is widely used in chemical equipment and seawater. Desalination, marine parts, electroplating industry, etc. Titanium is 10 times more corrosion resistant than ordinary stainless steel, and titanium metal is a metal with relatively low body rejection, so the processed parts of titanium rectangular rod are widely used in human implants and medical devices use.
skills requirement:
1. The chemical composition of titanium and titanium alloy bars shall comply with the provisions of GB / T 3620.1, and the tolerance deviation of the chemical composition shall comply with the provisions of GB / T 3620.2 when the buyer re-inspects.
2. The diameter or side length of the hot-processed bar and its allowable deviation should meet the requirements of Table 1.
3. After hot working, the diameter of the cold-drawn bar and the cold-rolled bar and cold-rolled bar should be in accordance with the requirements of Table 2.
4. The out-of-roundness of the bar after turning (grinding) after hot processing should be no more than half of its dimensional tolerance.
5. The length of the indeterminate length of the processed bar is 300-6000mm, and the length of the annealed bar is 300-2000mm. The length of the fixed-length or double-length should be within the range of the indefinite length.

How does the shrinkage behavior of titanium threaded tube change?

Titanium tubes are similar to other metals. The shrinkage behavior of titanium tubes during casting also undergoes a change from the liquid state to solid state to solid-state. This shrinkage behavior is usually divided into body shrinkage and linear shrinkage. The body shrinkage reflects the change in the entire volume of the titanium exhaust tube during the casting process. Since the total body shrinkage is equal to the volume of the concentrated shrinkage holes of the casting plus the volume of shrinkage, the solidification shrinkage behavior of the alloy casting process is related to the body shrinkage of the alloy The characteristics of shrinkage and shrinkage defects of drill alloys are determined, which are of great significance for understanding the formation of shrinkage and shrinkage defects of Grade 23 Titanium Tube.
The important factors that affect the solidification and shrinkage of titanium tubes include alloy elements, mold materials, and mold structures. Since alloying elements affect the crystallization temperature interval of the titanium tube, just as it affects the fluidity, the solidification shrinkage of the titanium tube first depends on the characteristics of the added alloying element, that is, the crystallization temperature formed between the titanium and the alloying element The size of the interval is related. The eutectic Titanium Coil Tube with a narrow crystallization temperature interval has good fluidity and is easy to form concentrated shrinkage pores, while the titanium tube with wide crystallization temperature interval is poor in fluidity and easy to form dispersed shrinkage pores, ie shrinkage.
Because titanium tubes have a series of good physical properties, as an excellent structural material, it can compete with stainless steel and nickel alloys for the scope of application: in many sectors of the national economy, the use of titanium tubes has increased product life and improved The reliability and productivity of the equipment have accelerated the process and improved working conditions, all of which have achieved significant economic benefits.

Titanium pipe joint welding requirements

Welding personnel should wear clean work clothes, and there should be no oil stains. Welding gloves should use white fine gauze gloves. It is strictly forbidden to wear gloves made of cotton thread and other fabrics.
The materials of the welding platform layout and the wire brushes used for decontamination of the welding area of ​​the welded head should be made of stainless steel. It is strictly prohibited to use carbon steel and other contaminated materials.
The welding site should be set up indoors or in dedicated welding workshops as much as possible. Smoking is strictly prohibited indoors. The environment should be kept clean and dry. The room temperature should not be lower than 5 ° C. Air convection should be strictly controlled.
In order to obtain a better welding quality, the end of the butt joint is processed into a V-shaped groove as much as possible, and the welding area and the surface of the welding wire should be degreased with acetone.
titanium square tube      Grade 5 Titanium Tube     Gr12 Titanium Tube

What are the basic common sense about titanium

Titanium is an uncommon metal, but it is not to say that there is less titanium. In fact, there is not a lot of titanium. Below is some basic common knowledge about titanium. We can summarize it as follows:

Thermal conductivity of titanium:

It is said that the thermal conductivity of metals is fast, titanium is a metal, and the thermal conductivity is naturally not slow, but relatively slower than some of our common metals. From the current data, the thermal conductivity of titanium is closer to stainless steel It is about one-fourth of aluminum and about one-fifth of iron.

Titanium hardness:

Everyone may think that the purer the titanium metal, the greater its hardness. In fact, the hardness of titanium is not large, just right. Some titanium that is not very pure is surprisingly high in hardness, and some impurities can increase its hardness.

Titanium is a rare metal:

The reason for this idea is that the stability of titanium is too good, it is difficult to develop and smelt, and even use it, so it is natural that everyone will think so. In fact, titanium reserves account for 0.6% of the region, Occupying the ninth place, the reserves are very large.

Titanium has a lower mass than aluminum:

In fact, the density of titanium is greater than that of aluminum, but the quality of titanium is much smaller than that of aluminum. The ductility of aluminum cannot be compared with that of titanium.

Titanium has very low activity:

Titanium's low activity depends on the situation. Titanium is very stable in normal temperature air and is not prone to any reaction, but it is very chemically active at high temperatures and can easily react with many gases.

Grade 1 Titanium Plate        Gr12 Titanium Plate       grade 5 titanium plate

Rolling of titanium bars for empty use

The heating characteristics and hot rolling characteristics of die forging blades and bars for manufacturing fasteners. The batch materials used in the former Soviet Union for the manufacture of aerospace blades are titanium round bar such as BT3-1, BT8, BT9 and OT4 with a diameter of 10-60 mm. The material for aviation fasteners is generally BT16 titanium alloy rod with a diameter of 4.0-16mm.
The heating characteristics and hot rolling characteristics of BT3-1, BT8, BT9, and OT4 alloys determine the requirements for bar quality. For example, when hot rolling at the ot + p phase temperature of the alloy, if its deformation is not less than 40% -50%, then the plasticity and fatigue strength indexes of this material are the highest. However, rolling at this temperature can significantly increase the deformation resistance of the blank pass and the intermediate pass, increase the unit pressure, and overload the rolling mill motor.
In this case, the rolling process should be carried out in two stages:
(1) Pre-milk at a temperature higher than a + p-P transition;
(2) Rolled to the finished size at the temperature of the ot + P phase zone of the alloy. In the final rolling stage, the rolled material should be cooled to a temperature below 650T.
Bars with a diameter greater than 8.0mm and rebars with a diameter of 4.0-8.0mm should be rolled under one heat.

How to avoid defects in welding

Titanium and its alloys have a strong chemical activity. When the temperature exceeds 400 ℃, it begins to react with oxygen, nitrogen, hydrogen and carbon. Above 600 ℃, the reaction is violent. Analysis of the increase in oxygen, nitrogen, hydrogen and carbon content will lead to the embrittlement of titanium and its alloy weld metal, so the gas protection of TA2 titanium tube welding is a key issue while controlling the temperature of the weld and heat-affected zone, Avoid generating coarse grains and overheated structures due to overheating, resulting in a reduction in the mechanical properties of the metal. Welding defects that are prone to welding :

1. Crack problem. When welding titanium-based materials, due to the small amount of sulfur and phosphorus impurities in the material, hot cracks rarely occur; however, cold cracks and delays are likely to occur when welding titanium materials. Mainly due to the poor thermal conductivity of titanium, the heat loss is slow, and the grains of the weld are prone to appear; when the gas impurity content is high, the plasticity of the welded joint decreases, especially when more hydrogen is dissolved in the weld Hydrogen embrittlement.

2. Gas protection. Due to the high gas purity requirements when welding titanium, we choose 99.999% high-purity argon; the range of argon to be protected is the base metal of the molten pool, the heat affected area, and the 10mm area outside the fusion line on both sides. For this purpose, special gas protection devices need to be developed; the inside of the pipeline is protected by an argon gas chamber device.

3. Stomata problem. When welding titanium and its alloys, it is often found that after the welding seam RT, there are aggregated pores near the fusion line. The pores are mainly hydrogen pores; as the solubility of hydrogen in titanium decreases with increasing temperature, the high temperature near the fusion line during welding will cause hydrogen to dissolve out. If the hydrogen partial pressure in the atmosphere around the welding zone is high, the hydrogen in the molten metal is not easily precipitated, so it gathers to form hydrogen gas pores.

After welding is completed, the quality of the weld seam is mainly judged by the appearance color of the weld seam. The color of the weld seam is directly related to the protection of argon gas and the cleanliness of the breach. If the titanium pipe appears blue during the welding process Color or bluish-purple should stop welding immediately, find the reason and improve the welding measures in time; if the surface of the welding seam appears dark gray, it should immediately stop welding for repair, remove all dark gray pants, and re-weld.

   Gr7 Titanium Bar     Grade 9 Titanium Plate      bending titanium tubing