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מאי 2018  (20)
Inventory of materials used on high-speed rail
25/05/2018 03:59
susanchen
Inventory of materials used on high-speed rail(1)


The significance of China's high-speed rail exports is not only the “sea-going” of individual industries, but the “going out” of the entire industrial chain. Although the current market size is small, once it is recognized by overseas markets, it will reshape the global brand image made in China. , driving the development of the upstream and downstream sub-sectors of the industry chain? Today, Xiao Bian took everyone to look at the high-speed rail materials?
For high-speed railways, higher requirements are placed on the strength, fatigue performance, light weight, and processability of new materials. The application of new materials is mainly based on the following aspects:
Railway vehicle
Stainless steel is mainly made of nickel-chromium austenitic stainless steel. Because of its high corrosion resistance and aesthetic characteristics, it is used in Japan, the United States, and the former Soviet Union. Under the premise of ensuring strength and rigidity, the thickness of the skeletons such as beams and pillars is limited by 3.2 to 6.0 mm of ordinary steel is reduced to 1.0 to 1.5 mm, which can reduce weight by about 40%. In the early 1960s, Japan took the lead in developing stainless steel vehicles. Its light weight, energy saving, and no need for painting resulted in a significant economy. Benefits: More than 5,000 stainless steel vehicles currently account for more than 10% of all buses?
The main application: stainless steel body because it is not easy to solve the problem of air tightness of the body, only for the production of 20km / h speed class car body and the car carrying and decorative parts.

Aluminum alloy
Aluminum has a low density of only 2.7 (a light metal), about 1/3 that of steel. Because the surface of aluminum is easily oxidized to form a dense and stable oxide film, the corrosion resistance is good. Aluminum has good castability. Aluminum has a low melting temperature, good fluidity, and is easy to manufacture parts with various complex shapes. The aluminum alloy still maintains the characteristics of light weight, but its mechanical performance is obviously improved.
main application:
The first is as a force component;
The second is as a door, window, tube, lid, shell and other materials;
The third is as a decoration and thermal insulation material? Aluminum alloy is easy to process and has a high degree of heat dissipation?
In particular, the engine part of the vehicle is particularly suitable for the use of aluminum alloy materials. Almost entirely here is a world of aluminum alloys. In addition, the processing technology of aluminum alloys is diverse and versatile.
In the long term, the price of aluminum alloy is moderate, while the higher price of aluminum makes the manufacturing cost of vehicles increase. However, due to aluminum alloys making vehicles lighter, the weight of vehicles brings about an increase in transport capacity, energy consumption, and maintenance. Reduced costs? According to statistics, for every 10% reduction in the weight of vehicles, fuel can be saved by 8%. Aluminum products can achieve 100% recycling when scrapped and recycled. Recycling aluminum can reduce energy consumption by 95%.
As early as the 1950s, some of the world’s more advanced countries began to use aluminum profiles to manufacture railway vehicles, including the United States, Canada, Japan, Russia, Germany, and France. At present, aluminum alloys have been widely used in domestic high-speed rail cars. Experts in the industry pointed out that aluminum alloy materials must be lightweight in high-speed trains with a speed of 300 km/h or more, aluminum rails should be used in all 350 km train cars except the chassis, and CRHI? CRH2 is currently used in China EMUs. CRH3?CRH5 four types, in addition to CRHI type body is stainless steel, the other three kinds of EMU body are aluminum alloy material?
In recent years, attempts have been made to manufacture car body skeletons from aerospace materials such as magnesium alloys and Chin alloys, which weigh only 66% of that of aluminum alloys.
Composite materials
Composite materials have been applied to vehicles, and their usage has been increasing, which represents the future development trend. Fiber-reinforced resin matrix composites (FRF) because of high specific strength (stiffness), fatigue resistance, corrosion resistance, heat insulation, and flame retardant can be designed. Such advantages as strong nature, the United Kingdom, Japan, and Germany began to be applied to non-structural parts in the 1960s, and they are now increasingly used in various structural parts such as the use of fiberglass reinforced plastics and aramid fiber-reinforced epoxy at the front ends of cars and front ends. Resins, etc. Currently, in western Europe, the composite materials used in the manufacture of railway vehicles are classified according to the types of fibers, and glass fibers account for 58%. Aramid fibers account for 20%, carbon fibers account for 20%, and others account for 2%. Types, polyester accounted for 35%, ethylene carbonate accounted for 22%, epoxy resin accounted for 21%, phenolic resin accounted for 15%, modified acrylic resin accounted for 4%, other 3%?

Bogie
The bogie frame is a particularly important high-strength component. It concerns the safety of the entire vehicle. The turret must meet the requirements of safety, operating comfort, wear-resistance and easy maintenance.
The use of high-quality carbon steel, low-alloy, low-carbon, high-strength steel, and weather-resistant steel manufacturing frameworks have recently been the focus of research on polymer composites and aluminum alloys.
Vehicle interior equipment
Vehicle interior equipment and equipment mainly include decorative plates, toilets, washrooms, seats and water tanks, etc., mainly aluminum alloy and polymer materials, such as decorative plates laminated with aluminum alloy on a layer of non-combustible fiber-reinforced plastic, toilets ? League washing room? Seats and tanks also take into account the health and corrosion resistance, but also non-combustible is better?
Wheel system
In addition to sufficient strength, toughness, and wear resistance, wheel and rail materials must also be resistant to scratches and peeling.
As far as the line is concerned, the main characteristics of high-speed railways that distinguish them from ordinary railways are large curvature radius, high strain rate, light axial weight, large traction, small wear on rails, and relatively prominent fatigue damage. Therefore, the selection requirements for rail materials are relatively high. high?
For rail materials, European railways have been conducting research on alloy rails. For example, non-heat-treated Cr-Mo alloy rails have the ability to withstand short-wave wear in addition to high cyclic softening resistance. They are the future rails. One of the key choices for materials? In addition, efforts should be made to strengthen and toughen the rail steel, and to develop the full-length heat-treated steel rails, rare earth steel rails and new rails for noise reduction and vibration reduction.
At present, 347 Stainless Steel Bar being studied abroad are better than pearlite steels in anti-peeling performance, but they are still in the experimental stage. In order to reduce weight, Germany is studying composite wheels, that is, wheel center adopts FRP, and then put on steel wheels and tires. ?
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Three major causes of oxidation in stainless
24/05/2018 04:09
susanchen
Three major causes of oxidation in stainless steel

Three major causes of oxidation often occur in  309 Stainless Steel Pipe:
1, the production process causes: This is one of the reasons leading to the production of steel products oxidation, from the production process and product characteristics, the formation of a thin oxide film on the surface of the product is to avoid the occurrence of oxidation of the basic process, but also steel products Different from other main characteristics of iron and steel products, but due to the lack of production process or negligence, the performance of the oxide film is incomplete and discontinuous. The oxygen in the air directly reacts with some elements of the product to undergo a redox reaction, resulting in The product showed oxidation.
2, the ratio of product ingredients Reasons: Some manufacturers in order to reduce production costs, thereby reducing the proportion of some important elements such as chromium, nickel, and increase other such as carbon content, this is not strictly in accordance with the product model, product characteristics The production of ingredients is not only to reduce the quality of the product, for example, when the content of chromium in the 304 stainless steel tube is insufficient, it not only affects the corrosion resistance and formability of the product, but also exists in the chemical industry, equipment and production industries. Potential product quality safety hazards; at the same time, it also affects the appearance and oxidation resistance of the product.
3. Man-made reasons: This is also one of the reasons for the oxidation of some of the products most frequently encountered by consumers when using stainless steel products. Some consumers improperly use the products in their use and maintenance, especially  310 Stainless Steel Pipe   products used in the food and chemical equipment industry. Occurrence of man-made oxidation is high. For the oxidation of man-made steel products, it is necessary to have the correct knowledge of product use and to carry out reasonable and effective maintenance and maintenance on a regular basis, thereby reducing the oxidation caused by improper use of man-made materials.

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Ten characteristics of stainless steel
23/05/2018 04:05
susanchen
Ten characteristics of stainless steel combination tank


304 Stainless Steel Pipe combination water tank, SUS304 stainless steel ball faceplate combined welding water tank is a new type of water tank utilizing new technology and new technology. The design of the stainless steel composite tank bearing plate is reasonable. It makes full use of the tensile characteristics of stainless steel metal materials and has the purpose of decompressing the pressure. The average force of all the plates is uniform, the appearance is elegant and there is no deformation, and the integrity is good. Compared with other types of tanks, the following Raised strengths:

First, stainless steel composite tank bearing design
The ball-panel water tank takes full advantage of mechanics and evacuates the pressure of the water, preventing large circular tanks from being inconvenient to process and occupying large defects. At the same time, the stainless steel combination tank also prevents the problem of unequal bearing capacity of the square tank, and utilizes the largest bearing on the circular arc surface to greatly increase the bearing capacity and the anti-seismic performance of the tank itself.

Second, the overall structural design of stainless steel combination tank
The inner lacing structure of the ball-panel water tank adopts a strictly designed mesh structure and is supplemented with diagonally-stretched ribs at specific angles, so that the various parts of the water tank are united together to form an integral body. When there is water in the water tank, the inner lacing It plays a supporting role to prevent the problem of easy deformation of the external reinforcement ribs.

Third, the stainless steel combination tank hygiene pollution-free
Imported high-quality SUS304-2B stainless steel plate, the polishing surface will not allow dirt to accumulate, which facilitates the cleaning of the water tank in the future. The opacity prevents the harmful algae such as Chlorella from breeding, which is suitable for modern people's high demand for drinking water and is suitable for advanced The property can be used as a publicity point for real estate developers to increase sales of properties.

Four, stainless steel combination tank life
SUS304 stainless steel water tank is suitable for storing water or physical properties similar to water medium. Medium temperature: 0~900C; ambient humidity: 0~98%. Because the material itself has a strong corrosion resistance, its service life is much longer than ordinary materials, but also due to the use of high-tech argon arc welding process, so that the entire welded structure prevents the assembly tank rubber strips from aging and causing leakage. The common problem of leakage does not need to be exchanged in the future, and the service life can reach 40 years.

Five, stainless steel combination tank is particularly suitable for making large-tonnage water tank
Large-tonnage tanks have large capacity and require high skill in inner lacing; pressure is high, and the requirements for tensile and shear resistance of the tank materials are also high. Stainless steel combination tanks in the form of ball plates and net-shaped lacing are used for tensile strength. Shear can meet the needs of large-capacity water tanks.

Six, stainless steel combination tank is simple and easy to assemble
The stainless steel ball-panel water tank adopts the thin-walled stainless steel plate, and at the same time, it also has the advantages of the assembled water tank. The use of a standard plate form to the site welding assembly does not affect the construction of the structure. The stainless steel combination water tank has the advantages of high assembly speed, strong integrity, light weight, and no additional load on the building.

Seven,  304L Stainless Steel Bar combination tank shape aesthetic
The stainless steel combination water tank adopts the film coating process in the mechanical processing, transportation, and assembly process, so that the scratches caused by friction are greatly reduced during the processing, and then the equipment is torn to the film after the equipment is assembled and the equipment is protected. , The product is bright and elegant.

Eight, stainless steel water tanks cheap
The design of the ball plate and the structure of the net-shaped inner reinforcement are combined with a stainless steel water tank, which can effectively reduce the wall thickness of the water tank. Thin-walled stainless steel plates are used, so that the cost is greatly reduced and the performance is better. The customers use the lower price High quality equipment.

Nine, stainless steel tank insulation structure is good
In order to match the curvature of the ball panel, a special polyurethane insulation board in line with the plate type is specially made. The glass fiber reinforced plastic cover is covered with a white enamel coating. Its appearance is elegant, and it is clean and generous, and the heat preservation function is much better than other materials. product.

Ten, stainless steel combination tank cleaning
Stainless steel composite water tank ball panel's own bright surface is not easy to attach dirt, stainless steel combination tank is easier to clean than other materials, in addition, the ball panel form in the lowest point of the bottom of the tank drain pipe, so that the sewage more easily discharged, will not form stagnant water, easy Cleaning management.

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Stainless steel process performance and test
22/05/2018 04:12
susanchen
As we all know, there are many kinds of stainless steels, different properties, and different manufacturing processes. The process of 304 Stainless Steel Pipe is complex and requires high performance and technical requirements. Stainless steel blind rivets are made of high quality Korean KOS imported stainless steel (with excellent hot and cold processing and forming properties, strength, elongation, good area reduction, corrosion resistance, etc.). Hengfeng Rivet has industry-leading production equipment and world-leading detection equipment. It is produced strictly in accordance with customer drawings or samples. Strictly control the specifications of materials, size tolerances, tensile shear performance, etc. The sampling qualification rate is as high as 98%, giving you the most cost-effective rivet products. Stainless steel process performance and test methods are divided into the following categories:

First, the tensile test. Tensile test is mainly used to test the toughness and plasticity of stainless steel materials. Through the test of tensile test, it ensures the plasticity and forming performance of stainless steel materials.

Second, bending test. Bending test is an effective method to detect the bending resistance of stainless steel and coating. In the bending test, defects of stainless steel materials can be found in time and repaired in time. The bending test is one of the important inspection steps in stainless steel manufacturing and provides an important basis for the anti-bending performance of stainless steel.

Third, the cupping test. Cupping test is an effective method to test the stamping properties of stainless steel. In some application fields, there are strict standards for the stamping of stainless steel materials, such as mechanical manufacturing, automotive shipboard, etc. If the stamping performance is not closed in the process of mechanical forming, it will easily lead to cracking of stainless steel plates, which will seriously affect the product quality. Therefore, cupping test is indispensable in the production of stainless steel.

Fourth, the impact test. The impact test is similar to the cupping test and is an important step in testing the impact toughness of 304L Stainless Steel Bar. The impact test is the collision of the stainless steel material through the external force of the equipment. In this process, the toughness of the material itself can be effectively released, and the impact test has the characteristics of reliability and effectiveness.

Through the above four detection methods, it is enough to prove that stainless steel products meet the requirements and can meet the needs of different applications.

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learn about the common metallic Alloying agent
21/05/2018 04:16
susanchen
metal is largely iron and carbon alloyed with certain extra factors. The procedure of alloying is used to exchange the chemical composition of metal and improve its homes over carbon metal or regulate them to fulfill the requirements of a selected utility.

benefits of metallic Alloying marketers:
special alloying elements each have their own impact at the residences of metal. some of the houses that may be progressed through alloying consist of:


Stabilizing austenite: factors together with nickel, manganese, cobalt, and copper boom the temperatures variety in which austenite exists.
Stabilizing ferrite: Chromium, tungsten, molybdenum, vanadium, aluminum, and silicon will have the effect of reducing carbon's solubility in austenite. This consequences in an increase in the amount of carbides inside the metal and reduces the temperature variety in which austenite exists.
Carbide forming: Many minor metals, along with chromium, tungsten, molybdenum, titanium, niobium, tantalum and zirconium, form strong carbides that - in metallic - increase hardness and energy. Such steels are often used to make high-pace metallic and warm work tool metal.
Graphitizing: Silicon, nickel, cobalt, and aluminum can decrease the stableness of carbides in steel, selling their breakdown and the formation of free graphite.
lower of eutectoid concentration: Titanium, molybdenum, tungsten, silicon, chromium, and nickel all lower the eutectoid concentration of carbon.
growth corrosion resistance: Aluminum, silicon and chromium shape protecting oxide layers on the surface of steel, thereby shielding the metal from similarly deterioration in sure environments.
commonplace metallic Alloying agents:
beneath is a listing of generally used alloying elements and their impact on metal (fashionable content material in brackets):


Aluminum (zero.ninety five-1.30%): A deoxidizer. Used to restriction the boom of austenite grains.
Boron (0.001-zero.003%): A hardenability agent that improves deformability and machinability. Boron is delivered to fully killed metallic and only desires to be delivered in very small quantities to have a hardening effect. Additions of boron are only in low carbon steels.
Chromium (zero.five-18%): A key element of stainless steels. At over 12 percent content, chromium substantially improves corrosion resistance. The metallic additionally improves hardenability, energy, response to warmness treatment and wear resistance.
Cobalt: Improves strength at excessive temperatures and magnetic permeability.
Copper (zero.1-0.four%): most usually observed as a residual agent in steels, copper is also introduced to provide precipitation hardening houses and increase corrosion resistance.
Lead: despite the fact that without a doubt insoluble in liquid or solid metallic, lead is on occasion brought to carbon steels through mechanical dispersion for the duration of pouring with a purpose to enhance machinability.
Manganese (0.25-13%): increases strength at high temperatures by means of putting off the formation of iron sulfides. Manganese additionally improves hardenability, ductility and wear resistance. Like nickel, manganese is an austenite forming detail and can be used in the AISI 200 series of Austenitic  440c stainless steel sheet rather for nickel.

Molybdenum (zero.2-5.zero%): found in small quantities in stainless steels, molybdenum increases hardenability and power, specially at high temperatures. often used in chromium-nickel austenitic steels, molybdenum protects against pitting corrosion caused by chlorides and sulfur chemical compounds.
Nickel (2-20%): another alloying element vital to 310s stainless steel sheet, nickel is added at over 8% content to excessive chromium chrome steel. Nickel will increase electricity, impact strength and sturdiness, while additionally enhancing resistance to oxidization and corrosion. It also increases longevity at low temperatures when introduced in small amounts.
Niobium: Has the advantage of stabilizing carbon by way of forming hard carbides and, so, is often located in excessive-temperature steels. In small amounts, niobium can substantially growth the yield strength and, to a lesser degree, the tensile energy of steels as well as have a mild precipitation strengthening the effect.
Nitrogen: increases the austenitic balance of stainless steels and improves yield power in such steels.
Phosphorus: Phosphorus is regularly delivered with sulfur to enhance machinability in low alloy steels. It additionally provides strength and increases corrosion resistance.
Selenium: increases machinability.
Silicon (zero.2-2.0%): This metalloid improves energy, elasticity, acid resistance and consequences in large grain sizes, thereby, leading to greater magnetic permeability. due to the fact silicon is used in a deoxidizing agent inside the manufacturing of steel, it's miles almost constantly found in a few percent in all grades of metallic.
Sulfur (0.08-zero.15%): introduced in small quantities, sulfur improves machinability with out resulting in warm shortness. With the addition of manganese hot shortness is in addition reduced due to the fact that manganese sulfide has a better melting factor than iron sulfide.
Titanium: Improves both strength and corrosion resistance whilst proscribing austenite grain length. At zero.25-0.60 percent titanium content, carbon combines with the titanium, allowing chromium to stay at grain limitations and resist oxidization.
Tungsten: Produces strong carbides and refines grain length to be able to boom hardness, specially at excessive temperatures.
Vanadium (0.15%): Like titanium and niobium, vanadium can produce stable carbides that growth energy at high temperatures. by selling a best grain shape, ductility can be retained.
Zirconium (0.1%): will increase strength and boundaries grains sizes. energy may be extensively accelerated at very low temperatures (below freezing). metal's that encompass zirconium as much as approximately zero.1% content can have smaller grains sizes and withstand fracture.

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a few questions about stainless steel
18/05/2018 04:54
susanchen
a few appropriate questions about stainless steel

Q: I just switched from nonstick pans to stainless steel pans, however now the whole lot I cook sticks on there, until i use copious quantities of oil. What am i able to do to make cooking with these a little simpler?

Editor: the solution isn't in adding more fat, however as a substitute when you add it. chrome steel desires to be preheated earlier than you add fats to the pan. It would not want to be blistering, but you ought to be capable of experience the warmth radiating from the pan when you keep a quit it. once it is hot, you then upload the fat. It should spread across the pan fast and begin to shimmer in a rely of seconds.

And take into account, in case you're searing meats, face up to the urge to agitate them until they have got very well browned. as the proteins constrict, they may release their grip on the pan and also you ought to be able to flip them with minimal sticking.


Q: How do you take away the fishy flavor/scent from a 316 stainless steel sheet pan after frying/cooking fish in it?

Editor:generally, I don't have a hassle, however it is took place to me approximately twice within the previous couple of years. what's bizarre is on one occasion, it came about some makes use of when I cooked the fish. i am perplexed due to the fact I commonly don't have this issue except for some random instances.

Q: My mother just gave me all the old forged iron and the All-Clad stainless-steel skillets from my early life. I recognise a way to easy the cast iron and even season it and smooth and season the internal of the stainless steel. My trouble is this; The out of doors of the stainless-steel is blackened from the numerous, a few years of use.

How do i get it these smooth? I simply got a ultra-modern range the day earlier than she gave them to me. i am afraid to take a seat them on my burner, however I not like non-stick pans.


Q: Can all of us help? i have deep scratches at the door of my 304L Stainless Steel Bar  refrigerator. Does every body have any advice on a way to treatment that?

Editor: First i would advise attempting stainless steel cleaner to see if a good way to help get the scratches out.


Q: How do I smooth a brand new stainless steel or brushed stainless steel sink? i've scratches and marks on it already.


Editor: chrome steel is actually susceptible to choosing up a few scratches over the years, but you can frequently reduce the scuffs with an awesome stainless steel purifier.
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Distinguish the quality of stainless steel
17/05/2018 04:12
susanchen
Distinguish the quality of 15-5 PH Stainless Steel Bar color plates from four aspects
As the application of stainless steel color plate decoration in construction is becoming more and more extensive, there are more and more processing factories for coloring stainless steel coating. So this year in foreign countries and China's Hong Kong and Macao regions more popular stainless steel color plate trendy metal plate architectural decoration methods. The use of stainless steel color plates for architectural decoration in China has only been popular in recent years, and is more common in coastal economically developed areas such as Guangzhou and Shenzhen. Although there are also in the Mainland, it is not yet very common. Because of the popularity and price of such stainless steel color plate decoration materials, it has caused many bad businesses to substitute for inferior and cut corners. This not only causes great losses to many consumers, but also seriously damages the color stainless steel. Market environment. How do you choose a high quality stainless steel color plate?

Here is a simple way to identify:
1. First, distinguish the material of the metal plate material
The most commonly used materials for 13-8 Stainless Steel Bar color plates in the market today are the 6 types of stainless steel such as 201, 304, 31. The best materials for corrosion resistance are 316, the worst material is 201, and their price is different. Larger, so many businesses use the inferior material 201 instead of 304,316. Or the use of water plating coloring process to replace the vacuum ion plating coloring process of stainless steel color board sales to customers, making a lot of architectural decoration and decoration works to install color stainless steel titanium plate, mirror panels and other surface color fade, rust or even It is a broken situation. Therefore, when purchasing the inspection process, it is necessary to ensure that the material of the plate is the material that was originally discussed, and the different material of the stainless steel can be distinguished by the detection solution.
2, stainless steel surface color coloring process
The same stainless steel coloring process is also one of the important factors that determine the price level. The water plating coloring process is obtained by using a chemical liquid soaking to obtain a color compared to the vacuum plating coloring process. The difference is that the vacuum plating coating layer has a stronger bonding force with the workpiece surface. The hardness of the film layer is higher, the wear resistance and corrosion resistance are better, and the performance of the film layer is also more stable, such as the color stainless steel titanium plate, the gold-plated surface of the water-plated titanium plate gives the feeling that it is sprayed up; Vacuum plating does not produce toxic or contaminating substances. Water plating will result in the pollution of wastewater. Compared with vacuum ion plating, the color is not so pure and there will be shelling, but the price is much lower than vacuum plating.
Since both the stainless steel color plate material and the coloring process are generally difficult to distinguish from the naked eye, a professional with a lot of experience is required to be able to distinguish the quality of the product. Therefore, it is necessary to look for a stainless steel color plate decoration material. A professional and reputable processing plant should be purchased. Do not delay the renovation project for a small amount of money.
3, observe the metal surface
Because the stainless steel color plate is mainly used for building decoration works, the decorative appearance of the surface is particularly important. Therefore, during the inspection, it is necessary to carefully inspect and observe the surface, whether there is color difference between the plates, uniform coloring, good color, scratches, trachoma, peeling water marks, etc. Especially if you want titanium plates, etc., the surface is a mirror effect. If the quality is good, the surface should have no head flower and horseshoe prints, and the brightness is high. Of course, the price is relatively high.
4, the quality of the film
After the stainless steel color plate product processing is completed, a protective film is applied on the surface, and this film can ensure that the surface finish is not contaminated, or the protection does not scratch the hard object. However, if it is a poor quality protective film for a long time, it will appear powdery, it is difficult to tear or tear and stick a lot of glue on the surface of stainless steel, causing the metal surface is not only difficult to see difficult to remove. Customers in the inspection are able to tear open the larger area to see the quality of the film; and after the completion of the renovation project, tear off the film as soon as possible, especially the outdoor decoration project, after the installation is best to tear immediately Film.
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Several kinds of stainless steel
16/05/2018 04:12
susanchen
Several kinds of stainless steel simple identification method, you get a few?
316L Stainless Steel Rod is our common kind of high-grade alloy steel, such as stainless steel cutting tools, stainless steel kitchen

 utensils, and stainless steel building materials in our daily life. It has the characteristics of stainless steel, acid resistance, high temperature resistance, wear resistance, and generally non-magnetic austenite. Below we all take a look at several simple methods of identification of stainless steel:

In the case of unknown steel species, we can determine whether it is stainless steel or not based on the physical and chemical properties inherent in the product (including solids, remnants, waste, etc.) using simple instruments. A specific method of stainless steel.

It should be pointed out that sensory identification can not distinguish specific steel (species) numbers, but can basically distinguish three major categories of chromium stainless steel, chromium-nickel stainless steel (SUS303, 304) and chromium-manganese nitrogen stainless steel (200 series). The identification methods are as follows:

1, the color of the identification

Pickled stainless steel, the surface color of silver and white smooth: chromium nickel stainless steel color silver white jade; chromium stainless steel color white slightly gray shiny weak; chromium manganese nitrogen stainless steel color and chromium nickel stainless steel is slightly lighter. The surface color of stainless steel that has not been pickled: Chrome-nickel steel is brownish white, chrome steel is brownish black, and chromium-manganese nitrogen is black (these three shades are heavily oxidized). Cold-rolled unannealed chromium-nickel stainless steel with silver-white surface.

2, with copper sulfate identification

Method is to remove the oxide layer on the steel, put a drop of water, rubbing with copper sulfate, if the color does not change after wiping, usually stainless steel; such as changing the purple: non-magnetic high manganese steel, magnetic general steel Or low alloy steel.

3, using the magnet to identify

Magnets can basically distinguish between two types of stainless steel. Because the chromium stainless steel can be attracted by the magnet in any state; the chromium nickel stainless steel is generally non-magnetic in the annealed state, and after the cold working, some are magnetic. However, manganese-rich steels with higher manganese content are non-magnetic; chromium-nickel-nitrogen-based stainless steels have more complex magnetic properties: some are non-magnetic, some are magnetic, and some have a non-magnetic vertical surface and a magnetic surface.

Therefore, although magnets can basically distinguish between chromium stainless steel and chromium-nickel stainless steel, they cannot correctly distinguish some special-purpose steel grades, let alone distinguish specific steel grades.

For steel products of special nature, we need to adopt the following three methods for identification.

1)grinding flower identification

Grinding the flower is to distinguish the stainless steel from the grinder and observe its spark. Such as sparks are streamlined, and there are more dense section of the flower, that is, higher manganese containing high manganese steel or manganese nitrogen steel; if no flowers are chromium steel or chromium nickel stainless steel.

2)annealing method

Chromium-nickel stainless steels that are cold-worked, if they are magnetic, may preferably be red-hot in the fire to allow them to cool naturally or be added to water (annealing). In general, after annealing, the magnetism will be significantly reduced or completely disappear. However, some chromium-nickel stainless steels, such as Cr18Ni11Si4AlTi steel and Cr21Ni5Ti steel, because the steel contains more ferrite elements, a considerable part of its internal structure is ferrite. Therefore, it is magnetic even in the hot working state.

3)Chemical qualitative identification

The chemical qualitative method is a method to identify whether the magnetic stainless steel contains nickel. The method is: deep solution of small pieces of stainless steel in aqua regia, dilute the acid solution with clean water, add ammonia water, and then gently Inject nickel reagent. If there is a red fluffy substance floating on the liquid surface, it means that stainless steel contains nickel; if there is no red fluffy material, it means that stainless steel is free of nickel. (However, since the amount of nickel contained in stainless steel is low, it is generally only a few percent, and the nickel content is not easily revealed or determined. Generally, it is necessary to master the standard sample test several times beforehand.

The above methods of identification show that: In order to identify stainless steel with a sinusoidal tube, it is necessary not only to use several methods for comprehensive tests, but also that the test results can only determine certain types of stainless steel, and it cannot be determined which kinds of alloy elements and specific contents are included in the steel. Therefore, the method of sensory identification is currently extremely imperfect, and some may be erroneous. There are many physical phenomena. They only know it, but they do not know why it needs to be discussed further.

The best way to correctly distinguish the 321 stainless steel rod grades is to inquire into the investigation and study of the relevant processing units, consult their material managers and workers, learn about the steel grades of the materials used, and carefully look at the steel marks on the steel and consult the original. Information, etc., This is the fundamental method to correctly distinguish stainless steel grades and quality.
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Japan Develops Technology for Injection of Hyd
15/05/2018 04:27
susanchen
As a means to reduce the ratio of the blast furnace reducing agent, an effective way is to improve the reduction efficiency, reduce the heat loss, use metal iron, and blast furnace injection of high hydrogen-containing reducing agents, such as injection waste plastic (CnHm) and natural gas. (CH4). In order to make effective use of these reducing agents having a high hydrogen content, it is possible to perform the injection at the same time as the conventional coal injection operation (PC). However, the influence of hydrogen on the combustibility of pulverized coal and the influence on the reducibility of raw 347 Stainless Steel Tubing in the blast furnace can be understood quantitatively.
To understand the effect of gaseous reducing agent (CH4) on the combustibility of solid reductants (pulverized coal, waste plastics), combustion experiments were performed using a hot state model. The particle size of the experimental pulverized coal is -74, which accounts for 80% of the experimental solid reducing agent, and the particle size of the waste plastic is about 4 mm. The experimental air supply temperature was 1200°C. In order to maintain the theoretical combustion temperature (TFT) in front of the tuyere, oxygen-enriched air was supplied during the air supply. The injection conditions are divided into two conditions: the solid reductant alone and the solid reductant and CH4 are simultaneously injected. Further, the relationship between the excess oxygen ratio (ratio of oxygen in the supply air and the amount of oxygen required for complete combustion of the injected reducing agent) and the gasification rate of the solid reductant combustion was investigated. The combustion gasification rate is based on the carbon (C) balance in the thermal model and is experimentally derived. It is the total value of the solid reducing agent.
Compared with when the  316 Stainless Steel Pipe reducing agent is burned alone, the combustion gasification rate at the time of simultaneous injection with CH4 is 4% at the time of pulverized coal injection, and can be increased by about 5% when pulverized coal and waste plastic are simultaneously injected. This is because the gas-reducing agent CH4, which has a high combustion rate, will immediately start burning after blowing, increasing the temperature in the furnace, allowing the pulverized coal and plastic to heat up and evaporate, and promoting the combustion of volatile components and the combustion of solid components. Combustion gasification reaction. The increase of the combustion gasification rate can reduce the amount of unburnt powder. Therefore, these factors can help to reduce the accumulation of charge in the hearth center dead column and the lower part of the furnace to avoid deterioration of the gas permeability of the lower part of the furnace.
According to the load softening test, the effect of hydrogen in the reducing gas on the reduction behavior of the sinter was investigated. As the hydrogen concentration increases, it can be seen that at the same temperature, the reduction rate will increase, the shrinkage rate will decrease, and the pressure loss will decrease slightly. This is because hydrogen can accelerate the reduction rate of the sinter, and the amount of unreduced FeO decreases before reaching the softening melting temperature region. That is, since the retention of the FeO-containing slag in the softening and melting layer is reduced, voids in the layer can be secured.
The injection volume of the commercial gas was set to 30 kg/t. In order to keep the TFT constant, the amount of oxygen enrichment was adjusted. Regarding air permeability, although the upper part of the furnace is basically the same as before the injection, the lower part of the furnace body is greatly improved. This is because the above reduction is promoted and the voids in the soft-melt band are ensured. By utilizing this air permeability, the blast furnace utilization factor can be increased. In addition, under certain production conditions, the effect of reducing CO2 emissions has increased by about 2.3%.
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Development of Stainless Steel Pipe Technology
14/05/2018 03:55
susanchen
2 Localization of process technology and equipment
China's 17-7 stainless steel sheet pipe production process, technology and equipment development path is: a full set of introduction - the key part of the introduction - digestion and absorption - independent innovation.
At present, China has a variety of international-level seamless pipe units, including: Ф159-Ф508mm three-roll mill pipe unit, the largest diameter Ф720mm cycle rolling unit, the largest diameter Ф1500mm pipe jacking unit, 1600 tons - 68,000 tons hot extrusion Pressure tube unit and so on. Whether it is introduced or domestically manufactured, the average level of equipment has reached the international level. It is worth mentioning that in 2009 Inner Mongolia "Baojiji" domestically produced 36,000 tons vertical extrusion machine, extruding the first large-caliber thick-walled seamless steel pipe to break the history that China could not produce large-caliber (thick-walled) extruded steel pipe. In 2012, Hebei Hongrun 50,000 tons vertical extrusion machine was born; in 2015, Kangtai, Qinghai, the largest pressure of 68,000 tons of extrusion and die forging double function heavy-duty extrusion unit put into production. These are the results of China's independent innovation, which has made China's independent production of high-alloy, hard-to-deform, large-diameter, thick-walled seamless steel tubes a reality. In addition to import substitution, it has also become an international market. The development of extrusion units in China has contributed to the domestic production of 17-4 stainless steel sheet pipes (thick-walled) in China.
Since the 1990s, China’s welded pipe industry has entered a peak of development. We have introduced various types of advanced welded pipe units. Through digestion and absorption and independent innovation, we have developed welded pipe units similar to the imported models, which has greatly promoted our country’s welded pipe technology. With the improvement of technology and equipment manufacturing technology, the technology and equipment of some welded pipe enterprises are already at the international advanced level. Especially for stainless steel welded pipe units, both the number of newly-built units and the production capacity are greater than seamless stainless steel pipes. At present, China's stainless steel production capacity is mainly concentrated in private enterprises.
Although China will not build a large number of new steel pipe units in the near future, it is necessary to carry out research and development improvement, accumulation of knowledge, and experience on weak links for existing equipment upgrades and equipment maintenance. The transformation will further increase the level of steel pipe equipment manufacturing. China's steel pipe technology and equipment are changing from "acquisition to transmission", and China's steel pipe equipment manufacturing industry is moving from manufacturing to creation.

3 Innovation of major process technologies and equipment

The stainless steel pipes in China have developed rapidly in the past 30 years and have made great breakthroughs in production and technology. The introduction of a number of technologically advanced technological equipment has resulted in an increase in production capacity. In addition, hot-rolled (perforated) seamless stainless steel pipes have been manufactured. The use of continuous casting round billet production, which is also one of the achievements made in the past 30 years.
Since 1986, it has begun to introduce foreign equipment and technology to produce stainless steel pipes. So far, there are many stainless steel pipe production lines, but in terms of the size of steel pipe units, more than 80% are small and medium-sized units, which is due to market demand.
What is proud of is that in the past 30 years, China has achieved remarkable results in the hot extrusion tube field. Table 1 shows the major stainless steel tube extrusion press equipment in China.

In short, although China's stainless steel pipes have achieved certain achievements in terms of process technology and equipment innovation, there are still gaps in equipment automation, technological innovation capabilities, product quality assurance, and production efficiency compared with foreign advanced levels. The production technology and production equipment of stainless steel tubes in China are both advanced and backward. At present, some stainless steel tubes used in some important fields in China, such as stainless steel high-pressure boiler tubes, aerospace tubes, and nuclear power plant tubes, still need to be imported. Change this situation as soon as possible to promote the progress of stainless steel production in China.

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