Zhejiang Balford Mechatronics Co., ltd focus on difficult stamping & deep drawing. Main product: motor housing and difficult custom deep drawn stampings.

  • What is the relationship between the cracking of stainless steel tensile parts?

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    The radius of the punch fillet is too small and too sharp, which is prone to cracks. Therefore, the method of repairing the mold is to increase the fillet as much as possible and polish it if the product specifications allow, and be careful not to be too sharp. The use of special drawing oil can also play a good anti-crack effect, but it should be noted that the lubricant is only suitable for the working surface of the die, and the lubricant should not be in contact with the punch, because the punch and the blank surface will produce good cracks. friction, preventing the material from sliding, cracking and thinning.

    Stainless heat-resistant steel and austenitic stainless steel are more common, and these two materials are used as examples. The specific reasons are as follows:

    Austenitic stainless steel: Austenitic stainless steel produces delayed cracks due to its own structure. Austenitic stainless steel has a large degree of work hardening. After stretching, in addition to the residual internal stress caused by cold working, the austenitic structure is There is also some martensitic transformation in the mouth, so the mouth of the mouth should be prevented from cracking. In order to eliminate residual stress and eliminate martensite structure and make it undergo phase transformation at high temperature, taking 304 as an example, the annealing temperature of austenitic stainless steel is 1010~1050℃. The mouth of the extension is annealed, and the faster one is high-frequency annealing.

    For cylindrical drawn parts, when the diameter is greater than or equal to 0.8 and the diameter is greater than or equal to 300, annealing treatment is required. Of course, if cracks occur when the aspect ratio is less than 0.8, annealing should be arranged immediately.

    Ferritic stainless steel: no phase change occurs after stretching. The main reason for product cracking is residual stress, which can ensure safety. From experience, for cylindrical drawn parts, when the diameter is greater than or equal to 0.8 , when the diameter is greater than or equal to 300, annealing treatment is required. If the height-diameter ratio is less than 0.8, cracks will appear, and annealing should be arranged immediately.

    The above content is related to what is related to stainless steel cracking, and what problems will occur in the production process. In fact, many experienced workers can prevent it in advance. Only by reading and analyzing more can a lot of waste can be avoided. I hope the above content is correct. Readers help.

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  • What are the factors that affect the processing quality of metal drawing parts?

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    1. Material selection

    Various materials have different tensile properties. The ratio of blank diameter to punching diameter is the ultimate drawing speed. Stainless steel ranges from 1 to 2.2, carbon steel from 2.15 to 2.5. In addition to heat treatment, stainless steel materials can also be subjected to secondary stretching, but unlike carbon steel materials, stainless steel materials generally cannot be stretched like the first time except for heat treatment. Stretch like that. Stainless steel pipe needs to be one to two times larger than carbon steel. In general, double-acting deep-drawing hydraulics are preferred.

    Second, choose lubricating oil

    The choice of lubricant should consider two factors. A scratch-resistant and friction-reducing oil film must be provided. Plus, it’s easy to remove all of it once the deep flush is done. It can contain chlorinated or sulfurized oils or waxes, heavy washes or deep soaps. Deep drawing is a method of forming cylindrical or box-shaped hardware from a ring or metal die screwed into a thin sheet of metal material. Commonly used gold materials are stainless steel, aluminum, iron, copper, etc. Metal deep flush products are available in different heights.

    If there is a deviation in the stretch, what is the reason?

    For blanking parts, if the punching size deviates, the specific reason is that there is a problem with the mold structure design or product material. Also, there may be a problem with the device. In this regard, we should investigate one by one to find out the real cause, fundamentally solve the problem, and prevent it from happening again.

    The dimensional accuracy of drawn hardware parts refers to the difference between the actual size and the design size of the stamping part. The difference is small and the precision is high. Ideally, the punched and die edges are the same size, and the punched and punched edges have the same size. In fact, due to the force on the workpiece during the blanking process, a certain elastic deformation will occur.

    After blanking, the elastic recovery of the workpiece leads to the mismatch of the dimensions of the blanking part, the die edge part, the punching part and the punching part, which affects the precision of part of the metal blanking. In addition, there are many factors that affect the dimensional accuracy of stamping parts, such as blanking gap, mold manufacturing accuracy, material properties, stamping part thickness, shape, size, etc.

    The most important thing is the blanking gap. Because the gap between the punch and the mold is too large, the stretching effect on the material is large during the blanking process, so the tensile deformation is large. Due to the rebound after blanking, the size of the blanking part is reduced, and the size of the punched part is increased. If the gap is too small, the material will be compressed due to the extrusion of the punch and die. Due to the elastic recovery of the material, the size of the stamping part increases and the size of the stamping part decreases.

    The above content involves the processing of hardware products, and the dimensional accuracy of the final stamping parts is also related to the characteristics and thickness of the material. However, for the general stamping parts manufacturer, due to the small variation in material thickness, such conclusions and explanations can be drawn. I hope the above will be useful to readers.

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  • What are the standards and requirements for the hardness testing of mold materials in mold processing plants?

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    Hardness is usually the basis for measuring the heat treatment quality and performance of molds, and hardness is an important performance indicator of mold materials and finished molds. The stress state of the hot mold during the working process is very complex. For example, the hot mold is generally subjected to alternating stress in an alternating temperature field. Therefore, the mold should prevent the mold from becoming soft or plastic, and maintain its shape and size in a long-term working environment. Precision remains unchanged. Usually, the hardness of the finished product and the cold mold are usually 59-60HRC, and the hot work mold is often used around 48HRC.

    Wear resistance is an important performance indicator of the finished mold. During the molding process, the metal moves relative to the surface of the mold cavity, causing the cavity surface to wear, and the mold size, shape, precision and surface roughness to change and fail. Wear resistance mainly depends on the heat treatment of the mold, especially the surface heat treatment. The main basis for evaluating the wear resistance of the mold is the hardness.

    The test hardness test is mainly aimed at three situations, namely the hardness test of the die steel material, the heat treatment hardness test of the semi-finished mold, and the surface hardness test after the heat treatment of the mold surface.

    Steel mold materials are mainly forged steel plates, steel blocks or steel bars, which are generally supplied in an annealed state. Some plastic steel molds also provide pre-hardening (quenching and tempering treatment), and users can directly process them into molds without subsequent heat treatment. According to different steel types, die steel can be divided into carbon tool steel, alloy tool steel and high-speed tool steel. The Chinese standard specifies the factory hardness requirements of various die steels, and tests the annealing hardness and quenching hardness of the steel. Mattel Leeb hardness tester is widely used, with fast detection speed and simple operation, and the detection value can be automatically converted into Brinell hardness value, so it has been widely used.

    The die steel material that has been machined must be quenched and tempered, and can be made into a finished die after fine grinding and polishing. It is more important to test the hardness of the quenched and tempered mold, because the hardness of the material is a very important quality index at this time, which determines the service life of the finished mold to a large extent. Quenched and tempered mold materials require a Rockwell hardness tester to measure HRC Rockwell hardness. Molded products are required to have the best comprehensive mechanical properties, not only sufficient hardness, but also certain toughness. Hardness and toughness are a pair of contradictions. In order to achieve reasonable toughness and make the mold have higher hardness, the most Optimal hardness values ​​will be limited to a fairly small range, typically 2-4 HRC units.

    There are great difficulties in hardness testing of finished and semi-finished products. There is no more ideal solution. Only a small number of molds that are small in size and weight can be moved to a benchtop Rockwell hardness tester for testing. For finished products, the Leeb hardness tester is a solution to hardness testing semi-finished products and Leeb hardness before converting to HRC on Rockwell hardness. At present, the commonly used method in the mold industry is to use a Leeb hardness tester to measure hardness, and the Mattel Leeb hardness tester is the most widely used in the mold industry.

    As mentioned above, the reasonable hardness range of finished and semi-finished molds is narrow, and the Leeb hardness tester cannot meet this precision requirement. But this is also the current status of the mold industry, and there is no better solution. For surface carburizing, nitriding or laser quenching treatment, the surface hardness of the mold with surface hardening treatment should be tested. When the thickness of the infiltrated layer exceeds 0.8mm, the hardness of HRC can be directly measured by a Rockwell hardness tester. When the thickness of the carburized layer is 0.6-0.8mm, the A scale of the Rockwell hardness tester can be used. The test pressure A=60kg (the C-level test force value is 150kg), which can press a shallow indentation on the surface of the mold, so that the hardened layer will not be penetrated, and the hardness test is relatively accurate. HRA hardness measurements are easily converted to HRC hardness values ​​by looking up the table. If the thickness exceeds 0.1mm, a surface Rockwell hardness tester can be used for thinner carburized or nitrided layers. Ground Rockwell hardness tester is only 15kg, 30kg or 45kg. For example, when a surface Rockwell hardness is 60HRC, the surface Rockwell hardness value is 90.6HR15N, and the indentation depth is equal to (100-90.6)X0.001mm=0.009mm, in this case, it is almost difficult to distinguish. Therefore, the surface Rockwell hardness tester can also test the finished product, and the obtained hardness value can also be converted into HRC hardness value.

    For die steel, hardness is the most important property. To account for other properties, such as toughness, its optimum hardness range is narrow. Therefore, how to use the Mattel portable hardness tester to test the hardness of the mold quickly and accurately is of great significance to the mold manufacturing and use units. It can improve the quality of mold products, improve the mold manufacturing process, and prolong the service life of the mold.

    In fact, the hardness of the mold processing material is not bad, only the wrong material is used in a specific area. Therefore, designers must fully understand the properties of various materials, and carefully test the materials, and carefully test the materials to study the influence of various factors on the performance of molded products. Hopefully the above will be useful to the reader.

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  • What are the parts of the design and processing of metal stamping parts?

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    1. Stamping parts must meet the requirements of product use and technical performance, and be easy to assemble and maintain.

    2. Where permitted, stamped parts must help improve material utilization, reduce material types and specifications, and use low-cost materials.

    3. In order to simplify the mold structure and optimize the number of processes, the stamping parts must be simple, and there is a simple punching step, that is, to complete the processing of all parts. Try not to use other processing methods that are conducive to stamping operations, easy to organize, and achieve mechanized and automatic production to improve labor productivity.

    4. The dimensional accuracy and surface roughness of sleeve pressing parts should be minimized.

    5. The design of stamping parts should be processed with existing equipment, process equipment and process flow as much as possible to improve the service life of stamping dies.

    Due to the wide application of metal stamping dies, the popularity of stamping parts and changes in processing technology, there are many factors affecting the performance of metal stamping dies. The production process of metal stamping dies mainly includes:

    1. The production process of metal stamping dies includes

    (1), raw materials

    (2), mold

    (3), punch

    There are many kinds of stamping materials, and stainless steel is the most widely used. Most stamped products are made from steel sheet materials through stamping dies. Stamping hardware products can be seen everywhere in our lives.

    2. What are the metal stamping dies?

    1. Furniture hardware accessories

    2. Home appliance stamping parts

    3. Home kitchen supplies

    4. Automobile stamping parts

    5. Body

    6. Chassis

    7. Auto booster

    8. Car brake pads

    9. Radiator

    The above molds are all made by stamping. The material requirements for stamping parts are high, such as hardness, strength, tensile, corrosion resistance, surface quality and plasticity, and the accurate thickness is considered.

    With the rapid development of the industry, the variety of molds continues to increase, and the mold design is more and more accurate and complex. The qualification rate of stamping parts is closely related to whether the mold design is reasonable. The forming, surface quality, dimensional tolerance and product qualification rate of stamping parts are related to the design of the die process structure. Simply put, the process technology of a product is usually a single process. Multiple process, progressive or compound tooling is available if product processing license is available.

    Stamping equipment is the most widely used hydraulic press in the factory. Punch is divided into ordinary punch and high-speed punch. Generally speaking, if most of the processes can solve production problems with high-speed punching or multiple processes, the key factors in making qualified products are advanced stamping equipment and die technology.

    The above is the relevant content of the design and processing of metal stamping parts. Under the premise of ensuring factors, the correct use and maintenance of metal stamping dies is also to improve the quality of stamping dies. Because metal stamping dies will shorten the service life of stamping dies if they are used and maintained improperly, regular inspection of abrasive tools can make the processing of stamping parts more accurate. I hope the above will help readers.

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  • Design principles and service life of stamping and drawing parts

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    With the continuous progress of science and technology and the continuous improvement of the level of economic development, machinery manufacturing and drawing parts processing enterprises are also developing rapidly and with high quality. It is no exaggeration to say that there are several or dozens of mechanical products that use some kind of high technology every day. Needless to say, the application of high technology in the machinery industry has made stretching products more intelligent in appearance and operation, breaking people’s impression of being clumsy and rigid. Philosophically speaking, quantitative change leads to qualitative change, and the theoretical goal is to prove that any object is a system and that no single cell or component can represent its integrity. Therefore, when people begin to pay more and more attention to the highlights of high-tech, we cannot ignore the bracket structure composed of various high-precision tensile parts, because without a strong supporting platform, all high-tech is on paper.

    Due to the wide range of use, wire drawing is widely used. But it’s troublesome to actually find it. Most companies have a stable supply of parts, and most follow the principle of proximity. Otherwise, it will affect their production. Only a few products eager to succeed can post order information on the website. Such stretched parts manufacturers themselves should have their own very skilled industrial products, better concentrated in a certain industry, can improve their proficiency and technical level, once the order is received, there is price, quality, delivery time. Therefore, hardware tie rod manufacturers should position themselves and not blindly pursue too much. It can widely use automobiles and electronic pull rods as a professional R&D and production, which improves the technical level in this field and forms an advantage in the industry. Only in this way can the hardware stretched parts have their own foothold.

    1. The design of expansion joints should follow the following principles

    1. When ensuring normal use, the designed telescopic parts should minimize the dimensional accuracy level and surface roughness, which is conducive to the interchangeability of products, reducing waste and ensuring the stability of product quality.

    2. The designed drawing parts should be as conducive to the use of existing equipment as possible, and the process equipment and processes will help prolong the service life of the stamping die.

    3. The designed tensile parts must conform to the use and technical performance of the product, and are easy to assemble and maintain.

    The main processing products are: stainless steel cover plate, stainless steel products, stainless steel seasoning bottle cap, metal stamping parts, tension parts, plugs, lighting accessories, non-standard hardware processing. Applicable to: electronics, electrical appliances, sports equipment, automobiles, packaging, machinery parts, food and other industries.

    In addition to reasonable mold structure, high machining accuracy, good heat treatment effect and correct selection of punch, etc., the service life of drawing stamping parts. In addition to the punch installation accuracy and other factors, the correct use and maintenance of the mold is also a link that cannot be ignored. During this process, attention should be paid to:

    (1) Before installing and using the drawing parts, the dirt should be strictly checked, and whether the guide rail sleeves and molds of the drawing parts are well lubricated.

    (2) After the cutting edge of the pull-out punch and the concave die are worn, they should be stopped and sharpened in time, otherwise the wear degree of the cutting edge of the die will be rapidly expanded, the wear of the die will be accelerated, and the quality of the punching part and the life of the die will be reduced.

    (3) While ensuring the life of the punch, the die spring should be replaced regularly to prevent the spring from fatigue damage and affect the use of the punching part.

    The above is the relevant content about the design and service life of stamping and drawing parts. Generally speaking, the drawing process and die, drawing device and material constitute the three elements of deep drawing. Only when they are combined with each other, a deep-drawn part can be obtained. Which link has a problem will also affect the processing quality of the drawn part. Hope the above content can be helpful to readers.

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  • What are the causes of product wrinkling and how to prevent it?

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    1. Analysis of the causes of wrinkling of tensile parts

    The way to avoid wrinkling is to ensure that the mold can hold down the material during the stretching process and to ensure a reasonable speed of movement of the sheet. If the sheet moves too fast when the product is stretched, it will cause wrinkling; on the other hand, if the sheet moves too slowly, it will cause the stamping to crack.

    1. Select reasonable pressing equipment

    When selecting the pressing equipment, the pressing equipment compresses the deformed part of the blank, and has a significant effect on the pressing material to avoid the flange part from arching and wrinkling. Press material should be appropriate. The pressing equipment is divided into two types: elastic pressing and rigid pressing. Elastic equipment is suitable for shallow drawing and rigid equipment is suitable for deep drawing.

    2. Reasonable selection of drawbeads

    Setting drawbeads on the binder surface is a useful method to control deformation resistance. The drawbead can well adjust the movement of the material, so that the material movement resistance of each part in the drawing process is uniform, so that the amount of material flowing into the cavity meets the needs of the appropriate parts, and avoids wrinkling and cracking. For curved stretched parts with messy shapes, especially those with small flanges, drawbeads should be set to increase the radial tensile stress of stretching and control wrinkling; the setting direction of the drawbeads is in the radial direction. The part with less stress, that is, the part where the sheet is easy to move. For parts with smaller flanges, some materials (process supplementary materials) can be appropriately added in order to set tensile ribs, and this part can be removed when trimming. For drawn parts with large difference in drawing depth, the draw bead should be set in the part with less material feed, so that too much material in this part can be arranged to be pulled into the cavity of the die to avoid wrinkling.

    2. Analysis of the causes of wrinkling of tensile parts

    There are many reasons for the wrinkling of the stretched parts during the stretching process, the main reasons are as follows:

    1. The drawing depth of the stamping part is too deep, which causes the sheet to move too fast during the feeding process, causing wrinkles.

    2. The R angle of the die of the stamping part is too large during the stretching process, which leads to the fact that the punch cannot press the material during the stretching process, resulting in the sheet material moving too fast and causing wrinkles.

    3. The pressing ribs of stamping parts are unreasonable, the pressing ribs are too small, and the direction is incorrect, which cannot effectively prevent the sheet material from moving too fast, causing wrinkling.

    4. The pressure of the ejector is too small, so that the stamping parts are not formed completely and wrinkle is formed.

    The above is the relevant content about the reasons for the wrinkling of stamping products. Of course, the wrinkling of products may also be due to problems with the parameters in the production process, and the parameters need to be redesigned. There are many reasons for product wrinkling. To prevent the cause of wrinkling, we can also check the origin.

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  • What are the requirements for die processing of metal stamping parts?

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    Stamping parts are mainly formed by stamping with the help of metal or non-metal plates under the action of a press. The main features are as follows:

    1. Main features of stamping parts

    (1) Stamping parts are made by stamping when the consumables are small. The parts are light in weight and good in rigidity. After plastic deformation, the internal structure of the metal is improved, and the strength of the stamping parts is significantly improved.

    (2) The dimensional accuracy of the stamping parts is high, the size of the stamping parts is uniform with the same die, and the interchangeability is good. General assembly and use requirements can be met without machining.

    (3) During stamping and forming, since the surface of the material is not damaged, the surface quality is good, and the appearance is smooth and beautiful, which provides convenient conditions for surface treatment such as spraying, electroplating, and phosphating.

    Dies used for stamping parts are usually specialized. Sometimes, a complex part requires several sets of molds to machine and shape. In addition, the mold manufactures high-precision, technology-intensive products. Therefore, only large-scale production of stamping parts can fully reflect the advantages of stamping processing, so as to obtain better economic benefits. However, there are also some problems and deficiencies in the stamping process. It is mainly manifested as noise and vibration during the stamping process, and operator accidents often occur. However, these problems are not entirely caused by the stamping process and the die itself, but are mainly caused by traditional stamping equipment and backward manual operations.

    In the stamping production process of the metal stamping factory, our dies have life after repeated processing losses, so what are the main factors affecting the life of the die?

    Second, the main factors affecting the life of the die

    1. Forming: During the use of the stamping die convex and concave die, the shape deformation occurs, which changes the geometric shape of the processed product parts, thereby affecting the dimensional accuracy and shape requirements of the processed parts. This situation is just the opposite of the fracture situation, mainly because the quenching hardness of the convex and concave dies is not enough during heat treatment, or because the quenching hardness layer is too shallow, the convex and concave dies are geometrically deformed when they are stressed.

    2. Broken: The convex and concave die are suddenly damaged, broken, and cracked during use. Since the die is the part of the die that is subjected to high die pressure during the punching operation, the die protrusion will break during the punching process. The main reason is: improper heat treatment (the quenched hard layer is too deep), such as If the design gap is too small, it will cause the mold to bulge and the die to be damaged, broken and broken. Punch and concave dies are broken, and some are partially damaged, which can be used after repairing, while some are damaged to a large extent or cannot be repaired.

    3. Wear: The die is raised, and the wear caused by frequent friction between the die and the processing material for a long time. Therefore, the long-term friction between the convex and concave dies between the materials to be processed results in a large number of and long-term punching, so that the burr of the punched parts is too large (the gap is too large), and the gap between the convex and concave dies is too small. The main reason for the wear of convex and concave molds. For example, the convex and concave die edges become blunt, and the edges and corners become gardens.

    4. Bite: The gap between the convex and concave dies is unevenly adjusted and assembled, and the adjacent edges of the convex and concave dies bite each other, resulting in gnawing on the edges of the convex and concave dies. If the position of the convex and concave dies is deviated during assembly, the gap is not uniform, and when the unguided die is installed, the gap between the convex and concave dies is not adjusted properly, causing bulges and the concave dies to bite and damage each other.

    The above is the relevant content of metal stamping mold processing. Due to the guarantee of the mold in the metal stamping process, the size and shape of the metal stamping parts can reach the effect of micron precision, and in many cases, the surface quality of the stamping parts will not be damaged, so that the characteristics of the metal stamping parts become stable and interchangeable. Hope the above content can be helpful to readers.

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  • What are the technical requirements for common automotive stamping die processing?

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    1. Characteristics of vehicle stamping parts

    1. Since the high-speed cutting lathe is controlled by a microcomputer program, a central processing unit is required to process a large amount of data quickly. It has high-capacity storage structure, high-speed data transmission and network transmission capability, error compensation, measurement error compensation function, symbol error compensation, thermal error compensation.

    2. The transmission system requires large feed speed and acceleration, generally 20-30 meters per minute and 20-40 meters per second.

    3. The main road of the airport. Because in the process of high-speed cutting, the mold needs to be milled at a very high speed, and the speed of the spindle must be synchronized with it. Generally speaking, it needs to be adjusted between 10,000-100,000 per minute, with fast acceleration and accurate shutdown. Therefore, hydrostatic pressure, air static pressure, suspended magnetic levitation, etc. Generally used for the arrangement of lathe bearings.

    4. The machining of automobile stamping dies is carried out with milling cutters, and the hardness and wear resistance of the tools are tested by thousands of turning millings. Therefore, the tool material must choose cemented carbide, polycrystalline diamond, etc. At the same time, the positioning of the tool must be accurate, and the error should be controlled within 0.001mm.

    There are many factors affecting the quality of automobile stamping parts, and the influence of die layout on stamping die is often small. The influence of the die radius, die event geometry, die guide method, drawing rib (slot) setting, die pore size and other factors on the forming effect of the drawn part.

    2. Determination of punch and die fillet radius

    The radius of the convex and concave die is an important factor in obtaining an ideal deep-drawn part. Wrinkling and tearing are the two main defects of covered tensile parts. If the punching radius is too small: the bending deformation of the straight wall and the bottom of the billet increases, and the strength of the dangerous section is weakened.

    When the radius of the die is too large, the tensile stress of the side wall of the blank increases accordingly. Both will increase the tensile coefficient and deformation resistance of the sheet, resulting in an increase in the total pull-out force and a shortened die life.

    If the punching or die radius is too large, the deformation force of the sheet is small, and the metal flow resistance is small, but it will reduce the effective area of ​​blanking and make the parts easy to wrinkle. Therefore, when determining the punch radius, the deformation characteristics of the workpiece and the drawing rib should be considered.

    3. The geometric figure part of the model

    The shape of each part of the die is different, which also affects the quality of the deep drawn part. There are two types: flat head dies and tapered dies. The use of tapered dies generally makes the deformed area of ​​the blank more resistant to instability, compared to flat-end dies (t/D). The smaller it is, the less wrinkled it is.

    Fourth, the mode-guided model.

    The wire drawing die consists of a punch, a blank holder, a blank holder and a blank holder. The rationality of the mold track is directly related to the reliability of the pull-out work. Reasonable and stable guide rails can ensure the uniformity of the gap around the mold and the coordination of the drawing surface, thereby ensuring the quality of the drawn parts.

    The above is the relevant content of automobile stamping die processing. The proportion of mold material and heat treatment is about 70%, which has become the main factor affecting the service life of the mold. Therefore, in the whole process of mold design and manufacture, it is very important to choose the correct mold material and heat treatment process. Hope the above will be helpful to readers.

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  • How to deal with the rust prevention of stamping and drawing parts?

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    Stamping and tensioning is a commonly used part in drawing and is widely used in many industries. Stamping and drawing parts should be treated with rust prevention during the production process to effectively avoid corrosion during use. Let’s take a look at the anti-corrosion treatment method of stamping and drawing parts. What is the effect of multiple stretches?

    1. Apply asphalt paint and preheat the stamping and drawing parts before spraying, which can improve the adhesion of asphalt paint and accelerate drying.

    2. Coating a special coating in the cement mortar can improve the corrosion resistance of the lining of the punching piece.

    3. Epoxy coal tar coating is a two-component coating with high adhesion and smooth surface.

    4. Epoxy porcelain lining is a kind of anti-corrosion coating for stamping parts. Due to the difficulty of production and high cost, the use has certain restrictions, and it has high adhesion and smoothness.

    5. Aluminate cement coating or salt cement coating, two kinds of special cement coatings are suitable for the anticorrosion of punching and pulling parts, and can improve the corrosion resistance.

    6. Polyurethane coating is a new type of green special coating with good wear resistance and corrosion resistance.

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  • What factors need to be considered in mold design in drawing mold processing?

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    The opening size also plays a non-negligible role in the production test of the entire mold. Therefore, in most cases, when designing irregular deep-drawn parts, a cavity is often left for deep-drawn part design.

    1. Stretch material.

    If the customer is not strict with the material requirements, and the repeated test model does not meet the requirements, you can replace the material with good tensile properties and try again. Good material is half the battle, and stretching cannot be ignored. The cold-rolled steel plate is mainly 08Al.08.08F.10.15.20 steel, and the amount used is 08 steel, which is divided into boiling steel and stable steel. The price of boiling steel is low and the surface quality is good, but the deviation is serious, and the phenomenon of strain aging is prone to occur. The foreign steel grade adopts Japanese SPCC-SD deep drawing steel, and its tensile properties are better than 08Al.

    Second, the surface processing of the drawing die.

    In deep drawing, especially stainless steel plate and aluminum plate are easy to produce drawing when deep drawing, and tensile fracture is serious.

    3. Determine the blank size.

    The more wrinkled the die, the less the crack is our principle. High positioning accuracy and high precision. Under the same stretching conditions, when the rotating body is pulled out, the thickness of the blank will change, but its thickness is basically the same as the original thickness. According to the same principle, the blank area and the drawn area (if needed to adjust, trim the allowance). But wire drawing is more complex in shape and process, and sometimes becomes thinner. Now, there is a lot of software for 3D that can extend the calculation of materials.

    Answer: Test data.

    A product needs to go through several processes, usually one process is blanking. Through the calculation of the unfolded material, the shape and size of the blank have been fully understood, and the overall size of the droplet mold has been determined. After the mold design is completed, the convexity and concavity of the mold cannot be processed. The blank is first machined by wire cutting. If the blank is relatively large, it can be milled with a milling cutter and then clamped), and then the size of the blank is determined by repeated tests of the subsequent wire drawing process, and then the die punch is processed.

    The above is the relevant content of mold design in drawing mold processing. Friendly advice. If the trial die is cracked, try applying lubricant (rapeseed oil, soapy water) to the lower die, or covering the die compound with a film wrap to get results. Proper antipyretic process can improve the plasticity of the material and reduce the multiple stretching of the parts. Hope the above will help readers.

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  • What are the influences of the design structure of the stamping die on safety?

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    Main components, functions and safety requirements of the mold. The convex and concave molds in the workshop generally refer to the working parts that directly shape the blank, because they are the key parts in the mold. The convex and concave die are not only precise and complex. It also needs to meet the following […]

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  • How to solve the springback problem of stamping parts?

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    1. Stress change curve after unloading

    (1) From ordinary plates to high-strength steel plates, stampings of different materials and strengths have different yield strengths. The higher the yield strength of the sheet, the easier it is to spring back. In the thick plate components, hot-rolled carbon steel sheets or hot-rolled low-alloy high-strength steel sheets are used as materials. The surface quality of the hot-rolled sheet is higher than that of the cold-rolled sheet, the thickness is small, the mechanical properties are unstable, and the elongation is low.

    2. Stress change before and after springback

    (2) In the forming process, the thickness of the material has an important influence on the bending performance of the plate. When the thickness of the plate increases, the springback phenomenon gradually decreases. With the increase of the plate thickness, the plastic deformation increases, the elastic recovery deformation increases, and the springback decreases.

    3. Tangential stress of board contacts

    With the continuous improvement of the quality level of thick plates, the problem of dimensional accuracy of parts caused by springback is becoming more and more serious. In order to understand the resilience properties and dimensions of the parts, take corresponding countermeasures and measures, carry out mold design and process debugging.

    The ratio of the bending radius to the thickness of the thick plate is small, and the stress change in the thickness direction cannot be missed.

    Parts of different shapes vary greatly in how they spring back on the part. Parts with complex shapes usually increase the number of moldings. They spring back when they are not formed in place, and some fractals are easier to spring back, such as U-shaped pieces, so bixu considers springback compensation when analyzing and forming.

    (4) The greater the bending angle, the greater the accumulation of rebound value, and the rebound will generate tension. The deformation length of the stamping part increases with the increase of the bending angle.

    (5) When designing the mold, the gap between the molds should not exceed twice the thickness of the material in the working part, and integrate the product into it. In order to obtain better material flow, the partial molding of the mold should be carried out after the mold is processed. Especially for bending dies, the larger the working gap, the larger the springback. When the thickness range of the sheet is small and the springback is large, it is difficult to determine the formwork gap well.

    (6) The bending radius is proportional to the amount of springback, so the greater the bending degree, the more difficult it is for the elbow to be bent.

    (7) The molding process is an urgency to limit the springback value. Generally speaking, the springback of positive bending is better than that of free bending. If the machining results of the same batch of stampings are the same, the bending force required to correct the bending is much greater than the bending force required for the free bending. Therefore, if both methods involve similar bending forces, the end result will be different. The greater the correcting force required to correct the bending, the smaller the springback of the stamped part, and the correcting moment will elongate the fibers in the deformed area to achieve the forming effect. When the elbow is unloaded, the surface and inner fibers are shortened, but the springback direction of the two sides is opposite, which reduces the outward springback of the stamping part to a certain extent.

    The above is how to solve the springback problem of automobile stamping parts. In short, the commonly used materials for automotive stamping parts must not only meet the technical standards of the designed products, but also meet the requirements of the processing technology such as drilling, electroplating, and cleaning after stamping. I hope it helps readers.

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  • What are the principles for the selection of stamping die materials

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    Stamping parts are common processed parts in daily life. They are widely used due to their excellent processing properties. The processing principle of stamping parts is to use stamping equipment and stamping dies to process materials, so stamping dies are generally specialized. Sometimes, a complex part requires several sets of molds to be processed and formed, and the molds are manufactured with high precision and high technical requirements. It is a technology-intensive product. In addition, if the quality of the stamping die is not good, problems are likely to occur during the processing, so the selection of stamping die materials also has certain requirements.

    First, the selection principle of stamping die material

    1. Production batch, when mass production of stamping parts, the die punch and die material should be selected from high-quality, wear-resistant die steel. Other process structural components and mold auxiliary structural components also need improvement. When the batch is small, the performance requirements of the material can reduce the cost.

    2. The performance of the material to be stamped. The conditions of use of the die. When the material to be stamped is hard or the deformation resistance is large, the convex and concave die of the die should be made of materials with good wear resistance and high strength. The aluminum bronze die has better adhesion resistance, so brushed stainless steel can be used. However, the guide column sleeve requires wear resistance and good toughness, so mild steel is mostly carburized and hardened. The main disadvantage of carbon tool steel is poor hardenability. When the section size of the stamping part is large, the center hardness after quenching is still low. . For fixing plate and stripping plate, it not only has sufficient strength, but also requires less deformation during the working process. In addition, the performance of parts can also be improved by cold and cryogenic treatment, by vacuum treatment and surface strengthening. For the cold extrusion die with harsh working environment of the convex and concave die, a die steel with sufficient hardness, strength, toughness, wear resistance and other comprehensive mechanical properties is selected, and it also has a certain red hardness and thermal fatigue strength.

    3. Material properties, considering the cold and heat treatment properties of the material and the status of the factory.

    In addition, it is common for blanking dies to burst during use, but in severe cases it is common for a die to be divided into several parts at a time. Of course, there are many reasons for the direct cracking of the template, and the procurement of materials from the mold design to the stamping process can all have an effect.

    2. The main reasons for die bursting are as follows:

    1. Unsmooth blanking.

    In production, there is no demagnetization treatment and no demagnetization phenomenon; in production, there are broken needles, springs and other materials; when assembling the mold, there is no leakage, rolling and blocking, which is a common phenomenon. If you do not pay attention during the assembly process, if there are too many blanking holes or mold jams, air leakage, rolling blockage and foot blockage are prone to occur during the assembly process. This is a common phenomenon. It can easily happen if you are not careful during assembly, if there are too many blanking holes or if the mold has spacers.

    2. Design process.

    The strength of the die is not enough, the distance between the knife edges is too close, the structure of the die is unreasonable, the number of templates is insufficient, and there is no pad foot.

    3. Heat treatment: improper quenching and tempering process leads to deformation.

    The experimental results show that the heat treatment quality of the mold has a great influence on the performance and service life of the mold. Through the analysis and statistics of the causes of mold failure, it can be seen that mold failure accidents caused by improper heat treatment account for about 40%.

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  • How to solve the problem of necking and pulling of stamping parts when processing aluminum alloy stamping parts of automobiles

    By : Categories : Blog,Techniques Comment: Comments Off on How to solve the problem of necking and pulling of stamping parts when processing aluminum alloy stamping parts of automobiles

    Compared with steel parts, the forming process of aluminum parts is more prone to necking and cracking. There are two main reasons for this problem:

    First, the stamping formability of the aluminum alloy sheet with the same plastic hardening index n value is much lower than that of the cold-rolled steel sheet. The thickness of the aluminum itself is lower than the anisotropy index, the deep drawability is large, the elongation after partial fracture is low, the forming window is narrow, and the forming capacity is only 1/3 of that of the steel.

    Second, aluminum has the characteristics of timeliness. As the heat treatment time increases, the strength, hardness, plasticity and toughness of aluminum itself decrease. Generally speaking, it takes 6 months to produce aluminum coils after heat treatment. In the 6-month production window, the mechanical properties of different batches of aluminum before production vary greatly due to aging, and the difference between mold margin and material properties Poor matching, necking and splitting occur from time to time.

    1. The shrinkage treatment plan of the stamping plant is as follows

    1. Plate aging control

    Aluminum sheet has aging properties, the strength increases with time, the hardness increases, and the plasticity decreases. Before stamping production, due to the different conditions such as the manufacturing process of the plate, the factory state after heat treatment, transportation, and temperature, the mechanical properties of the aluminum plate material before stamping production are quite different, which has a great impact on the production adjustment of the mold, and also leads to frequent production in continuous production. There are problems such as necking and pulling cracks. In order to solve this problem, we can first accumulate the range of mechanical properties for stable production of the mold, and then use the aging characteristics of aluminum to master the timeliness law, and stop using the aluminum with a low yield, so that it is naturally aged, and the yield strength is increased to After the expected range can be produced.

    2. Early warning and intermittent supply of aluminum plate mechanical properties.

    Renovate the board material card, and print all the board information on the material card, which is convenient for problems in the production process, and can quickly compare and analyze the performance of the material. In addition, the index data of performance problems in production is also summarized and summarized, and the performance early warning range of each aluminum alloy stamping part is formed, and the blue card material is used beyond the time range, which plays a role in early warning of defects.

    3. Use digital methods such as Autoform and ATos to help optimize the pulling and cracking of the neck region.

    The die set position is prone to necking, especially when the theoretical necking maximum point reported in the drawing simulation or exceeds the safety margin line (FLC), which can be optimized in digital software and equipment.

    4. Intelligent grid monitoring system.

    According to the experience, the position where the aluminum parts are prone to necking and fracture is summarized, and the mold margin monitoring is carried out on these parts. The main application is the grid strain analysis device (4×5 million pixel three-dimensional stereo camera), the hand-held camera shoots, and the specific situation of the grid strain in the monitoring area can be obtained. It takes about 1 hour from the shooting to the end of the computer operation. The advantage is that it is easy to operate , Fast and easy to calibrate. After the analysis report is output, it will prompt which location is safe and which location is risky. For risk points, mold maintenance personnel evaluate further optimization.

    5. Develop equipment with special functions.

    In the current stamping parts production equipment, the drawing lower air cushion can realize the function of segmental pressure. The cover plate is set with a small pressure in the early stage of forming, and then the air cushion pressure is set under the segment. The segmental pressure setting can effectively solve the cracking problem of deep-drawn aluminum alloy stampings.

    The above is the relevant content of automobile aluminum alloy stamping parts processing. Any machining parts need different machining plans according to their materials and characteristics, and solve problems in a timely manner during the machining process. I hope the above will be helpful to readers.

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  • By : Categories : Blog,Industry,Techniques Comment: Comments Off on

    In the processing industry, molds are indispensable equipment, and different processing industries choose different molds. Metal stamping dies and plastic processing dies are widely used in industrial production. As for the difference between them, many people will say that metal stamping dies are made of metal, and plastic processing dies are made of plastic. What is the essential difference between metal mold and plastic mold? What are their main areas of application? To understand the difference between the two, we must first understand what is a metal stamping die and what is a plastic die.

    1. The difference between metal mold and plastic mold

    1. Metal molds refer to stamping parts processed by using various presses and special tools in industrial production to process metal materials according to the shape required by the finished product. This special tool is often called a metal mold.

    2. Plastic mold is a combination of plastic molds, which can be used for compression molding, extrusion molding, injection molding, blow molding and low plastic, and can be used as mold punch, die and auxiliary molding system. A range of plastic products that can be processed in various shapes and sizes.

    3. From the perspective of the role of the mold, the metal mold is a mass production tool for metal products. The materials used are generally iron or copper or aluminum, the plastic molds are plastic products, and the raw materials used are also plastic raw materials.

    4. The most fundamental difference between metal molds and plastic molds is the structure of the molds. Plastic molds have cooling systems, but metal molds do not. The molding principle of the product is also different. The plastic mold is cooled and formed after injection molding, and the metal mold is punched into a standard thickness steel plate.

    5. Hardware molds and plastic molds are made of steel. Stamping metal molds generally use cold steel. If it is a pressure injection mold, hot-working steel is required. The plastic mold is generally hot-working steel. The mold is more complicated. Mold) There is no gating system and cooling system, which can be understood as: plastic mold processing is to cool plastic flow into the cavity in a closed space for cooling and forming.

    Second, the metal stamping die has the following advantages

    Due to the use of mold processing, metal stamping parts that cannot or are difficult to manufacture by other processing methods, are thin-walled, lightweight, have good rigidity, good surface quality and complex shapes can be obtained. The dimensional accuracy of the blanked parts is guaranteed by the mold, and the characteristics are exactly the same, so the general press can produce dozens of parts per minute, while the high-speed press can produce hundreds of parts per minute. Therefore, it is an efficient processing method.

    3. Plastic processing molds have the following advantages

    Plastic molds have high tolerances, low repetitive labor costs, and can use a variety of materials. The waste loss is far less than that of metal molds, and there is no need to continue to improve parts after plastic molds are formed.

    The above is the relevant content of metal stamping dies and plastic dies. These two molds are suitable for different industries and different processing requirements, so the production methods of the molds will also be different. I hope the above will be helpful to readers.

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