There are usually two ways to cool steel sheets: air-cooled and water-cooled.
1. The high quality PPGI corrugated roofing sheet is immersed in a molten zinc bath to adhere to a thin layer of zinc to the surface. It is mainly produced by the continuous galvanizing process, that is, the coiled steel plate is continuously immersed in a zinc-plated plating tank to form a steel sheet; the alloyed color corrugated steel sheet. This steel sheet is also produced by hot dip, but immediately after it is discharged, it is heated to about 500°C to form an alloy coating of zinc and iron. This PPGI corrugated roofing sheet has good adhesion and weldability of the coating.
2. The low price color corrugated steel sheet can be divided into two types: in-line annealing and off-line annealing according to different annealing methods, and they are called the protective gas method and flux method.
PPGI corrugated roofing sheets are widely used in the industry. Some inferior galvanized sheets will affect the use of the products. How can we avoid some unqualified materials in our purchase process?
The hot dip galvanized steel coil for sale has many functions, but it also has its shortcomings, including easy to fall off, easy to scratch during construction, zinc particles, air knife streaks, exposed steel, mechanical damage, wave edge, dimensional mismatch, steel-based properties Bad, roller printing, etc.
There are many reasons for the galvanized layer falling off, including surface oxidation, the cold emulsified emulsion is too dirty, the protective gas dew point is too high, hydrogen flow is low, and oil evaporation is not enough, so it is necessary to observe galvanizing in the purchase. Whether the surface of the steel plate is intact.
dam liner/fishing farm/shrimp liner Hdpe geomembrane is actually very convenient and quick to lay, because when the material is purchased from the material factory, the main way of this material is cylindrical, as long as it is unfolded from one direction. Therefore, it is only necessary to control one direction when laying, and it is still necessary to pay attention to many problems when laying, so as to ensure the longest service life of the material to the greatest extent.
The function of the geomembrane when it is working, the main method of using this material is to lay it, but its functional properties can be analyzed from its corrosion resistance and high strength performance, filament geotextile First of all, its corrosion resistance makes it usable in many bad environments. It can also be used in the petrochemical industry, but its water resistance and elasticity make it possible to use the foundation protection.
The high quality cold rolled steel coil china: cold-rolled from ordinary carbon structural steel or low-alloy structural steel into a cold-rolled sheet with good surface quality and good punching performance. It is required to ensure that the cold bend and cup test is qualified for the raw materials of the automotive industry and the coated board.
Cold-rolled high-quality steel coil: mainly including various high-quality steel cold-rolled coils, the most commonly used carbon-structured steel sheets, especially cold-rolled steel sheets for deep-drawing are made of low-carbon high-quality steel 08Al cold-rolled coil steel according to surface quality. The three groups I, II, and III respectively indicate that the special advanced, advanced, and high finishing surfaces are classified into ZF, HF, and F grades according to the drawing level. According to the allowable deviation of the thickness of the steel plate, it is further divided into two grades A and B, which are widely used in the automobile tractor industry.
Cold-rolled steel coil: Excellent surface finish for household appliances such as automobiles, refrigerators, washing machines, industrial equipment, and various building materials. With economic development, cold-rolled steel coils have been called essential materials for modern society.
Diamond high quality 9'' grinding wheel machine is a kind of hardware and machinery product which is often used in modern industry. Generally speaking, the operation of the diamond grinding wheel machine needs professional training. So we must pay more attention to the operation of a diamond grinding wheel machine. Now the following are the major issues, so the small edition here for you to summarize as follows, hoping to help more people understand how to operate the diamond grinding machine and in the operation of the diamond grinding machine in the process of what needs attention.
Side grinding: In the daily use of grinding wheel machine, it is also necessary to classify the grinding wheel machine, but in the daily use process, many operators do not divide the type of grinding wheel, arbitrarily grinding the side of the wheel, which is a serious violation of safety operating regulations. According to the regulations, the grinding wheel with the circumferential surface as the working face is not suitable for side grinding. The radial strength of this kind of high quality 9'' grinding wheel is large, and the axial strength is very small. If the operator exerts too much force, the grinding wheel will break, even hurt people. This behavior should be prohibited in the actual use process.
Front operation: In daily use, many operators are accustomed to operating toward the grinding wheel, because this direction can be used, in fact, this behavior should be particularly prohibited in the operation of the grinding wheel. According to the operation rules, when grinding the workpiece with a grinding wheel machine, the operator should stand on the side of the diamond grinding wheel made in China and not operate on the front of the grinding wheel, so as to avoid grinding wheel flying out or grinding wheel breaking out and hurting people.
Force operation: In the use of the grinding wheel made in China machine, some operators, especially young operators, in order to grind faster, too much force, this is a very unsafe operation behavior. The flatness of any grinding wheel has a certain strength, so it is likely to cause the grinding wheel to break, or even fly out of injuries, is also a prohibited behavior.
Because the width of the 4.5 inches grinding wheel is large, the main pumping arm has larger elongation. Because the grinding width is large, so the grinding force, grinding power is also relatively large, the heat generated from grinding is also more.
In order to ensure the shape and position accuracy of the workpiece, it is required that the hardness of the 4.5 inches grinding wheel should be raised uniformly only in the circumferential direction, and the axial uniformity must be good, otherwise the uneven wear of the grinding wheel will affect the accuracy and surface quality of the workpiece.
After the grinding wheel is formed and dressed, the forming surface can be grinded to ensure the forming degree of the workpiece. At the same time, the cutting-in grinding mode is adopted, which is more efficient than the longitudinal reciprocating grinding.
Because of the above grinding characteristics, wide 4.5 inches grinding wheel grinding is suitable for grinding a large number of wall workpieces, such as spline shaft, motor shaft, twist drill, sewing machine under the axle, automobile and tractor drive shaft.
Grinding wheels in use should pay attention to the corresponding problems, but in the replacement time should pay attention to every detail, so as to reduce the problem in later use, so we should pay attention to these problems to ensure the use of results, what should be noted?
1.Frequently occurring validity problems, any long life grinding wheel has a certain validity period, in the validity period of use, it is qualified grinding wheel; beyond the validity period of use, not necessarily qualified grinding wheel;
2.Wear problems, the general provisions, when the China long life grinding wheel wear to the diameter of 10 mm larger than the chuck diameter should be replaced with new grinding wheel, can not save materials, on the use of excessive wear requirements;
3.Texture problems, in the course of use, if there is a crack in the local grinding wheel, should immediately stop using, replaced the new grinding wheel, so as to avoid the grinding wheel breakage injury accident;
The use of any grinding wheel for stainless steel has certain wear requirements, wear to a certain extent will be replaced by new grinding wheel. Above for the attention of the wheel replacement, we need to pay attention to, so as to use more smoothly in the future.
In cutting process, increasing the cutting performance and durability of ceramic high efficient metal abrasive disc cutter is attracting more and more attention. In the metal cutting process, because of chip deformation and friction, the cutting zone produces high temperature, and because of the different ceramic grinding wheel cutter and workpiece materials, forming the two poles of thermocouple and thermoelectric potential, resulting in direct current thermoelectric current. The thermoelectric flow can easily intensify the oxidation process of the surface of the grinding wheel and accelerate the abrasion of the grinding wheel.
Under certain conditions, the contact area between ceramic cheap metal grinding disc cutter and machine tool, workpiece and machine tool, and the contact area between the friction pair of machine tool itself will also produce thermoelectric emf-thermoelectric current. Thermomagnetic effect and electromagnetic effect will also occur in the cutting process. Thermoelectric emission-discharge phenomenon will also occur on the surface of high temperature contact area.
Thermoelectric current produced in the cutting process and other factors caused by the thermal current, and at the same time there is a local thermal current in the grinding tool workpiece within the limited contact area, which aggravates the wear of the grinding tool. In addition to the above-mentioned basic ways, there is a new way to improve the cutting performance and durability of ceramic grinding wheel cutter, that is, to eliminate and strengthen the thermal current effect of wear of ceramic China high efficient grinding disc cutter and try to cut off the thermal current loop.
What are the grinding characteristics of ultra-thin cutting wheels? What are the points for attention in the use of ultra-thin cutting wheels? The following is the introduction of Xiaobian: The ultra thin China long life grinding wheel is mainly used for precise grooving and cutting, and the deep and slow feed grinding method is adopted. It has the characteristics of large grinding depth, small feed speed, large contact area between grinding wheel and workpiece, narrow slit, high metal removal rate, high grinding accuracy, good surface quality and high material utilization.
The general laws are as follows: 1). The monolithic cutting blade grinding wheel is thin in thickness (mostly less than 0.5mm), small in diameter (20-100mm), fine in size, high in shape and position accuracy, light in weight, and generally used at high speed. The general speed is 5000-40000rpm.
2). Most of the matrix cutting grinding wheels are thick (0.5-2 mm), large diameter (100-200 mm), coarse grain size and low precision, which are generally used in the condition of low rotational speed and large cutting depth. The general speed is 3000-10000rpm.
3). Ultra-thin cutting grinding wheels use fine grain size, and generally the thinner the thickness of the abrasive grain size will be correspondingly fine, good surface quality. However, the finer the abrasive particle size, the lower the cutting sharpness, the lower the feed speed, so as to adapt to the machinability of abrasive particle size.
4). Ultra-thin cutting grinding wheel cutting depth is generally determined by the user according to the cutting parts, its cutting mostly adopts slow-feed grinding process, the depth of one cut to. In this way, because the grinding wheel for stainless steel is thin and the cutting conditions are poor (mostly 3 contact workpieces), it is difficult to heat dissipation, so it is necessary to increase (flow, pressure) on the cutting zone cooling.
5). It is suggested to increase cutting speed or decrease feed rate when cutting grinding wheel is immovable or workpiece breaks when it is used on the machine at the user's place. When cutting wheel is immovable or breaks after a certain period of use, it is suggested to cut the surface of grinding wheel with appropriate grain size of oil stone to adjust its sharpness.
6). The surface quality and cutting performance of workpiece are mainly related to the abrasive grain size of ultra-thin cutting grinding wheel. The finer the grain size, the better the surface finish. At the same time, it also has something to do with the factors such as workpiece material, hardness, cutting amount, machine condition, processing requirement and so on.
7)the ultra thin China long life grinding wheel has been trimming and sharpening before the factory is ready, so the user can use it directly. If the user needs further shaping, it is recommended to use green silicon carbide or white corundum oil, the particle size of the grinding wheel is 1-2 larger than that of the cutting wheel; if the user needs to further cut or use a section after cutting, it is recommended to use green silicon carbide or white corundum oil, the particle size of the cutting wheel is 1-2 smaller than that of the same size.
8)Cutting parameters are also generally related to the material to be processed, hardness, accuracy, processing requirements and so on. It is recommended that the best initial use in the user's original conditions to use, do not easily change the cutting parameters.
9)User's operating conditions are also the main factors affecting cutting performance, especially axial series, radial runout of machine tool spindle, flange parallelism, dynamic balance accuracy and so on, which directly affect the cutting accuracy of cutting grinding wheel.
High-speed cutting of all kinds of tool steel, ceramics, cemented carbide, thickness from 0.1 mm, its precision and thickness tolerance is very high. This series of products have the characteristics of high cutting precision, quick work efficiency and low material consumption, especially suitable for cutting high hardness steel, analyzing material cutting, sample cutting or precious metal, lithofacies, various crystal and ceramic slices, glass and alloy, semiconductor, integrated circuit board PCB, etc., widely used in mold manufacturing industry and steel Wood factory.
21.02.2019 04:38
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