Monday, September 22, 2014

The principle of titanium alloy and its Characteristics and shortcomings

The principle of titanium alloy TitaniumCN 
Titanium alloy is based on titanium to join other alloy elements.Titanium has two homogenous different crystal: under 882 ℃ to close the six-party alpha titanium structure, above 882 ℃ for body centered cubic beta titanium.
Alloying elements according to their influence on phase change temperature can be divided into three categories:
(1) a stable alpha, increase the temperature of the phase transition element for alpha stable elements, such as aluminum, carbon, oxygen and nitrogen.Including aluminum titanium alloy main alloy elements, it is to improve the alloy at room temperature and high temperature strength, reduce weight, increasing the elastic modulus have obvious effect.
(2) stable beta phase, to reduce the phase transition temperature elements for beta stable elements, and can be divided into two isomorphous and eutectoid type.
The application of titanium alloy products
The former are molybdenum, niobium, vanadium, etc.;The latter has a chromium, manganese, copper, iron, silicon, etc.
(3) the phase transition temperature impact elements to neutral elements, such as zirconium, tin.
Oxygen, nitrogen, carbon and hydrogen is the main impurity of titanium alloy.Oxygen and nitrogen in the alpha phase has larger solubility, to strengthen titanium alloy has a significant effect, but it is plastic.Usually prescribed titanium content of oxygen and nitrogen in under 0.15 ~ 0.2% and 0.04 ~ 0.05% respectively.Hydrogen in the alpha phase solubility is small, dissolve excess hydrogen yield in titanium alloy hydride, alloy become fragile.Usually controlled under 0.015% hydrogen content in titanium alloys.The dissolution of hydrogen in titanium is reversible and can be removed using a vacuum annealing.
disadvantages.
Titanium and titanium alloy limitation is mainly in high temperature and chemical reactivity with other materials.The nature of the force of titanium alloy and conventional refining, melting and casting technology is different, and often causes the damage of mold;As a result, make the price of titanium alloy is very expensive.So they began to use mostly in aircraft construction, aircraft, and used in the oil and chemical industry and other high-tech industries.But because of the space science and technology developed, people's quality of life has increased, so the titanium alloy also gradually used to make consumer goods, for the benefit of life of life, only these prices are still on the high side, belongs to the high price of the product, it is unable to carry forward the Achilles' heel of the biggest titanium alloy.
The main characteristics
Titanium alloy main features;Industrial pure titanium: pure titanium more than chemical pure titanium content of impurities, so its strength and hardness is high, its mechanical properties and chemical properties similar to stainless steel, compared with the strength of pure titanium, titanium alloy is better than that of austenitic stainless steel in terms of oxidation resistance, but poor heat resistance, TA1, TA2 and TA3 higher content of impurities, mechanical strength, hardness, in turn, enhanced, but the plastic toughness decline in turn.

Titanium alloy and Its development course

Titanium is developed in the 1950 s a kind of important structure of the metal, titanium alloy has high strength, good corrosion resistance and high heat resistance and is widely used in various fields.Many countries in the world is to know the importance of the titanium alloy material, carries on the research and development, and the practical application.50 ~ 60 s of the 20th century, mainly is the development of aviation engine with high temperature and the body with the structure of the titanium alloy, titanium alloy developed a batch of corrosion resistant titanium alloy in the 70 s, 80 s, to further corrosion resistant titanium alloy and high strength titanium alloy.Titanium alloy is mainly used to produce aircraft engine compressor components, followed by the rockets and missiles and high-speed plane structure.TitaniumCN

Titanium is developed in the 1950 s a kind of important structure of the metal, titanium alloy has high strength, good corrosion resistance and high heat resistance and is widely used in various fields.Many countries in the world is to know the importance of the titanium alloy material, carries on the research and development, and the practical application.
First practical titanium alloy is in 1954 the successful development of Ti 6 al 4 v alloy, because of its heat resistance, strength, plasticity, ductility, formability, weldability and corrosion resistance and biocompatibility are better, and become the industry in ace alloy, titanium alloy, the alloy usage has 75% ~ 85% of all titanium alloys.Many other titanium alloy can be regarded as Ti 6 al 4 v alloy modification.
50 ~ 60 s of the 20th century, mainly is the development of aviation engine with high temperature and the body with the structure of the titanium alloy, titanium alloy developed a batch of corrosion resistant titanium alloy in the 70 s, 80 s, to further corrosion resistant titanium alloy and high strength titanium alloy.Using the temperature of the heat resistance of titanium alloy has been in the 50 s to 400 ℃ up to 600 ~ 650 ℃ in the 90 s.A2 (Ti3Al) and r (TiAl alloy, the titanium in the use of the engine parts by the engine is cold end (fan and the compressor) to the hot end of engine (turbine) direction.Titanium alloy for high strength, high plastic structure, with high strength and high tenacity, high modulus and high damage tolerance direction.
In addition, since the 1970 s, the Ti, Ni, Ti - Ni - Fe - Ni - Nb, Ti shape memory alloy, and increasingly wide application in engineering.Has developed hundreds of titanium alloy in the world, the most famous of the alloy has 20 ~ 30 kinds, such as Ti 6 al 4 v, Ti - 5-2.5 Sn, Ti - 2 al - 2.5 - Zr, Ti - 32 Mo, Ti, Mo, Ni, Ti - Pd, SP - 700, Ti, Ti - 6242-10-5-3, Ti - 1023, BT9, BT20, IMI829, IMI834
According to relevant statistics, in 2012 China's chemical industry with titanium volume of 25000 tons, less than in 2011.This is since 2009, our country chemical industry with titanium market negative growth for the first time.In recent years, the chemical industry has always been the largest use of titanium processing material, its dosage in titanium has remained at more than 50% of the total amount accounted, the proportion is as high as 55% in 2011.But as the economic downturn, the chemical industry not only decreased significantly in new projects, at the same time will also face adjustment of industrial structure, the partial products new capacity controlled, backward production capacity will be phased out.Affected, its shrinking of titanium processing material consumption has become a natural.Before this, there is industry insiders predict chemical industry with titanium content peaked in 2013 ~ 2015 years.At the current market point of view, the weakness in the overall economy in 2012 is likely to make chemical recession ahead of titanium.

Friday, September 19, 2014

The blanking technology of the titanium alloy forging

                         Forging of titanium alloy forging (rolling) rods Titaniumcn, the alpha layer of the surface with a layer of hard brittle, die forging, need to get rid of this layer, so as to avoid forging billet caused by surface cracking.For less than 50 mm diameter rod, need to remove the surface layer of 3 mm thick, diameter greater than 50 mm, need to get rid of 5 mm.For extrusion bar, less than 50 mm diameter, can be car to 2 mm, greater than 50 mm in diameter, generally to 3 mm.After cutting, there are still defects, such as individual site, partial grinding can be eliminated, the grinding depth should not be greater than 0.5 mm.
Definite size titanium alloy forging blank available anode cutting machine, sawing machine, lathe, punching and shearing machine, grinding wheel cutting machine or cutting on the forging hammer or hydraulic press.The highest efficiency in the punching and shearing machine.
(1) the thickness of the disk saw cutting disc saw blade between 2 ~ 8 mm, suitable for cutting bar diameter is larger.Disk saw the linear velocity of about 30000 ~ 35000 mm/min, the feed amount of hours to get a clean face.To prevent metal bond tools, metal burns, can use suspension to reduce friction, cooling cutting tools.
(2) the cutting of titanium alloy anode, mechanical cutting, incision width of no more than 3 mm, with a concentration of 1.28 ~ 1.32 g/cm3 water as working fluid.Although anodic cutting cut cost less, but less rate is low.
(3) before the hammer or hydraulic press for cutting cutting, bar should be preheated to deformation began cutting temperature (or chop).Pure titanium in punching and shearing machine cold shearing.
(4) lathes cutting of titanium alloy car cutting, cutting speed should be within 25000 ~ 30000 mm/min, feed quantity is 0.2 ~ 0.3 mm/week.
Scalping remove the alpha layer, car to specification: the cutting rate of 15000 ~ 20000 mm/min.No alpha layer when turning the standard related to surface roughness: when the roughness Ra = 0.63 ~ 2.5, feed quantity is 0.08 ~ 0.1 mm/week;Ra = 1.25 ~ 5, the feed quantity is 0.1 ~ 0.2 mm/week;When Ra = 2.5 ~ 10, feed quantity is 0.3 ~ 0.4 mm/week., turning processing must be used when the lubricating coolant supply 1 ~ 1.5 MPa pressure.
(5) grinding wheel cutting of titanium alloy rod diameter less than 60 mm, appropriate is used grinding wheel cutting.When the diameter of the grinding wheel cutting more than 20 mm, should use the cooling fluid.Grinding wheel cutting efficiency is higher, but the life of the grinding wheel piece is shorter.
Blank after cutting, end of the acute Angle should be round.Otherwise end forging or heading on horizontal forging machine, may cause folding.The blank diameter of less than 50 mm, acute Angle round radius R is 1.5 ~ 2.0 mm;The blank diameter of more than 50 mm, acute Angle round radius R is 3 ~ 4 mm.

Forging of titanium

Titanium forging is on titanium TitaniumCN blank sheet (not including) the external force, make its produce plastic deformation, change the size, shape and improve performance, to manufacturing machinery parts, artifacts, tools or blank forming method.
According to the different forging temperature area, in view of the different quality of forgings and forging process requirements, can be divided into three cold forging, warm forging, hot forging forming temperature area.Originally this temperature region division, there is no strict boundaries, generally speaking, the recrystallization temperature region of the forging, called hot forging, no heating forging is called cold forging at room temperature.
When the cold forging, forging the size of the change is very small.Forging under 700 ℃, and less scale formation, and surface decarburization phenomenon.Therefore, as long as the deformation energy within the scope of the forming, cold forging is easy to get good dimensional accuracy and surface finish.As long as the good control of temperature and lubrication cooling, the temperature under 700 ℃ forging can also achieve good accuracy.Hot forging, due to the small deformation and deformation resistance, can be forged shape complicated large forgings.In order to get high dimensional precision forging, can be in 900-1000 ℃ temperature field using hot forging processing.Also, pay attention to improve working conditions for hot forging, die (2-5000 hot forging, warm forging 1-20000, cold forging 2-50000) compared with other temperature field of forging is shorter, but its degree of freedom is big, the cost is low.

To produce when in cold forging deformation and strain hardening, the forging die under high load, therefore, need to use the high strength of the forging die and using hard of lubricant to prevent wear and adhesive processing method.In addition, to prevent crack in billet, intermediate annealing when necessary to ensure deformation ability.To keep good lubrication condition, phosphating of billet.In a continuous process with bar and wire rod, and the current of cross section is not lubrication processing, are studying the possibility of phosphating lubrication method is used.

According to the movement of blank, forging can be divided into free forging, upsetting and extrusion, die forging, closed die forging, closed upset.Closed die forging and closed upset because there is no flash, material utilization ratio is high.With a process or a few process can complete complex forging finishing.Since there is no flash, forging stress area is reduced, the required load is also reduced.However, we should pay attention to not make blank completely is restricted, so we will strictly control the volume, control the relative position of forging die and measure of forgings, effort to reduce the wear and tear of forging.

Monday, September 15, 2014

The reason of chemical equipment from corrosion

With the development of economy, the increasing demand of chemical equipment, more and more the operation of the production equipment is beyond design ability, thus for global chemical enterprise at present, to prevent the corrosion of process equipment for the loss by the failure has become an urgent problem.Many experts agree that material protection and corrosion protection measures is to reduce maintenance costs and make the important guarantee of the safe and stable operation of the factory.In recent years, the chemical engineering construction in the field of competition, in order to reduce the bid price, the bid for the anti-corrosion measures, the use of high quality alloy, surface treatment technology, such as antiseptic coating (including)Titaniumcn
, cathodic protection and on-line corrosion monitoring system such as the importance of clear enough, this behaves particularly outstandingly in the developing world.The chemical industry for new and existing industrial artifacts protection and protection of the demand is higher and higher, people demand for coating and anticorrosion technology is growing rapidly.Corrosion damage everywhere, corrosion accidents occurred frequently, which in addition to corrosion itself has a spontaneous nature, largely because of corrosion harm to estimate shortage, not deep understanding of the importance of corrosion protection, the corrosion and protection they have no knowledge of science, no corrosion protection measures are taken, or improper anti-corrosion measures.The cause of the corrosion damage
(1) there are many in the chemical production has a certain corrosive medium, such as acid, alkali, salt, water, oxygen, and so on, this is one of the principal causes of corrosion.
(2) the operation of overtemperature and overpressure, chemical equipment management is not perfect, thought not value, and the corrosion is the main production
One of the reasons.
(3) chemical equipment equipment structure design is unreasonable, improper material selection, manufacturing process quality, welding residual, lack of anti-corrosion measures or inferior construction quality etc, provides the corrosive environment.The intrinsic factors of corrosion damage
(1) different metal for different media have different ability to resist corrosion.
(2) the metal of the coarse grains, the faster the corrosion.On the other hand, is slower, such as stainless steel is higher than the corrosion resistance of cast iron.
(3) the surface of the parts more rough, more prone to corrosion.The surface of oxide film is corrosion resistant.
(4) the shape of the equipment structure mutation place, such as openings, gaps, or corner position, rapid metal corrosion.
Corrosion damage caused by external factors
(1) the types of media,
Chemical composition, concentration, pH value, impurities, moisture and oxygen scene is the external cause of corrosion.
(2) the higher the temperature of the medium, the higher the pressure, the faster the corrosion, because corrosion is a kind of chemical reaction, every rise 10%, the corrosion speed increase
1 ~ 3 times _l J.Diffusion velocity increases as the temperature increases, and electrolyte resistance of corrosion, so quicken the reaction of corrosion cell.
(3) medium flow, the faster the more easy to corrosion, it will scour protection film, produced vortex, turbulence, cavitation and cause severe
The impact of the heavy wear and cavitation corrosion.
(4) components by external force or the greater the residual stress, the faster the corrosion.
(5) the influence of the stress and fatigue.Equipment stress produces on the one hand, is formed in the process of machining, such as cold working
Stress and organization stress of hot working;On the other hand in the work can also be under pressure or rotating parts of produce should be
Force.The results of the stress the role of causing distortion of the inner metal, reducing the area of the electrode potential, increase micro batteries
Corrosion.Anticorrosive technology of dalian petrochemical company since 1958 since the earliest using modified phenolic epoxy coating anticorrosive, anti-corrosion technology in me
The chemical industry has gained rapid development.The present anti-corrosion technology mainly include: development of corrosion resistant material, the surface corrosion protection technology, corrosion technology, electrochemical protection and so on.

Wednesday, September 10, 2014

The classification of the electrolytic bath

Aqueous electrolytic cell
The form of aqueous electrolytic cell, can be divided into two categories, diaphragm electrolyzer and diaphragm electrolyzer.Diaphragm cell and can be divided into both to membrane (asbestos wool), ionic membrane and solid electrolyte membrane (such as beta Al2O3) form;No diaphragm cell is divided into mercury cell and oxide electrolyzer, etc. titaniumcn
Using different electrolyte, the structure of the electrolytic cell is also different.
Aqueous solution with diaphragm and diaphragm electrolyzer points two kinds.General multi-purpose diaphragm electrolyzer.In chlorate production of chlorine and caustic soda production and mercury method, adopting the diaphragm electrolyzer.As far as possible increase of electrode surface area per unit volume, can improve the production of electrolytic tank strength.Therefore, in modern diaphragm cell electrodes are upright.Electrolytic cell because of different internal components, structure, installation and other materials show different performance and features.
Molten salt electrolytic cell
Much used for preparing low melting point metal, its characteristic is running at high temperatures, and should try to prevent moisture to enter, avoid hydrogen ions on the cathode reduction.When preparing sodium metal, for example, due to sodium ions in the cathode reduction potential is very negative, reduction is difficult, must use do not contain anhydrous hydrogen ions in molten salt or molten hydroxide, lest cathode hydrogen.For electrolytic process should be carried out at high temperatures, such as electrolysis of molten sodium hydroxide at 310 ℃, such as mixed electrolytes containing sodium chloride, the electrolytic temperature about 650 ℃.
The high temperature of electrolyzer can by changing the electrode spacing, the ohmic voltage drop of electric energy into heat energy to achieve.Electrolysis of molten sodium hydroxide, tub available iron or nickel, often due to raw material in electrolysis of molten electrolyte containing chloride inevitably into a small amount of water, can make the anode generated, wet chlorine gas corrosion effect of electrolytic cell is very strong, so the electrolysis of molten chlorides, general use or phosphate ceramic materials, and the part of the role is not affected by chlorine gas available iron.Yin, anode products of molten salt electrolytic cell, also requires properly separated, and should be generalized by the slot as soon as possible, so as to avoid product sodium metal cathode long floating on the surface of the electrolyte, further with the anode product or oxygen in the air.
Nonaqueous electrolytic cell
As a result of nonaqueous solution electrolysis cell in preparing organic products or electrolytic organic matter, often accompanied by a variety of complex chemical reaction, make its application is restricted, industrialization.Commonly used organic electrolyte, low conductivity, response speed and small.Therefore, must use low current density, pole spacing to narrow as far as possible.Using fixed bed or fluidized bed electrode structure has a larger surface area, can improve the cell production capacity.
Classified by the electrode connections
The electrolytic cell according to the electrode connections, can be divided into two categories, unipolar and bipolar electrolyzer.Monopolar type electrolytic cell with the polarity of electrodes and the dc power supply in parallel connection, both sides of the same polarity, electrode at the same time as the anode or at the same time as the cathode.Double pole at the ends of the cell electrodes respectively with that of the dc power supply is connected to the cathode, become the anode or cathode.Current flow through a series of electrodes electrolytic cell, the middle side of each electrode as anode, the other side as the cathode, thus has the dual polarity.When the total area of the electrode at the same time, the complex pole electrolytic cell current is small, high voltage, dc power supply for investment than the single pole type province.Double pole type generally adopt pressure filter structure form, more compact.But easy to leakage and short circuit, groove structure more complicated than the single pole type and operation management.Monopolar type cell cross section is rectangular or square, commonly cylindrical covers an area of big, the space utilization rate is low, use less.

The main structure of electrolytic bath

electrode
The anode
The effect of anode and cathode, on the material requirements also vary.
Points two categories, soluble and insoluble.In the refined copper electrolytic cell, for soluble anode materials for refining crude copper.It into in the process of electrolytic solution, to replenish from the precipitate in the solution on cathode copper.In electrolytic solution (such as salt aqueous solution) using electrolytic cell, for insoluble anode, basic don't change them in the electrolytic process, but for the electrode on the surface of the anode reaction often has a catalytic role.In the chemical industry, USES mostly insoluble anode.titaniumCN
Anode material should meet the basic requirements of general electrode materials (such as electrical conductivity, catalytic activity intensity, processing, source and price), still need strong in anodic polarization and high temperature of the fluid of the anodic dissolution and passivation, has the very high stability.For a long time, graphite anode materials is the most widely used.But porous graphite, mechanical strength is poor, and easily oxidized to carbon dioxide, are constantly in the process of electrolytic corrosion spalling, electrode spacing increases gradually, slot voltage rise.Used in electrolytic salt aqueous solution, the analysis on the graphite electrode overpotential is higher also.
The cathode
With metal or alloy as the cathode, due to the work under more negative potential, often can play a role of cathodic protection, corrosion resistance is small, so easy to choose cathode materials.In aqueous solution in the electrolytic cell, cathode generally produce hydrogen evolution reaction, higher overpotential.So the cathode material of the main improving direction is to reduce hydrogen evolution overpotential.In addition to lead must be used when using sulfuric acid as electrolyte and graphite as cathode, low carbon steel is a common cathode materials.Methods used to reduce power consumption, the current preparation of high specific surface area, and has the catalytic activity of the cathode, such as porous nickel plating cathode.
The diaphragm
In order to prevent the product mix, Yin and Yang poles to avoid the possibility of harmful reaction, in the electrolytic cell, basically use the diaphragm to Yin and anode chamber is separated.Diaphragm needs to have certain porosity, can make the ions, and not make the molecules or bubbles through, when have a current flows through the diaphragm of the ohmic voltage drop.These performance requirements in use process, and requirements in the Yin, the anode chamber under the action of the electrolyte, good chemical stability and mechanical strength.Electrolysis of water, the Yin and the anode chamber with liquid electrolyte, electrolytic cell membrane to separate Yin and anode chamber, in order to ensure the purity of hydrogen, oxygen, and to prevent hydrogen and oxygen mixture explosion.More complex situation is Yin in electrolytic cell anode chamber, different composition of the electrolyte.At this time also need to prevent Yin, anode diaphragm chamber and electrolyte in electrolytic product diffusion effect, such as chlor-alkali production in the diaphragm electrolyzer diaphragm method, can increase the cathode chamber hydroxyl ion diffusion into the anode chamber and migration resistance.

The classification of the titanium anode

Soluble and insoluble anode TitaniumCN
The soluble anode in the electrolysis process of added metal ions and the conductive role, insoluble anode conductive role only.Is the earliest insoluble anode graphite and lead anode of titanium anode in the 1970 s as a new technology used in electrolysis and electroplating industry.The insoluble anode can be divided into two broad categories: chlorine evolution anodes and oxygen evolution anode.Chlorine evolution anodes is mainly used for chloride electrolysis system, in the process of electroplating anode with free chlorine, so called chlorine evolution anodes;Oxygen evolution anode is mainly used for sulfate, nitrate, hydrocyanic acid salt electrolytic fluid system, such as electroplating anode in the process of oxygen is released, so called the oxygen evolution anode.Lead alloy anode oxygen evolution anode, titanium anode respectively according to their different surface catalytic coating effect with functions of oxygen, chlorine, or both.
Chlor-alkali industrial titanium anode
Compared with graphite electrode, the method of diaphragm caustic soda production, the working voltage of graphite anode for 8 a/DM2 coating anode can be multiplied, up to 17 a/DM2.This product can be doubled in the same electrolysis environment, and the raw products of high quality, high purity chlorine.
Plating titanium anode
Plating on titanium substrate with insoluble anode is (mesh, plate, strip, tube, etc.) on the coating with high electrochemical catalytic properties of noble metal oxide coating, coating of valve metal oxide containing high stability.New insoluble titanium anode with high electrochemical catalytic ability, oxygen evolution overpotential is lower than insoluble lead alloy anode is about 0.5 V, significant energy saving, high stability, polluting the plating solution, light weight, easy to replace.New type of titanium insoluble anode of the oxygen evolution potential and less than platinum plating insoluble anode, but life is more than double.Is widely used in various kinds of plating used as anode or auxiliary anode, can replace conventional lead alloy anode, in the same conditions, can lower the cell voltage, save power consumption;Insoluble titanium anode in the electroplating process has a good stability (chemical, electrochemical), long service life.This gold-plated anode is widely used in nickel plating, chrome plating, galvanized, electroplating non-ferrous metals such as copper plating industry.
Lead and lead alloy anode
Belongs to the oxygen evolution anode lead alloy anode, oxygen evolution reaction of the electrolyte for sulfuric acid and sulfate, is mainly used for metallurgical electrolysis.Such anode electrolysis in the process of the defects of geometry size will change.First of all, in the process of electrolysis, lead anode matrix into lead sulfate, and then into the lead.Lead sulfate is a middle tier, it is an insulator, to play the role of a chemical barrier layer, can protect the inner lead substrate in sulfate environment.Lead oxide in the outer layer is the practical significance of electrode, the oxygen evolution reaction, oxygen evolution potential of lead oxide is very high, and with the increase of current density increases rapidly, the feature of lead alloy anode is lead oxide by its outer layers of the inherent characteristics of lead oxide - is a poor conductor of electricity.In addition, in the process of electrolysis, electrochemical properties of lead oxide anode structure constantly attenuation, falls off to produce oxide layers of its internal stress, in addition, the formation of lead oxide and lead to oxide dissolution, as an intermediary lead sulfate is converted to once again lead oxide, become the new outer oxide electric catalytic active substance, the inner layer of lead substrate by oxidation, form a new lead sulfate layer in the middle.As a result, in the process of electrolysis, lead and its alloys are dissolved into electrolyte and precipitation in the solution pollution (chemical precipitation in the solution) and cathode product contamination (contaminants on the surface of the cathode electrodeposition, electrolysis to the purity of copper not good guaranteed).
Coating titanium anode
Coating titanium Anode, called DSA (Dimensionally Stable Anode dimension Stable Anode), also called DSE arithmetic (Dimensionally Stable Electrode), is developed in the late 1960 s, a new type of insoluble Anode material.DSA coating titanium anode is mainly used in the electrochemical and power metallurgy sector.
DSA coating titanium anode application areas are: chlor-alkali industry, chlorate production, production of hypochlorite, perchlorate, persulfate electrolysis, electrochemical organic synthesis, production of electrolytic extraction of non-ferrous metal, electrolytic silver catalyst, manufacturing electrolysis copper foil, electrolytic oxidation recycling mercury, electrolysis, chlorine dioxide production, hospital wastewater treatment, electroplating factory cyanide wastewater treatment, water and food utensils disinfection, power plant cooling circulating water treatment, woolen mill dyeing wastewater treatment, industrial water treatment, electrolysis legal system in acid and alkaline ionized water, copper zinc plated, rhodium, palladium plating, plating, plating lead, electrodialysis desalination, electrodialysis method take tetramethyl ammonium hydroxide, molten salt electrolysis, battery production, cathodic protection, in the production of the cathode foil, aluminum foil anodic oxidation, etc.Applications involving chemical, metallurgical, water treatment, environmental protection, electroplating, electrolysis and other fields in organic synthesis.

The advantages of titanium anode

1, titanium anode TitaniumCN working life is long, the diaphragm method in the production of chlor-alkali industry, metal anode resistance to chlorine and alkali corrosion, anode has six years of life, and the graphite anode is only 8 months.
2, can overcome the graphite anode and lead anodic dissolution, avoid the pollution to the electrolyte and cathode, and thus can improve the purity of metal products.
3, can improve the current density.Diaphragm method in chlor-alkali production, work of graphite anode current density is 8 a/dm2, titanium anode can multiply, up to 17 a/dm2, so in the electrolysis workshop, under the same conditions, yield can increase 1 times, improve the ability of single tank production, effectively improve the labor productivity.In electrolysis under high working current density, the use of titanium anode is good.
4, with metal anode, chlorate cell operation of high temperature, high current density is possible.Metal anode used to improve cell structure, reduces the power consumption, accelerate the hypochlorite angry chlorate in the chemical reaction, so as to improve the production performance.
5, adopt DSA, mercury method and membrane method the design concept of salt electrolytic cell and operating conditions to improve, to reduce energy consumption.DSA low overpotential properties, electrode and electrode surface bubbles easily between, is the important reason for the metal anode electrolyzer cell voltage is lower.
Because the titanium anode has many advantages, it development of chlor-alkali industry made great economic benefits, so soon used widely all over the world.Chlor-alkali production capacity, the world is about 41 million tons/year, adopts the titanium anode is not less than 70%, titanium anode was regarded as a major technological revolution in the chlor-alkali industry.After that, the titanium anode in a lot of electrolytic industry also has been widely applied.
6, anode size stability, CLP interelectrode distance does not change, electrolytic process ensures electrolytic operating under the condition of cell voltage stability.
7, can avoid lead anode after deformation problem of short circuit and current efficiency can be improved.
8, titanium anode light weight, can reduce labor intensity.
9, switch to make easy, but high precision.
10, low work voltage, so the power consumption is small, can save power consumption, dc power consumption can be reduced by 10% ~ 20%.The main reason for the low titanium anode working voltage: 1) active coating titanium anode overpotential of chlorine and oxygen are relatively low.Electrolytic brine in chlor-alkali production, titanium anode for low chlorine overpotential, in 1 a/cm2 is lower than graphite anode 140 mv;2) can decrease the shielding effect "bubbles", metal anode surface generated by the bubble is small, and out quickly, so greatly reduced degree of aeration between electrodes, ohmic drop between the poles of about 700 mv, air bubble diameter is about 3 mm;3) to reduce the resistance of the anode structure;4) shortens the interelectrode distance.[1]
In the 1960 s, the world salt electrolysis industry consume about 150 billion degrees, use metal anode, each year about 300 million degrees can save electric energy.
After 11, in chlor-alkali production, the use of titanium anode, products with high quality and high purity chlorine, including CO2, alkali concentration is high, can save heating steam, saves the energy.
12, corrosion resistance is strong, can be in many highly corrosive, electrolytic medium with special requirement.
13, titanium substrate metal can be used repeatedly.
14, the presence of the metal anode, the use of chlor-alkali industry in the recent emergence of ionic membrane electrolysis with the latest technology to design and realize industrialization.

Friday, September 5, 2014

The advantage of copper nickel alloy condenser pipe used in ship industry

Heat exchanger and condenser in power plants, chemical plants, petrochemical equipment, and plays a significant role in many fields such as pharmaceutical, food machinery, one of the important equipment which is the important component of heat exchange tube and condensation tube, it directly affects the service life of the unit, Ann, efficiency, heat exchanger and the number of condenser tube is very much, the cost of heat exchanger and the condenser of the cost of 60% 80%, therefore, selects the high ratio of performance and condensation tube heat exchange tube of metal materials, is the crucial one annulus.TitaniumCn
The material, and heat exchange tube condenser pipe shall have excellent heat transfer performance, more want to have good resistance to corrosion, erosion and abrasion resistance, also should have good strength and rigidity and good plasticity, easy processing and manufacturing.
Nickel copper alloy condenser pipe, it is a kind of tubing used in cooling equipment, water cooling system is mainly used in ships.First is to use tin brass, then add the arsenic, so as to improve the quality of the condenser pipe and life.If add Mn, Ni, and trace rare earth elements, can further improve on the strength and corrosion resistance.At present, the main is to use and BF10 BFe30-1-1-1-1.
That compared with titanium, stainless steel material, what is the difference between the three?
(1) titanium
In the future, may use titanium instead of copper and nickel alloys, as the material of ships to the condenser.Because big place in sea water flow, if you use the monel alloy, because its price is too high, so the use value is not high.The use of copper and nickel alloy material, although it is commonly used materials, but cannot be used for a long time, life is limited, so need to be replaced on a regular basis.And titanium, it will not be in all concentrations of sulfide corrosion, so the seawater containing sulfide has good corrosion resistance, service life is longer.
In addition, the heat conduction performance of the titanium is poorer, but by the method of using thin-wall titanium tube can be improved.But overall, titanium condenser pipe compared with nickel copper alloy condenser pipe, there are still some problems.The production and processing of titanium is difficult, production is not high also, and expensive, so the price is not dominant.
(2) stainless steel
It is hard to become the condenser pipe material, because its thermal conductivity for only 38% of copper and nickel alloy, while the corrosion rate and corrosion rate is better than that of copper and nickel alloy, but to solve a problem, that is the problem of biofouling prevention, if you can't solve this problem well, so will affect the use effect.

Titanium mesh can be applied to high temperature resistant filter, shipbuilding, war industry manufacturing, etc.

Titanium mesh is mainly used in acid, alkali environment conditions screening and filter or separation of gas and liquid filtration, and other medium.Plain weave, twilled weave, dense weave the three methods.As a result of the titanium wire drawing is difficult, the current domestic drawing comparison is incredible titanium wire of the finest can do 0.1 mm, titanium wire of low elongation, strength, elasticity, flexibility, low.Great limits the high orders, the production of titanium mesh.The specifications of the titanium mesh 1-100 mesh.Anpingxian have years of experience in screen production, the production of titanium net has the characteristics of filtering performance is stable, fine.
Is the most common method of weaving, the main characteristic is the density of warp and weft wire diameter is the same. TitaniumCN
Twill titanium mesh is suitable for the petroleum, chemical, chemical fiber, aerospace and other industries, has a good acid and alkali resistance, resistance to high temperature, strong tensile resistance and wear resistance properties.
Pure titanium dense mesh plain weave, twill weave a pure titanium lp network performance: has the characteristics of filtering performance is stable, fine.Usage: used for aerospace, petroleum, chemical industry, etc.
Material: GR1, GR2, GR3, R50250, titanium alloy, etc
Material surface: 1. The black surface (containing graphite coating) 2. The light (no graphite coating)
The corrosive resistance characteristics of titanium mesh
High purity titanium mesh in corrosion medium environment, generated on the surface of a dense layer of oxide film, strong adhesion, large inertia, the passivation phenomena, protect the titanium mesh substrate from corrosion, so as to achieve strong corrosion resistance;Especially in the use of the following environment more excellent corrosion resistance, such as: water, wet chlorine, chlorite and hypochlorite solution, nitric acid, chromium acid metal chloride and organic salt (such as nitric acid of 60%, pure titanium mesh in nitric acid solution in the corrosion speed of only 0.001 mm. A - 1);The "twelfth five-year" plan for energy conservation and emissions reduction requirements of the state council, promote the traditional industry upgrade, speed up the use of high technology and advanced applicable technology to upgrade traditional industries.Titanium mesh with excellent corrosion resistant performance to replace traditional material, such as no nickel metal material such as stainless steel net, aluminum net, pure titanium mesh long service life, safe and reliable operation.
Titanium mesh can be applied to high temperature resistant filter, shipbuilding, war industry manufacturing, chemical filter, mechanical filter, electromagnetic shielding wire mesh, mesh, high temperature furnace heat treatment desalination network, oil filter, food processing, medicine, filtering, etc.

The special properties of nickel and titanium alloy

1, the characteristics of shape memory (shape memory) shape memory is when the mother of a certain shape by Af temperature cooled to Mf temperature above the following after the formation of martensite, the martensite temperature deformation under Mf, and through heat below Af temperature, along with the inverse transformation, material will automatically restore its shape in the parent phase.Actually shape memory effect is one of the nickel titanium alloy by thermal induced phase transformation process. titaniumcn
2, super elasticity (superelastic) of hyperelastic refers to the sample production under external force is greater than the elastic limit stress strain variable, the phenomena of strain can be automatically restored when unload.Namely in the parent phase state, as a result of the action of applied stress, cause stress induced martensite phase transformation, thus alloy showed different from ordinary material mechanics behavior, its elastic limit is far greater than ordinary materials, and no longer comply with hooke's law.Compared with shape memory properties, hyperelastic without heat.To sum up, super elasticity refers to the internal stress within a certain deformation range increase along with the increase of strain, super elasticity can be divided into two categories, linear superelasticity and nonlinear hyperelastic.The stress-strain curve of stress and strain of the nearly linear relationship.Nonlinear hyperelastic refers to the Af above a certain temperature range, respectively, in the process of loading and unloading stress induced martensitic transformation and its inverse transformation results, so the nonlinear hyperelastic also called phase change pseudo elastic.Phase change of the nickel titanium alloy pseudo elastic can reach about 8%.Nickel titanium alloy of hyperelastic can change with the change of the heat treatment conditions, when the arch wire is heated to 400 & ordm;C above hyperelastic began to decline.
3, in the mouth temperature sensitivity: stainless steel wire and treatments of the CoCr alloy wire tooth orthopaedic basic is not affected by the influence of the temperature of the mouth.Treatments of the superelastic Nitinol wire tooth orthopaedic force along with the change of oral temperature changes.When the deformation must be.And correcting force increases as the temperature increases.On the one hand, it can accelerate the movement of the teeth, this is because the change of temperature in the oral cavity can cause capillary stimulation caused by rectification device stagnation of blood flow, blood flow to the sluggish rate so as to make the repair cells in the process of moving teeth get adequate nutrition, to maintain its vitality and normal function.Orthodontic doctors can't accurate control, on the other hand, or force measurement of oral environment correction.
4, corrosion resistance, studies have shown that the corrosion resistant properties of nickel and titanium wire and stainless steel wire
5, poison resistance: niti shape memory alloy special chemical composition, that is, this is a nickel titanium alloy atom, containing about 50% of the nickel, nickel and known have carcinogenic effect and promote cancer.General cases, the surface layer of titanium oxide ACTS as a barrier, the Ni Ti alloy has good biocompatibility.Surface layer TiXOy and TixNiOy can inhibit the release of the Ni.
6, treatments of the soft power: the teeth of commercial application of wire including austenitic stainless steel wire, cobalt - chrome - nickel alloy wire, nickel chromium alloy wire, alloy silk, gold wire and Australia to decide the titanium alloy wire.About the orthodontic correction of wire in the tensile test and three point bending test conditions of load - displacement curve.Nickel titanium alloy curve of unloading platform the lowest and most flat, it can provide most persistent treatments of the soft power.
7, good damping characteristics: caused by chewing and night molars for arch wire vibration, the greater the damage of tooth root and periodontal tissue.Through different attenuation experiment results, the study found the arch wire stainless steel wire vibration amplitude is larger than hyperelastic nickel titanium silk, super elastic nickel-titanium arch wire the initial vibration amplitude is only half of stainless steel wire, good vibration and shock absorption characteristics of the arch wire is important for the health of the teeth, and traditional arch wire such as stainless steel wire, tend to increase the root absorption.