Bt6 Bt1-0 Bt1-00 PT3B PT7m PT1m Titanium Pipe

Bt6 Bt1-0 Bt1-00 Pt3b PT7m PT1m Titanium Pipe

Titanium ingot	Bt6 Bt1-0 Bt1-00 Pt3b PT7m PT1m (dia 370 - 510 mm)
Titanium slab	Bt6 Bt1-0 Bt1-00 Pt3b PT7m PT1m
Titanium bar
hot rolled bar	dia 10 to 330mm, different grades
cold rolled bar	dia 10 to 330mm, different grades
forged bar	dia 60 to 330mm, different grades
turned bar
titanium 5V forged bar	dia 470 - 510 mm
Titanium sheet	0.5 to 10 mm different alloys
Titanium plate	11 to 80mm VT1-0, VT6,  ОТ4, VТ20, VТ14, PT-3V, SP-3V
Titanium seamless tube	we take orders for production
Titanium welded tube	Bt6 Bt1-0 Bt1-00 Pt3b PT7m PT1m Titanium Pipe
Titanium wire	titanium welding wire 1 to 6 mm in coils
Titanium tank	we take orders for production according to customer's drawings

Under your specific order we will consider manufacture of
titanium hot rolled bar , titanium forged bar, titanium turned bar
titanium sheet 0.5 to 10mm thickness
titanium plate 11 to 100 mm thickness
Titanium seamless tube, titanium welded tube
titanium wire
titanium ingot
titanium slab
titanium equipment - titanium heat exchangers, titanium tanks; titanium details - titanium rings, titanium flanges, titanium disks
titanium billets for casting and stamping
Chemical composition and mechanical properties of titanium seamless tube according to GOST, TU and Titanium tubeASTM B337

Grade	Chemical composition, %											Mechanical properties				Specification or
	N	C	H	Fe	O	Al	V	Zr	Residual, max		Ti	sB,MPa	s0,2MPa		d,%	technical
	max	max	max	max	max				each	total			min	max	min	requirements
Titanium tube      Grade 2	0.03	0.1	0.015	0.3	0.25	-	-	-	0.1	0.4	base	345	275	450	20	ASTM B 337  Titanium tube
Titanium tube      V 1-0	0.04	0.07	0.01	0.25	0.2	0.7max	-	-	-	0.3	base	343-568	-	-	24	GOST 22897-86  Titanium tube
Titanium tube      Grade 9	0.02	0.05	0.013	0.25	0.12	2.5-3.5	2.0-3.0	-	0.1	0.4	base	860A)  620B)	725A)485B)	-	10A)  15B)	ASTM B 337  Titanium tube
Titanium tube      PT 3V	0.04	0.1	0.006	0.25	0.12	3.5-5.0	1.2-2.5	0.3	-	0.3	base	735	617	-	12	TU-3-1280-84  Titanium tube

Chemical composition and mechanical properties of titanium baraccording to GOST 26492-85 and titanium bar ASTM B 348

Grade	Chemical composition, %									Mechanical properties				Alloy composition
	N	C	H	Fe	O	Al	Residual, max		Ti	sB,MPa	s0,2,MPa	d,%	y,%	%
	max	max	max	max	max	max	each	total		min	min	min	min	Al	V
Titanium barGrade 2	0.03	0.1	0.013	0.3	0,25	-	0,1	0,4	base	345	275	20	30	-	-
Titanium barGrade     VT 1-0	0.04	0.07	0.01	0.25	0.2	0.7	-	0.3	base	345	-	15	40	-	-
Titanium barGrade 5	0.05	0.1	0.013	0.4	0.2	-	0.1	0.4	base	895	825	10	25	5.5-6.75	3.5-4.5
Titanium barVT 6	0.05	0.1	0.015	0.6	0.2	-	-	0.3	base	905-1050	-	10	30	5.3-6.8	3.5-5.3
Titanium barVT 6s	0.04	0.1	0.015	0.25	0.15	-	-	0.3	base	835-980	-	10	30	5.3-6.5	3.5-4.5

Chemical composition and mechanical properties of titanium plate according to
GOST 23755-79 and titanium plate ASTM B 265

Grade	Chemical composition, %									Mechanical properties					Alloy composition
	N	C	H	Fe	O	Al	Residual, max		Ti	sB,MPa	s0,2,MPa		d,%	bend test	%
	max	max	max	max	max	max	each	total			min	max	min		Al	V	Sn
Titanium plate        Grade 9	0.02	0.1	0.015	0.25	0.15	-	0.1	0.4	base	620 min	485	-	15	57o	2.5-3.5	2.0-3.0	-
Titanium plate        PT-3V	0.04	0.1	0.006	0.25	0.15	-	-	0.3	base	880 max	-	-	10	120 o	3.5-5.0	1.2-2.5	-
Titanium plate        Grade 6	0.05	0.1	0.015	0.5	0.2	-	0.1	0.4	base	830 man	795	-	10	87 o	4.0-6.0	-	2.0-3.0
VT 5-1	0.05	0.1	0.015	0.3	0.15	-	-	0.3	base	730-930	-	-	6	90 o	4.3-6.0	1	2.0-3.0
Titanium plate        Grade 2	0,03	0,10	0,015	0,30	0,25	-	0,1	0,4	base	345 min	275	450	20	57 o	-	-	-
Titanium plate        VT 1-0	0,04	0,07	0,010	0,25	0,20	0,7	-	0,30	base	370-570	-	-	13	40 o	-	-	-

Main composition Other elements 

Grades	Ti	Al	Mn	Mo	V	Zr	Cr	Tin	Si	Fe	C	Fe	Si	Zr	O	N	H	Res	Grades
Titanim bar VT1-0	base										0,07	0,25	0,1		0,2	0,04	0,01	0,3	Titaniumsheet
																			VT1-0
Titanim bars	base	0.4-1.4	0.5-1.3								0,1	0,3	0,12	0,3	0,15	0,05	0,012	0,3	Titanium sheets
OT4-0																			OT4-0
Titanim tube	base	1.5-2.5	0.7-2.0								0,1	0,3	0,12	0,3	0,15	0,05	0,012	0,3	Titanium plate
OT4-1																			OT4-1
Titanim tubes	base	3.5-5.0	0.8-2.0								0,1	0,3	0,12	0,3	0,15	0,05	0,012	0,3	Titanium plates
OT4																			OT4
Titanim bar VT5-1	base	4.3-6.0						2.0-3.0			0,1	0,3	0,12	0,3	0,15	0,05	0,015	0,3	Titaniumsheet
																			VT5-1
Titanim bars	base	4.3-6.0									0,1	0,3	0,12	0,3	0,2	0,05	0,015	0,3	Titanium sheets
VT5																			VT5
Titanim tube	base	5.3-6.8			3.5-5.3						0,1	0,3	0,1	0,3	0,2	0,05	0,015	0,3	Titanium plate
VT6																			VT6
Titanim tubes	base	5.3-6.5			3.5-4.5						0,1	0,25	0,15	0,5	0,15	0,04	0,015	0,3	Titanium plates
VT6S																			VT6S
Titanim bar VT3-1	base	5.5-7.0		2.0-3.0			0.8-2.0		0.15-0.40	0.2-0.7	0,1			0,5	0,15	0,05	0,015	0,3	Titaniumsheet
																			VT3-1
Titanim bars	base	5.8-7.0		2.8-3.8					0.20-0.40		0,1	0,3		0,5	0,15	0,05	0,015	0,3	Titanium sheets
VT8																			VT8
Titanim tube	base	5.8-7.0		2.8-3.8		1.0-2.0			0.20-0.35		0,1	0,25			0,15	0,05	0,015	0,3	Titanium plate
VT9																			VT9
Titanim tubes	base	3.5-6.3		2.5-3.8	0.9-1.9						0,1	0,25	0,15	0,3	0,15	0,05	0,015	0,3	Titanium plates
VT14																			VT14
Titanim bar VT15	base	2.3-3.6		6.8-8.0			9.5-11.5				0,1	0,3	0,15		0,12	0,05	0,012	0,3	Titaniumsheet
																			VT15
Titanim bars	base	1.8-3.8		4.5-5.5	4.0-5.0						0,1	0,25	0,15	0,3	0,15	0,05	0,015	0,3	Titanium sheets
VT16																			VT16
Titanim tube	base	7.2-8.2		0.2-1.0		10.-12.			0.05-0.18		0,1	0,15			0,14	0,05	0,015	0,3	Titanium plate
VT18																			VT18
Titanim tubes	base	6.2-7.3		0.4-1.0		3.5-4.5		2.0-3.0	0.10-0.25		0,1	0,2			0,14	0,04	0,015	0,3	Titanium plates
VT18u																			VT18u
Titanim bar VT20	base	5.5-7.0		0.5-2.0	0.8-2.5	1.5-2.5					0,1	0,25	0,15		0,15	0,05	0,015	0,3	Titanium
																			sheet
																			VT20
Titanim bars	base	4.4-5.7		4.0-5.5	4.0-5.5		0.5-1.5			0.5-1.5	0,1		0,15	0,3	0,18	0,05	0,015	0,3	Titanium sheets
VT22																			VT22
Titanim tube	base	4.0-6.3		1.5-2.5	4.0-5.0		0.8-1.4			0.4-1.0	0,1		0,15	0,3	0,15	0,05	0,015	0,3	Titanium plate VT23
VT23
Titanim tubes	base	6.2-7.2		1.5-2.5		0.8-2.5			0.10-0.25		0,1	0,25	0,1		0,15	0,04	0,015	0,3	Titanium plates
VT25																			VT25
Titanim bar PT1M	base	0.2-0.7									0,07	0,2	0,1	0,3	0,12	0,04	0,006	0,3	Titanium
																			sheet
																			PT1M
Titanim bars	base	1.5-2.5			1.0-2.0						0,07	0,2	0,1		0,12	0,04	0,003	0,3	Titanium sheets
2V																			2V
Titanim tube	base	3.5-5.0			1.2-2.5						0,1	0,25	0,12	0,3	0,12	0,04	0,006	0,3	Titanium plate PT3V
PT3V
Titanim tubes	base	3.5-5.0									0,1	0,25	0,12	0,3	0,15	0,04	0,006	0,3	Titanium plates
3M																			3M
Titanim bar PT7M	base	1.8-2.5				2.0-3.0					0,1	0,25	0,12		0,15	0,04	0,006	0,3	Titanium
																			sheet
																			PT7M
Titanim bars	base	4.4-6.0		0.7-1.4	1.0-1.9						0.06-0.1	0,25	0,12	0,1	0,13	0,04	0,005	0,3	Titanium sheets
5V																			5V

Established in 1993, Daji Industrial is one of the largest bt6 bt1-0 bt1-00 pt3b pt7m pt1m titanium pipe manufacturers and suppliers in China, offering the price list and excellent services. Should you're interested in it, please be free to buy the cheap and quality products made in China at low price from our factory.

We are the best manufacturer of Titanium and Titanium alloy.It's widely used in the field of aerospace, vessels, weapons, electricity and electronic products, instrument and meters, vehicles, oil exploration and medical equipment.

 

Main characteristics of titanium tube used for seawater desalination:

1, The density is small, specific strength (strength / gravity) high

The density of titanium is 4.51g/cm3, which is lower than that of steel, copper and nickel. However, the specific strength of the metal is located in the first, 3 times of stainless steel, aluminum alloy is 1.3 times;

2, Good corrosion resistance titanium is a very lively metal, its balance potential is very low, in the medium of the great tendency of thermodynamic corrosion. But in fact, titanium is stable in many mediums, such as titanium, which is resistant to oxidation, neutral and weak reduction. This is because titanium and oxygen have a great affinity, in the air or oxygen containing medium, the titanium surface to produce a dense, strong adhesion, inert oxide film to protect the titanium matrix is not corrosion. Even if the mechanical wear will soon self-healing or re regeneration. This indicates that titanium is a metal with strong passivation tendency. The oxidation film of titanium is kept at the temperature of 315 DEG C. 3, the coefficient of thermal conductivity of heat transfer performance of titanium is low carbon steel and copper, but the corrosion resistance of titanium is excellent, so the wall thickness can be greatly thinned, and the surface heat and steam for dropwise condensation, reducing the heat group, too surface can also reduce fouling resistance, so that the heat transfer performance of titanium increased significantly.

4, Good heat resistance of titanium alloy can be used at a temperature of 600 degrees or higher for a long time.

5, The low temperature performance of titanium alloy TA7 (Ti-5Al-2.5Sn), TC4 (Ti-6Al-4V) and Ti-2.5Zr-1.5Mo as the representative of the low temperature titanium alloy, the strength increases with the decrease of temperature, but the plastic change is not big. 6, the tensile strength and its yield strength close to the performance of titanium that its yield strength (tensile strength / yield strength) is high, indicating that the titanium material in forming plastic deformation. Because of the large ratio of yield limit and elastic modulus of titanium, the springback of titanium is large.

The titanium tube is of low quality, high strength and excellent mechanical properties.It is widely used in heat exchange equipment, such as pipe heat exchanger, coil heat exchanger, coil heat exchanger, condenser, evaporator and conveyer pipe.Many nuclear power industries use titanium tubes as their standard tubes

With the rapid development of modern science and technology and the need of national economic construction, the demand for various titanium pipes of various industrial sectors is increasing, and the specifications and technical requirements of titanium tubes are becoming higher and higher.In particular, with the development of market economy, all kinds of industries require more and more titanium tubes.Although titanium pipe USES the somewhat different, but the general requirements of the titanium pipe is consistent, namely, processing conditions and end use requirements of titanium tubes for this purpose the required size, precision and the corresponding performance and the quality indexes such as surface finish.Whether the quality of the titanium tube can meet the various requirements of the user units on the titanium pipe will directly affect the economic benefit of the user or the processing industry and the economic benefits and credibility of the unit.

 

Production practice, however, tells us that in spite of industrial pure titanium pipe market prospects look good, but as a result of industrial pure titanium pipe production has the certain difficulty, especially the pickling, heat treatment and rolling technology is reasonable, will have direct effects on titanium pipe quality and production efficiency, therefore, how to effectively develop all kinds of production process is a concern of this paper.

 

2. Characteristics and application of industrial pure titanium tube

 

Titanium is malleable.The elongation rate of high purity titanium can reach 50 ~ 60 %, and the reduction of area can reach 70 ~ 80 %.

 

Although high purity titanium intensity is low, pure industrial titanium contains a small amount of impurity and addition of alloy elements can significantly strengthen its mechanical properties, so that its strength can be compared with that of high strength.This means that in the industrial pure titanium tube, as long as it contains a small amount of interstitial impurities and other metal impurities, it can be both high strength and suitable plasticity.

 

The ratio strength (strength and weight ratio) of the industrial pure titanium tube is high in the metal structure material, and its strength is similar to that of steel, but its weight is only 57 % of the steel.In addition, the heat resistance of the titanium pipe is very strong, in the 500 ℃ in the atmosphere can still maintain good strength and stability.Titanium pipe also has good low temperature resistance, even in - under the temperature of 250 ℃, it still has the high impact strength, resistant to high voltage shock resistant.

 

Another remarkable characteristic of industrial pure titanium pipe corrosion resistance is strong, this is due to its affinity for oxygen particularly big, can generate a layer of dense on its surface oxidation film, can protect the titanium from corrosion medium.Therefore, titanium has good stability in acidic, alkaline, neutral saline solution and oxidizing medium, which is better than existing stainless steel and other nonferrous metals.

 

Of industrial pure titanium pipe application range is very wide, the current industrial pure titanium tube in the aerospace and aviation industry not only has very important application, and has been in chemical, petroleum, light industry, power generation, etc are widely used in many industrial departments. 

 

Because of industrial pure titanium tube with light weight, strong strength, heat resistance, corrosion resistance and so on many superior characteristics, and is known as "the future of metal", is a very promising a new kind of structural material.

 

Industrial pure titanium tube production process discussion

 

3. 1 product outline

 

Blank specification: phi 76mm x 7mm

 

Product specification: phi 45mm x 1. 25mm 6M scale

 

Size deviation: delta D + 0.3mm / 0.3mm / 0.18mm (protocol requirements)

 

Product standard: GB/t3625-1995

 

3. Formulation of process flow

 

The process flow of pure titanium tube in production is as follows:

 

Surface treatment - blanking - rolling - to - oil - drying - scale shear - annealing straightening - acid - rolling - finished products to the oil - drying - annealing - straightening - finished cutting - acid - inspection - packing

 

(note: the above processes may be added or reduced according to product specifications and performance requirements.)

 

For the titanium tube billet, which is lubricated by copper plating prior to rolling, the process of copper plating will be added together before the surface treatment of the process surface.

 

3. The formulation of pickling process

 

In the process of industrial pure titanium tube production, pickling is a very important process and cannot be ignored.Because the titanium tube is in the process of heat processing or heat treatment, in the absence of the atmosphere of protection, the oxygen and other gases in the furnace can be chemically formed to produce the oxide layer.The oxide layer generated by the titanium tube is very harmful to the process after pickling and the quality of the final product.Such as titanium belt the oxide layer of rolling, will make pipe defects, also because of the existence of oxide layer, into the pipe on the surface, the oxide layer pressure resulting unsatisfactory surface.Directly affect the quality of titanium tube products, material consumption, productivity and economic benefits.

 

It is well known that pickling is the process of removing the surface oxidation layer for metals in acids, bases, salts and their solutions.There are many ways to clear the oxide layer, and the traditional method is to use inorganic strong acids, such as sulfuric acid H2SO4, hydrochloric acid (HCI), nitric acid (HNO3) and hydrofluoric acid (HF).This method is used to remove the oxide layer from the chemical reaction of the oxidation layer and the acid.According to the characteristics of different materials, one of them can be adopted.

 

In the oxide layer of the industrial pure titanium pipe, titanium dioxide (TiO2) is the main layer, and then there are many low-price titanium oxides, such as TiO, Ti2O3 and TiO5.In addition, there are high price oxides of titanium such as TiO3.Research proves that at room temperature, titanium tube in < 5% of the acid in dilute sulfuric acid pickling solution generated on the protective oxide layer in the surface of titanium tube, titanium protection not continue to be dilute sulphuric acid erosion, but in > 5% of sulfuric acid pickling is obvious reaction with titanium.At normal temperature, about 40% of sulfuric acid has the fastest corrosion rate of titanium.Concentration < 5% of hydrochloric acid at room temperature do not react with titanium, when temperature increases, even a dilute hydrochloric acid can be corrosion of titanium, but > 10% hydrochloric acid at 70 ℃ with and 1% hydrochloric acid at 100 ℃ for titanium obvious corrosion.However, when the hydrochloric acid solution has oxidized layer or metal ion (such as copper), it can reduce the corrosion effect of hydrochloric acid on titanium.Hydrofluoric acid (HF) is the strongest solvent for titanium.Even if the concentration is 1 % hydrofluoric acid, it can react with titanium:

 

2Ti + 6HF = 2TiF3 + 3H2

 

When metal ions such as iron and copper are present in hydrofluoric acid solution, the dissolution of titanium can be accelerated.

 

The surface roughness of the titanium tube is the most likely to react with cold and hot dilute nitric acid (HNO3) :

 

3Ti + 4H2O = 3H4TiO4 + 4NO

 

3Ti + 4h2 + H2O = 3H2TiO3 + 4NO

 

In view of the corrosion characteristics of various acids to titanium pipes, in order to effectively remove the oxide layer of the titanium tube surface, the information about the use of nitric acid plus hydrofluoric acid in the acid wash of titanium tube is introduced. The formula and process are as follows:

 

The solution concentration ratio is:

 

(35% ~ 40%) HNO3 + (5% ~ 7%) HF + H2O

 

Solution temperature at 30 ℃ to 50 ℃

 

There exist certain disadvantages to the trials show that the above formula and process: one is titanium tube into the acid reaction too violent, the acid temperature rise quickly, and even to make acid boiling, this situation is easy to cause oxidation burning, titanium tube substrates resulting in titanium matrix loss increase;The second is the acid that is splattered in the process of such intense reaction, which is of considerable harm to the operator.Third, the worker's operating environment is poor, the pollution is too big.In view of the above reasons, the acid and wash formulation and process of titanium tube are adjusted as follows:

 

Main ingredients: nitric acid (HNO3) + hydrofluoric acid (HF)

 

The solution concentration ratio is: (25 % ~ 28 %) HNO3 + (3 % ~ 5 %)

 

Solution temperature is: 30 ℃ or less

 

Pickling time: 10 minutes to 20 minutes

 

It has been proved that the acid washing is better after adjustment, the titanium tube enters acid reaction and the rate of pickling loss can be reduced by 30% ~ 50%.

 

It should be noted that the titanium tube after pickling must be washed and dried.Because of titanium tube after acid pickling in acid solution, although achieved the purpose of removing oxide layer, but the titanium tube surface is eroded by acid or part of the residual acid, more or less the residual acid such as not to get rid of, will be due to the chemistry of the residual acid, make part of the hydrogen diffusion in the titanium tube substrate, lower the titanium tube and plastic.At the same time, the residual acid on the surface of the titanium tube will cause the roller to wear out prematurely and cause the titanium tube to produce waste.Therefore, there is no residual acid in the surface of the titanium tube.

 

The purpose of drying is to drive out the hydrogen atoms in the metal lattice in time, so as to avoid the hydrogen embrittlement of the titanium tube during rolling, and improve the lubrication performance.

 

3. The formulation of rolling process

 

The production practice proves that different kinds of rolling process will be obtained for the same steel tube.Therefore, it is the main condition for ensuring the high yield and high quality of the industrial pure titanium pipe, which is a basic and comprehensive technical subject in the production of pure titanium pipe.

 

In the past, the production of products that have not been produced has been determined by the experience and data access of brother units.The experience gained from the success or failure of production practice is undoubtedly valuable and reliable.However, the scope of its application is local, such as mill equipment, other strength, elastic deformation, wear, plastic deformation, mechanical parameter estimation, etc.To this end, for proposed titanium tube rolling technology, the comprehensive performance of industrial pure titanium tube, characteristics, the condition of tube billet, finished product delivery requirements standard and mill equipment capability, under the production conditions, and so on and so forth.

 

The rolling process of phi 76mm x 7mm industrial pure titanium tube rolled into phi 45mm x 1.2mm is determined as follows:

 

Phi 76 mm x 7 mm - phi 51 mm * 3 mm - 48 mm x 2 mm - phi phi 45 mm x 1. 2 mm

 

To be sure, the rolling phi 51 mm * 3 mm specifications of industrial pure titanium tubes, arakawa tube, the outer wall lubrication MOS2 lubricant coating should be adopted, it is forbidden to use chlorinated paraffin lubricant, in order to prevent the pipe produced in the process of rolling high temperature and the reaction of chlorine ion, causing corrosion pipe matrix.

 

3. 4 formulation of heat treatment process

 

Heat treatment is different from rolling process. It does not change the size and shape of the industrial pure titanium tube, nor does it destroy the titanium tube, but essentially change or improve the performance of titanium tube.It is to use the industrial pure titanium tube to heat, heat and cool in the solid state to change its organization, so as to obtain the required performance of a process operation. 

 

In the process of rolling, the industrial pure titanium tube has the same basic characteristics as other steel pipes, namely that the tube after rolling will produce a change of shape and size that cannot be recovered by itself - plastic deformation.

 

In the process of plastic deformation, the organization and performance of the industrial pure titanium tube also change.Is one of the main work hardening, namely with the increase of deformation degree, deformation resistance increased, higher strength and hardness and plasticity, toughness drops, as to make the titanium tube in cold rolling when the amount of power consumption increases and rolling is restricted. 

 

The purpose of heat treatment is to make the industrial pure titanium tube organization transformation and recrystallization, to restore its plastic before rolling, eliminate in the process of rolling of "work hardening" or because of the hot extrusion process of cooling of heat caused by the uneven residual stress, the existence of the residual stress decreased with the plasticity of titanium tube.Or eliminate the defects caused by the improper heat extrusion process, so that the rolling can be continued.It can be seen that heat treatment is an important process in rolling process.

 

The industrial pure titanium tube annealed in the non-protective atmosphere will produce the oxide layer.Its main component is titanium dioxide (TiO2).

 

Research proves that the titanium oxide in the air is very slow when the reaction is less than 100 ℃, 500 ℃ is surface oxidation.As the temperature increases, the surface began to dissolve in the titanium oxide layer, oxygen to the metal lattice diffusion inside, but there is no large at 700 ℃ of oxygen into the metal internal lattice.When more than 700 ℃, oxygen to metal internal diffusion speed, at the beginning of the high temperature titanium reaction with oxygen in the air.The thickness of the oxide layer is related to the annealing temperature and time, as shown in table 1.

 

Titanium pipe heat treatment usually adopt chamber furnace through argon collar for a horse, but uneven annealing furnace chamber shape furnace temperature, combined with the collar for a horse sealed performance is poor, although the argon gas protection, but titanium tube surface oxidation is often happened.When severe, the surface of the titanium tube is red grey or gray, from table 1, it can be seen as thicker oxide layer.This can lead to some difficulties in pickling, improper operation of the acid wash or acid washing phenomenon, titanium tube base loss is also larger.Moreover, the fuel and argon gas consumption is also large, resulting in high production costs.In order to improve the heat treatment effect of titanium tube and reduce the production cost, the process of replacing the chamber furnace with continuous roller hearth furnace is as follows:

 

Into the furnace temperature is 720 ℃;Speed is voltage: 4.5v, time: 40 minutes;From temperature 250 ℃;Speed: slow, cold. 

 

It is proved that this type of furnace is treated with titanium tube, and its surface color is yellowish, gradually changing color to gold, finally becoming light blue, and the acid washing is easy to clean.