Advantages of hot die forging and conventional forging of titanium alloys

Like isothermal forging, hot die forging of titanium alloy processing technology is also a promising precision forging process. The difference is that the mold temperature of hot die forging is higher than that of ordinary forging, but lower than that of isothermal forging. Typical hot die forging die temperature is 110-225°C lower than the billet temperature. Compared with isothermal forging, the reduction of mold temperature can make a wider selection of mold materials, but the ability to form very thin and complex-shaped forgings is slightly worse.

Compared with conventional titanium alloy flange, hot die forging has the following advantages:

(1) Reduce the material consumption of forgings. During hot die forging, the chilling of the die contacting the blank and the work hardening of the material are reduced, and the forgeability of the material is improved, so the forgings are allowed to have a smaller fillet radius and a smaller draft The inclination and small forging allowance greatly reduce the quality of forgings. For example, a Ti-6Al-4V alloy structural part has a mass of 28kg. The mass of forging produced by conventional forging process is 154kg, while the mass of forging produced by hot die forging process is 109kg. The difference between the two methods is 45kg.

(2) Reduce the number of forging operations and improve the working capacity of the press. During hot die forging, the mold temperature is higher and the temperature drop of the billet is less. Conventional forging requires two fires, three fires or more fires to form forgings. Hot die forging Only one time, as many as two fires can be completed. And because of hot die forging, the deformation resistance of the metal is low, which relatively increases the working capacity of the equipment.

(3) Reduce the amount of machining of forgings Because the forgings produced are close to the weight and contour size of the parts, compared with the forgings produced by conventional forging, the amount of material removal in machining is reduced.

(4) The uniformity of the product is better. During the forging process, the temperature gradient is greatly reduced, and the uneven deformation caused by the temperature gradient is easy to reduce. Therefore, the uniformity and consistency of the structure and performance of the product are better than those produced by conventional forging. , but less than forgings produced by isothermal forging.

During hot die forging, although the billet has a temperature drop, it is still in the forging temperature range, and the deformation resistance does not rise as sharply as in conventional forging. The strain rate used in hot die forging varies within the range of 0.05-0.2s-1. If the strain rate is too low, the blank temperature may decrease.

In hot die forging of titanium alloys, forging heating temperature, strain rate, microstructure of preform and holding time are extremely important factors, which play a decisive role in the dimensional accuracy and microstructure of formed parts. Usually lower strain rates and longer dwell times increase the possibility of precision forming. However, the microstructure of the preform has a direct impact on the flow stress and superplasticity of the material, especially on the microstructure after forging. It cannot be attempted to completely eliminate the defects and uneven grains in the raw material through isothermal forging or hot die forging.

At present, whether titanium alloys and high-temperature alloys use hot die forging technology mainly depends on the total cost of forgings or the need for uniformity and consistency of products. The development trend of this process is to use conventional forging preforms, and finally carry out isothermal or hot die final forging.

Matters needing attention in the cutting process of titanium tube

titanium heat exchanger tube are generally divided into two types, one is an extruded type called seamless titanium tube; the other is welded type called welded titanium tube. The Huayu titanium tube manufacturer summarizes the matters needing attention in the cutting process of titanium tubes.

1. If it is semi-automatic cutting, the guide rail should be placed on the titanium tube plane, and then the cutting machine should be placed on the guide rail, and the order should not be reversed.

2. The cutting parameters should be appropriate, and should be reasonably determined according to the thickness of the titanium tube, so as to obtain a good cutting effect.

3. Check whether the cutting gas is unobstructed. If there is a blockage, it should be unblocked in time.

4. Before cutting, the surface should be cleaned and some space should be left, which can facilitate the blowing out of slag.

5. The distance between the cutting nozzle and the surface of the titanium tube should be appropriate, too close or too far is not good.

6. Preheating should be sufficient so as not to affect the cutting process.

7. If cutting workpieces of different sizes, the small ones should be cut first, and then the large ones.

Performance requirements of titanium containers and titanium alloy tubes for petrochemical industry

Titanium and titanium alloys have very good stability in organic compounds, except for five organic acids (formic acid, acetic acid, oxalic acid, trichloroacetic acid and trifluoroacetic acid) at higher temperatures. Therefore, titanium is an excellent structural material in petroleum refining and petrochemical industry, and can be used to make various reactors, pressure vessels, heat exchangers, separator piping, distillation tower top condenser linings, etc.

In oil and gas drilling and production, the UK used titanium drilling and production equipment in a 600m deep, 262°C containing 5% H2S and 25% NaCl. The former Soviet Union adopted titanium pumps, titanium valves and medical titanium plate flushing brine equipment. In order to solve the corrosion of 600-700atm high-temperature H2S, C02 and water vapor at the wellhead of natural gas in my country, Ti-6Al-4V valve plate, valve seat and valve stem are used, and the long-term use effect is very good.

Offshore oil and gas production must endure seawater corrosion and stress corrosion for a long time. Ti-6Al-4V is widely used abroad as oil platform pillars, rope supports, high-pressure pumps, risers and couplings of seawater circulation pressurization systems. Because Ti-6A1-4V is not only resistant to seawater corrosion, but also has high toughness, high yield strength and high fatigue limit. Recently, titanium prestressed oil production pipe joints are selected abroad. This joint is easy to assemble, light in weight, and maintains elastic sealing. Titanium is the best preferred material. my country's offshore oil industry is entering a stage of large-scale development. Currently, the structural parts, key components and equipment of the platform are all imported from abroad, and domestic materials are rarely used. But it can be expected that titanium will find a broad market here.

Classification of medical titanium alloys

Grade 5 Ti-6Al-4V Titanium Bar can be divided into α-type titanium alloys (such as pure titanium series), α+β-type titanium alloys (such as Ti6Al4V, etc.), β-type titanium alloys (such as Ti12Mo6Zr2Fe, etc.) and TiNi shape memory titanium alloys according to the type of material microstructure. There are four types of alloys. Compared with medical stainless steel and cobalt-based alloys, they have the characteristics of small specific gravity, high specific strength, low elastic modulus, corrosion resistance, easy cutting and good biocompatibility.

According to professional standards for surgical implants and orthopedic devices, titanium alloy materials can be classified as "metal materials" in "materials for surgical implants", while Titanium Threaded Forged Fitting materials are used in non-active surgical implants and active surgical implants. In the three major categories of medical devices, implants and orthopedic devices, they can serve as cardiovascular, bone and joint, bone joint, spine, orthopedic devices, cardiac pacemakers and defibrillators, cochlear implants, neurostimulators and other implants The raw material of the product.

The difference between titanium and titanium alloy

Titanium is a single substance, and titanium alloy is a mixture. Therefore, titanium alloys have more diverse properties and wider uses.

Titanium alloy Concept definition: The alloy composed of titanium as the base and other alloying elements is called titanium alloy. Titanium alloy has the advantages of low density, high specific strength, good corrosion resistance, and good process performance, and is an ideal structural material for aerospace engineering.

Research scope: Titanium alloys can be divided into structural titanium alloys and heat-resistant titanium alloys, or α-type titanium alloys, β-type grade 5 titanium sheet, and α+β-type titanium alloys. The research scope also includes forming technology of titanium alloy, powder metallurgy technology, rapid solidification technology, military and civilian use of titanium alloy, etc.

Titanium alloy is a new type of structural material, which has excellent comprehensive properties, such as low density (~4.5g cm-3), high specific strength and specific fracture toughness, good fatigue strength and crack growth resistance, and good low-temperature toughness. Excellent corrosion resistance, some titanium alloys have a maximum operating temperature of 550ºC and are expected to reach 700ºC. Therefore, it has been widely used in aviation, aerospace, chemical industry, shipbuilding, and other industrial sectors, and has developed rapidly. The relationship between (σ0.2/density) and the temperature of light alloys, steels, etc., the specific strength of ASTM F67 Gr2 Titanium Plate is higher than that of other light metals, Steel, and nickel alloys, and this advantage can be maintained up to about 500ºC, so some titanium alloys are suitable for making gas turbine components. About 80% of titanium production is used in the aviation and aerospace industry. For example, titanium alloy accounts for about 21% of the body structure materials of the US B-1 bomber, which is mainly used to manufacture fuselage, wings, skin, and load-bearing components. The body structural material of the F-15 fighter jet uses 7000kg of titanium alloy, accounting for about 34% of the structural weight. In the structural parts of the Boeing 757 passenger plane, titanium alloy accounts for about 5%, and the amount is up to 3640 kg. In the DC10 aircraft produced by Mc-Donnell-Douglas, the amount of titanium alloy is 5500kg, accounting for more than 10% of the structural weight. Titanium consumption in chemical and general engineering fields: the United States accounts for about 15% of its production, and Europe accounts for about 40%. Due to the excellent corrosion resistance, good mechanical properties, and qualified tissue compatibility of titanium and its alloys, it is used to make biomaterials such as prosthetic devices.

0.01mm - 0.5mm ASTM F67 Gr. 23 Titanium Foil

 

Basic Info

Model NO.

ASTM F67 Gr. 23

Surface Treatment

Polished, Pickled

Packing

Plywood

MOQ

20 Kgs

Delivery Time

5-15 Days

Trademark

Allotech

Transport Package

as Per Customer′s Requirement.

Specification

Customzied

Origin

China

HS Code

8108902000

Product Description

Our commitment to providing grade 1 titanium foil products with the highest quality is the cornerstone of our success. Allotech strives to provide our customers with personalized material solutions designed to suit their needs and manufacturing processes.

Processing	Cold rolling, Annealed
Standard	ASTM B265, ASTM F136, ASTM F67
Thickness	0.01 mm - 0.5 mm
Width	20-600mm
Length	As Your Required
Grade	Gr1, Gr2, Gr3 , Gr23, etc.
Surface	No burr No oil spots
Packaging	Wooden cases

Applications:
Grade 2 Pure Titanium Foil in the coil is mainly applied to electron, chemical industry, horologe, glasses, ornaments, sports good, mechanical equipments, galvanizing apparatus, environmental protection, golf, medical, precision processing industry and so on. 

Features:
Corrosion resistance
Low modulus of elasticity
Good heat-exchanger performance
Non magnetic
Suction performance
Bear high & low temperature, etc
Nonmagnetic and Non-toxic

Detection:
Visual inspection to check surface quality, ensuring without any flaw, black and any other defects.
Chemical Composition Detection, making sure all chemical components can meet your demands.
Mechanical Features testing, making sure all titanium foils have satisfying mechanical features before delivery.

Quality Assurance:
According to globally recognized standards, such as ASTM, AMS, ASME, JIS, MIL.
Chemical composition, Mechanical properties, making sure no defects inside the products.
ISO Quality Management System.

Characteristics and precautions of titanium alloy tube

Generally, the environment for titanium tube manufacturers to repair and weld titanium tubes cannot have flowing air, and other aspects are the same as repair welding in a welding box. But special attention should be paid to:

1. The repair welding area should not be too large, the flow of nitrogen gas should be larger during the repair welding process, and the gas cannot be stopped in the middle;

2. After repair welding, nitrogen protection should be continued until the area cools down;

3. For some special castings, such as complex thin-walled castings, in order to prevent oxidation on the back of the repair welding area, argon can be blown to the back until the casting cools down;

4. It is required that repair welding operators have a high technical level.

In order to obtain titanium tube castings with good repair welding quality, the following points should be paid attention to during the repair welding process:

1. The surface of the repaired castings must be cleaned and dried, and the castings are not allowed to be touched directly with hands before they are put into the welding box.

2. In the process of repairing grade 5 titanium sheet, strictly prevent the short circuit between the tungsten electrode and the repaired part, which will cause the tungsten electrode to break and cause tungsten inclusions in the solder joints.

3. When the area and depth of the repair welding area are relatively large, the remote layer welding should be divided into multiple times, and the next layer of welding can only be performed after the previous layer of welding layer is completely cooled. It is absolutely not allowed to weld in one time. Prevent casting deformation.

4. When the repair welding is about to end, the current should be gradually reduced to reduce the melting zone. Therefore, it is recommended to use pulse current to prevent sudden arc breaking and cracks.

5. After repair welding, the casting should be cooled in the box for a period of time before taking out the casting to prevent cracks or deformation in the welding area of ​​the casting caused by rapid cooling; the cooling time depends on the wall thickness of the casting, usually 15-30mm.

6. After the repair welding of titanium tube castings, it should be annealed or hot isostatic pressed in time, and it should not be left for too long, usually no more than 5 days.

7. The number of welding repairs cannot exceed the provisions of the relevant technical documents.