2016年12月3日星期六
The function of some groups of stainless steel Rolling mill?
This stainless steel Rolling mill group contains from 12% to 17% Cr. If the Cr content is at the lower limit (12 ~ 13%) then we have to control the carbon content C is not exceed 0.4% to avoid creating too much chromium carbide. Because Chromium Carbide depleted Cr content in the alloy background and reduce corrosion resitance. If the Cr content is up to 17%, the amount of C can be as high as 0.9 ~ 1.1% to increase the mechanical properties (stiffness) and still remain corrosion resistance.
The suitable temperature for heat treatment of this steels Rolling mill is: 950 ~ 1100 ° C. The coolling environment may be oil or air (due to of high content of % Cr so it should be easy to fabricate). The Ram temperatures depends on the specific requirements but must pay attention to avoid brittle ram type II in the temperature of 350 ~ 575 ° C (by quenching in oil. If stainless steel was cooled slowly will forms Cr23C6 steel brittle and reduce the corrosion resistance).
Martensite stainless steel Rolling mill has a high corrosion resistance in freshwater environments, because of the passive effect of chromium so that it is not corrode in acidic HNO3 (but corrosive in other acid). This stainless steels with low carbon content (eg: grade 403 and 410 of U.S) is used for stainless steel jewelry, stainless
Ferrite stainless steel Rolling mill has a higher elastic limit than Austenite stainless steel but the plastic deformation is lower, so, they are suitable for the normal fabrication (rolling, drawing, typing , stamping, etc.). Corrosion resistance of them depend on chromium content. In order to limit the local corrosion (point corrosion), we have to increase the chromium content above 20% and better increase more 2% of Mo alloy to be used in the marine enviroment, seawater and acid.
Ferrite Stainless Steel 410 304 Stainless Steel Rolling mill Composite
Depending on the Cr content, ferrite stainless steel be divided into three groups:
The stainless steel Rolling mill group 1 contains about 13% Cr, has very little of carbon (<0.08%). Add ~ 0.2% Al will prevent the forming of austenitic when ignition and facilitate for welding. Group of this stainless steel is widely used in the oil industry.
The stainless steel group 2 contains up to 17% of Cr is a Ferrite stainless steel group and it is most widely using because they can replace the austenite stainless steel in some allow conditions. This group is not contain Ni so it should be much cheaper. This stainless steel group is used widely in HNO3 acid production industry, the food processing, the architecture decoration ... The main disadvantage of this group is difficult to weld, when the temperature exceeds to 950 ° C, the area near the weld becomes brittle and be corroded at the connection (This problem can be overcome by lower % C or adding more content of Ti into stainless steel).
The stainless steel group 3 contains Cr from 20 ~ 30% Cr (ex: 446, 446B) have a very high antioxidant properties.
Rolling mill is a mill or factory where ingots of heated metal are passed between rollers to produce sheets or bars of a required cross section and form.
2016年12月2日星期五
What are the features of the Use Steel Crystallizer?
Crystallization is the (natural or artificial) process where a solid forms where the atoms or molecules are highly organized in a structure known as a crystal. Some of the ways which crystals form are through precipitating from a solution, melting or more rarely deposition directly from a gas. Crystallization is also a chemical solid–liquid separation technique, in which mass transfer of a solute from the liquid solution to a pure solid crystalline phase occurs. In chemical engineering crystallization occurs in a crystallizer. Crystallization is therefore related to precipitation, although the result is not amorphous or disordered, but a crystal.
The crystallization process consists of two major events, nucleation and crystal growth which are driven by thermodynamic properties as well as chemical properties. In crystallization Nucleation is the step where the solute molecules or atoms dispersed in the solvent start to gather into clusters, on the microscopic scale (elevating solute concentration in a small region), that become stable under the current operating conditions. These stable clusters constitute the nuclei. Therefore, the clusters need to reach a critical size in order to become stable nuclei. Such critical size is dictated by many different factors (temperature, supersaturation, etc.). It is at the stage of nucleation that the atoms or molecules arrange in a defined and periodic manner that defines the crystal structure — note that "crystal structure" is a special term that refers to the relative arrangement of the atoms or molecules, not the macroscopic properties of the crystal (size and shape), although those are a result of the internal crystal structure.
The crystal growth is the subsequent size increase of the nuclei that succeed in achieving the critical cluster size. Crystal growth is a dynamic process occurring in equilibrium where solute molecules or atoms precipitate out of solution, and dissolve back into solution. Supersaturation is one of the driving forces of crystallization, as the solubility of a species is an equilibrium process quantified by Ksp. Depending upon the conditions, either nucleation or growth may be predominant over the other, dictating crystal size.
Many compounds have the ability to crystallize with some having different crystal structures, a phenomenon called polymorphism. Each polymorph is in fact a different thermodynamic solid state and crystal polymorphs of the same compound exhibit different physical properties, such as dissolution rate, shape (angles between facets and facet growth rates), melting point, etc. For this reason, polymorphism is of major importance in industrial manufacture of crystalline products. Additionally, crystal phases can sometimes be interconverted by varying factors such as temperature.
The crystallization process consists of two major events, nucleation and crystal growth which are driven by thermodynamic properties as well as chemical properties. In crystallization Nucleation is the step where the solute molecules or atoms dispersed in the solvent start to gather into clusters, on the microscopic scale (elevating solute concentration in a small region), that become stable under the current operating conditions. These stable clusters constitute the nuclei. Therefore, the clusters need to reach a critical size in order to become stable nuclei. Such critical size is dictated by many different factors (temperature, supersaturation, etc.). It is at the stage of nucleation that the atoms or molecules arrange in a defined and periodic manner that defines the crystal structure — note that "crystal structure" is a special term that refers to the relative arrangement of the atoms or molecules, not the macroscopic properties of the crystal (size and shape), although those are a result of the internal crystal structure.
The crystal growth is the subsequent size increase of the nuclei that succeed in achieving the critical cluster size. Crystal growth is a dynamic process occurring in equilibrium where solute molecules or atoms precipitate out of solution, and dissolve back into solution. Supersaturation is one of the driving forces of crystallization, as the solubility of a species is an equilibrium process quantified by Ksp. Depending upon the conditions, either nucleation or growth may be predominant over the other, dictating crystal size.
Many compounds have the ability to crystallize with some having different crystal structures, a phenomenon called polymorphism. Each polymorph is in fact a different thermodynamic solid state and crystal polymorphs of the same compound exhibit different physical properties, such as dissolution rate, shape (angles between facets and facet growth rates), melting point, etc. For this reason, polymorphism is of major importance in industrial manufacture of crystalline products. Additionally, crystal phases can sometimes be interconverted by varying factors such as temperature.
2016年12月1日星期四
Get to Know the Fundamentals of a Rolling Mill?
An extended product rolling mill is one of the most demanding programs for motor drives. The rolling process consists of transferring from a hot steel billet through a "rolling train". The modern-day rolling train includes numerous rolling stands arranged in an in-line setup. Every single rolling stand consists of a highest and a bottom roll, driven with a gear box by an electric motor. The rolls of the stands have contours or "grooves" machined into the rolls, so the hot billet transferring in between the grooves is lessened in size and shaped by each subsequent stand. Common motor sizes for modern-day mills is around 600kW to 1200kW for every single stand. Typically specific amount of stands are used depending on the size of the feed billet as well as the finished product. There is additionally a basic completing rate followed nowadays.
The tension in between each stand must be properly controlled, as the slightest change in tension will impact the shape of the item. Furthermore as the billet head end gets in each subsequent rolling stand, the performance drop must recover extremely quick, so as not have an effect on the tension control. The motor drives are managed by a sophisticated stream or stress or loop command program, with must take into account the design reduction of every stand, and the efficient roll groove size which is constantly changing because of roll wear and heat range changes.
As the hot billet passes through the rolling train it is processed, lowered in proportions, and lengthened with the mill stands. The item will then be transferred to a walking beam cooling base, via a superior speed switch method (braking slide/aprons). Scissors in the rolling train generate head and tail crops, and separate the material to suit the cooling base.
Drive Assortment
Due to the effect tons involved, the motors and drives should be chosen to allow for momentary high overloads. NEMA standard MG-1 specifies the temporary (1 min) overloads of at least 200 percent. In reality the actual demands may be dissimilar. Whenever the actual lots duty cycle is understood, the excess dimensioning of the motor and drive need to be inspected by seasoned rolling mill applications specialists using dimensioning program devices offered by the majority of drive and motor makers.
From experience it has long been revealed that in order to satisfy the tension control demands the motor speed must be managed to about less than 1 %. Fortunately numerous modern-day AC and DC digital drives can fulfill this static accuracy rating. The more essential requirements is the dynamic performance rating of the drive which is needed to lessen the rate drop from the bar head getting in each stand. The performance drop is affected by the inertia of the stand or gearbox or motor mix as well as the compelling efficiency of the drive. The ideal velocity fall must be restricted to a certain quantity of percentage. Frequently it is recommended to for a rolling mill to mix different suppliers of gearbox, motors and drives to achieve the optimum combo of system inertia and vibrant efficiency.
2016年11月25日星期五
A Panacea for casting machine for steel making Defects?
casting machine for steel making is a technology wherein non-ferrous metals are subject to high pressure and temperature to get the required mold cavities. One of the steps in the process is jet cooling system of core pins. In die casting, issues arise such as shrinkage porosities, soldering around core pins and leakage of pressure during the process and so on. Hence, the industry requires a cutting edge technology based solution to come up with a defect free casting system. Cooling thus provides an instant solution that results in high-end casting quality and also provides better life and efficiency of dies. The ancillary advantage is that even the equipment used in die casting gives better output. A number of research and development activities were undertaken to get the desired results. Micro analysis of poor casting quality was a major concern, in-spite of taking utmost care. As a solution for such issues, the industry has been coming up with unique methodologies and one such trial is jet cooling machine also known as core pin cool machine in India.
The casting machine for steel making is designed to work in synchronization with the casting cycle so as to eliminate or atleast reduce the instances of die casting issues/rejections. The latest models of jet cooling machines come with customized touch panel type operation circuit to suit the needs of smaller units of die casting systems. The tube can be inserted easily in the small diameter cooling channel in a thin core pin. Variants of the tube include screw type, O-ring and packing types. The high-end technology enables the selection of option and cooling time and controls the same. The jets cooling machines runs into life by connecting the machine to the power port and integrate it with die casting machine and the media of coolers such as water and air. Especially, the jet cooling machine is cost effective for die casters with 4 core pins or lesser. With storage and space congestions in small plants, the plug and play solution provided by jet cooling machines comes handy. Ease of maintenance, reduced noise pollution and lesser space for installations are other advantages of the advanced jet cooling machines. The jet cooling system has enabled the die casting of small diameter core pins, which was hitherto not possible. The jet cooling system is thus being used worldwide with little variations in technology to suit individual machine requirements.
casting machine for steel making customized jet cooled core pins to customer specification and very important for long life of the cooled core pin.
The casting machine for steel making is designed to work in synchronization with the casting cycle so as to eliminate or atleast reduce the instances of die casting issues/rejections. The latest models of jet cooling machines come with customized touch panel type operation circuit to suit the needs of smaller units of die casting systems. The tube can be inserted easily in the small diameter cooling channel in a thin core pin. Variants of the tube include screw type, O-ring and packing types. The high-end technology enables the selection of option and cooling time and controls the same. The jets cooling machines runs into life by connecting the machine to the power port and integrate it with die casting machine and the media of coolers such as water and air. Especially, the jet cooling machine is cost effective for die casters with 4 core pins or lesser. With storage and space congestions in small plants, the plug and play solution provided by jet cooling machines comes handy. Ease of maintenance, reduced noise pollution and lesser space for installations are other advantages of the advanced jet cooling machines. The jet cooling system has enabled the die casting of small diameter core pins, which was hitherto not possible. The jet cooling system is thus being used worldwide with little variations in technology to suit individual machine requirements.
casting machine for steel making customized jet cooled core pins to customer specification and very important for long life of the cooled core pin.
What are the benefits of steel making?
Steel making is the process for producing steel from iron ore and scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon are removed from the raw iron, and alloying elements such as manganese, nickel, chromium and vanadium are added to produce different grades of steel. Limiting dissolved gases such as nitrogen and oxygen, and entrained impurities (termed "inclusions") in the steel is also important to ensure the quality of the products cast from the liquid steel.
Steel making has existed for millennia, but it was not commercialized until the 19th century. The ancient craft process of steelmaking was the crucible process. In the 1850s and 1860s, the Bessemer process and the Siemens-Martin process turned steelmaking into a heavy industry. Today there are two major commercial processes for making steel, namely basic oxygen steelmaking, which has liquid pig-iron from the blast furnace and scrap steel as the main feed materials, and electric arc furnace (EAF) steelmaking, which uses scrap steel or direct reduced iron (DRI) as the main feed materials. Oxygen steelmaking is fuelled predominantly by the exothermic nature of the reactions inside the vessel where as in EAF steelmaking, electrical energy is used to melt the solid scrap and/or DRI materials. In recent times, EAF steelmaking technology has evolved closer to oxygen steelmaking as more chemical energy is introduced into the process.
Steel making has played a crucial role development of modern technological societies. Cast iron is a hard brittle material that is difficult to work, whereas steel is malleable, relatively easily formed and a versatile material. For much of human history, steel has only been made in small quantities. Since the invention of the Bessemer process in the 19th century and subsequent technological developments in injection technology and process control, mass production of steel has become an integral part of the world's economy and a key indicator of technological development.The earliest means of producing steel was in a bloomery.
We are a steel machinery manufacturer in China, is professional in steel machinery with years's experience. We can supply the whole production line, from induction furnace, CCM and rolling mills with high quality and competitive price.
Steel making has existed for millennia, but it was not commercialized until the 19th century. The ancient craft process of steelmaking was the crucible process. In the 1850s and 1860s, the Bessemer process and the Siemens-Martin process turned steelmaking into a heavy industry. Today there are two major commercial processes for making steel, namely basic oxygen steelmaking, which has liquid pig-iron from the blast furnace and scrap steel as the main feed materials, and electric arc furnace (EAF) steelmaking, which uses scrap steel or direct reduced iron (DRI) as the main feed materials. Oxygen steelmaking is fuelled predominantly by the exothermic nature of the reactions inside the vessel where as in EAF steelmaking, electrical energy is used to melt the solid scrap and/or DRI materials. In recent times, EAF steelmaking technology has evolved closer to oxygen steelmaking as more chemical energy is introduced into the process.
Steel making has played a crucial role development of modern technological societies. Cast iron is a hard brittle material that is difficult to work, whereas steel is malleable, relatively easily formed and a versatile material. For much of human history, steel has only been made in small quantities. Since the invention of the Bessemer process in the 19th century and subsequent technological developments in injection technology and process control, mass production of steel has become an integral part of the world's economy and a key indicator of technological development.The earliest means of producing steel was in a bloomery.
We are a steel machinery manufacturer in China, is professional in steel machinery with years's experience. We can supply the whole production line, from induction furnace, CCM and rolling mills with high quality and competitive price.
2016年11月11日星期五
Know More About The Process Of Heat Treating?
Heat treating is field that many of us are unfamiliar with, but it is a very important part of creating items we use every day. The process has played a part in our military, influenced industry and makes our lives easier thanks to the tools created because of this process. Altering the properties of any metal needs the application of some heat, or removal of heat using the technique of quenching. Treating the metal with heating and cooling can change the following properties to different levels :- ductility, hardness, softness, stress and tensile strength. To attain these properties, one or the other of the following treatments can be used – tempering, hardening, stress relieving, annealing, normalizing and quenching. Cooling rates from the high furnace temperature are also an important part of this type of treatment. Leaving the heat treated part in furnace to cool at a controlled rate is the slowest general cooling rate.
Generally, fast cooling involves some type of liquid and is known as Quenching. Each liquid provides a different cooling rate, so it is important that the correct quenching liquid is used to achieve proper heat treating cooling levels to avoid breaking. The other methods of cooling include forced air or gases such as nitrogen. A combination of heating and cooling operations applied to an alloy or a metal in solid state to obtain the required conditions and properties. Heating for the hot working is excluded from the meaning of definition here. The first method of the heat treating process normally suits for low carbon steel and is mainly passed on cold rolled steel such as the wire drawn steel. This method tends to improve the properties such as ductility and hardness which otherwise makes the process difficult. Heat treating a material can change the size of the crystals to grow or shrink.
Additionally, Heat Treating the heat treating process can cause different phases to become more common - that is, different arrangements of the molecule. Ultimately, heat treatment achieves the desired metallic characteristics by growing the different phases to required grain and concentration size. Generally, in the carbon steels, different phases are characterized by the presence and concentration of carbon. Generally, the term heat treatment is used for increasing the strength of materials like steel and alloys as it greatly affects the mechanical properties such as ductility, strength, hardness, toughness and wear resistance of the materials. Anyhow, it can also be used to change some manufacturing defects such as it can help in improving machining, improving the permeability, restoring ductility of alloys after a very difficult working procedure. So, it can be considered as a permissive manufacturing process that not only helps the other manufacturing processes, but also improves the performance of product by increasing it's strength and other required properties of the product or metal.
Steel rolling mill machinery an important equipment in steel industry?
In early times when there were no computers in this world and all the works were performed with physical efforts of men has now turned this technology so advanced that rarely any kind of work is optimized without machines and computers. Different types of machines are used for different kinds of work. Business over this world is divided into so many sections serving for different purposes. So today we'll discuss about the steel rolling mill machinery of India. With the advancement in technology people are inventing new things that are making their task easier and easier. Machines are one of those things. It has been categorized on the basis of their sizes, work type and costs. They are used for making steel, metal sheets etc.
Do you know what is metal and how it is made? Metal is an electropositive element which has shiny surface. It has good qualities and more efficiency. It is a good conductor of electricity and can be melted or fused in any shape by using high processed heating methods. We can make out of metal sheets by passing out them through the rollers en the machines are categorized under two categories. Hot rolling mill machinery & cold rolling mill machinery process carried out through steel rolling mill machinery. You may or may mot know that each and every metal has its own recrystallization temperature.
If the temperature of the metal is above its recrystalization temperature then it is termed under hot rolling mill machinery process and if the temperature of the metal is below the recrystalization temperature of the metal then the process is called as cold steel rolling mill machinery. With the help of these processes we are able to make sheets, plates and foils out of these. Sheets from the metal are used for construction, transport and aerospace. These sheets are used as well for airliner components. It is genuinely known that the plate form is more efficiently used than the sheet form as it is thinner than it but still both are used for same applications. Plate form of steels is commonly used for auto motive industry and foil form is thin so more flexible and used for packaging. It is also used for foil stamping. Besides this it has a wide use over the electronic sectors of industry for shielding. Moreover machinery of India has proved its worth over mechanical industry also. The unit that uses the steel rolling mill machinery is known as steel rolling mill plants. Some of the items like I-beams, hot strips, steel rods, plates and h-beams are generally used in steel rolling mill plants.
If you an owner of steel rolling mill plant and are in need of this steel rolling mill machinery then buy it from a well named company or you can simply refer to the site named machinesindia.com this site will enable you to reach the dealer who deals in this machine. This site also offers various product categories such as hand tools, pharmaceuticals machinery, machine tools, roll forming machinery, plant and machinery, oil mill machinery and lots more. If you are looking for expanding your business then be a part of this website. Not only the outcomes of business with the development of steel rolling plants rolling mill machinery, will you also find other mechanical equipments, and machinery.
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