What is the reason for the failure of stamping and drawing dies in processing and casting?

1. The process of stamping and drawing die

Punching die is a method of casting liquid die forging, a process completed on a special die-casting die forging machine. The basic process is: the molten metal is first cast into the mold cavity at a low speed or high speed, and the mold has a movable cavity surface. With the cooling process of the metal liquid, pressure forging not only eliminates the shrinkage defect of the blank, but also makes the internal structure of the blank reach forging. Broken grains.

2. The main reasons for the failure of stamping and drawing dies are as follows:

1. Thermal fatigue crack damage failure

During die-casting production, the mold is repeatedly subjected to the action of cold and heat, the forming surface and its interior will be deformed, and they will be pulled together to generate repeated thermal stress, which will cause damage to the structure and loss of toughness, which will lead to the occurrence of micro-cracks and continue to expand. , once the crack expands, the molten metal is continuously squeezed in, coupled with repeated mechanical stress, the crack accelerates the expansion rate. Therefore, the mold must be fully preheated at the beginning of die casting. In addition, during the production process of die casting, the mold must be kept in a moderate working temperature range to prevent early cracking failure. At the same time, it should be ensured that there are no problems with internal factors before the mold is put into production and during production. Because in actual production, most mold failures are failures caused by thermal fatigue cracks.

2. Fragmentation failure

Under the action of pressure, the mold will crack at the weak place, especially if the scribe marks or electrical machining marks on the molding surface of the mold are not polished, or the clear corners of the molding will appear micro cracks first. When there is a brittle phase or coarse grains in the boundary, it is easy to fracture. However, the cracks expand rapidly during brittle fracture, which is a very dangerous factor for the chipping failure of the mold. For this reason, on the one hand, all scratches and electrical machining marks on the mold surface must be polished, even if it is in the gating system part, it must be polished. In addition, the mold materials used are required to have high strength, good plasticity, good impact toughness and fracture toughness.  

3. Dissolution failure

Commonly used die-casting alloys include zinc alloy, aluminum alloy, magnesium alloy and copper alloy, as well as pure aluminum die-casting. Zn, Al, and Mg are more active metal elements, and they have a good affinity with mold materials. When the hardness of the mold is higher, the corrosion resistance is better, and if there are soft spots on the molding surface, the corrosion resistance is unfavorable.  

Do you know what are the common mold processing methods?

1. Can use CAD mold processing method

When processing molds, a common method is the mold CAD method. When processing molds, this method generally adopts some ready-made mold standards to directly process molds. Because there are many products in design, the appearance is very similar, so in processing When making molds, for these products with small differences in appearance, some existing mold standards can be directly selected for processing and manufacturing, so that the molds can be manufactured faster. This manufacturing method is suitable for many mold processing and manufacturing, and some integrated technologies can be used when manufacturing molds.

Second, you can choose the die CAD mold processing method

When manufacturing molds by this method, it is somewhat similar to the first method, but it is improved on the basis of the previous method. When using this method to process and manufacture molds, some blanks are used, and the blanks are further optimized, so that the utilization rate of the manufactured molds is higher. When using this method to manufacture molds, due to the different requirements of each part, the methods used are also different in the stamping process. Using this method can greatly improve the utilization rate of blank materials.

3. You can choose the mold processing method of computer layout

With the continuous development of science and technology, computers play an increasingly important role in people’s lives. When people process and make molds, they can use the computer to lay out the layout and lay out several different styles through the computer. When using a computer for nesting, people can use two different nesting methods: semi-automatic and fully automatic. These two different nesting methods use different algorithms and characteristics. The entire production process can be completed more efficiently during processing.

Fourth, the stamping die processing method can be used

When manufacturing the mold, people can also use some mathematical models to describe the mold, and then use the stamping process to process and manufacture the mold. When this method is used, the precision of the manufactured mold can be higher. , the structure of each part is more perfect, and the strength of the mold can be relatively strong. By stamping the mold in an all-round way, the manufactured mold can more meet the needs of people.

There are many different mold processing methods, and people can choose different methods according to their needs for molds.

What should be paid attention to in the production of precision stamping parts

With the improvement of science and technology, people have higher and higher requirements for the precision of products. The stamping industry is no exception. While the demand of customers for precision stamping parts is growing, the precision requirements for products are also increasing. In the production process, the production of precision stamping parts should not only consider the shape and size of the product, but also consider the impact of stamping dies, punches and other matters. In order to ensure the production of qualified precision stamping parts, Balford Precision has summarized the following points needing attention after years of production experience and shared them with everyone:

1. It is necessary to regularly check the performance of the punch and the parallelism and perpendicularity of the workbench.
2. The production of precision stamping die shall be strictly controlled. If the stamping factory does not have the ability to independently develop the mold, it needs the support of a stronger mold supplier. The quality of precision stamping die determines the quality of precision stamping parts. Therefore, we need to ensure that there are no mistakes in the mold, otherwise the consequences will be unimaginable.
3. Before installing the mold, be sure to strictly check whether the mold and the press are clean, and check the lubrication of the mold guide post.
4. During the production process, the springs should be checked and replaced regularly to avoid problems with the springs and affecting the quality of precision stamping parts.
5. The stamping factory needs to formulate work standards to ensure that the stamping workers operate according to the standards when installing the stamping die.
6. In the actual production process, if the die edge is worn, it needs to be repaired or replaced in time, otherwise the die will be more damaged.

In addition to the same preventive measures as conventional stamping parts, the main purpose of ensuring the product quality of precision stamping parts is to pay attention to the maintenance and care of the punch and stamping die. Only under the condition of ensuring the accuracy of the punch and die can the stamping factory produce qualified precision stamping parts.

Stamping

Stamping (also known as pressing) is the process of placing flat sheet metal in either blank or coil form into a stamping press where a tool and die surface forms the metal into a net shape. Stamping includes a variety of sheet-metal forming manufacturing processes, such as punching using a machine press or stamping press, blanking, embossing, bending, flanging, and coining. This could be a single stage operation where every stroke of the press produces the desired form on the sheet metal part, or could occur through a series of stages. The process is usually carried out on sheet metal, but can also be used on other materials, such as polystyrene. Progressive dies are commonly fed from a coil of steel, coil reel for unwinding of coil to a straightener to level the coil and then into a feeder which advances the material into the press and die at a predetermined feed length. Depending on part complexity, the number of stations in the die can be determined.

Considerations for Deep Drawn Stamping

When considering deep drawing to meet your manufacturing needs, you should pay attention to the following points:

Reduce material waste: compared to other metal forming processes, deep drawing uses more base materials, significantly reducing material waste.

Measurement is critical: it is not only important to ensure accurate mold dimensions, but also important to consider material thickness and required measurement values. Incorrect measurement will lead to thin walls and inaccurate dimensions.

Draft and Taper: Due to the basic manufacturing process of deep drawing, some drafts and tapers at the top of the part are unavoidable. This should be considered at the initial design stage.

Different material thicknesses: Deep drawing parts usually have different thicknesses, with thinner walls and thicker bases. This can be mitigated by tools after the wire drawing process is completed.

stainless steel Enclosures

Minimize guide and weld issues with deep drawn metallic enclosures. When engineering depends with a situation to perform reliably, even within the most demanding environments, it is really the perfect time to

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

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.

Why do precision metal molds have substandard products?

1. Reasons for unqualified products of metal stamping parts

1. The product is unqualified due to the springback of the material. At this time, we can reduce the springback of the stamping parts through the following methods, use the stamping material with stable mechanical properties, increase the annealing process, and use the correction bending. The material should be de-fired before bending, and the cooled material should be softened before bending; if it is difficult to eliminate the deformation during the stamping process, the slope of the model should be adjusted at this time.

2. If there is a problem with the positioning of the strip due to the deformation and wear of the positioner, a new positioner must be replaced.

3. When adjusting the press, if the low position of the slider is not adjusted well, the bending parts are not qualified.

4. The pressing equipment of the mold does not have the function of pressing the material. It must be repaired or replaced with a new pressing spring or the pressing force must be adjusted.

5. After a long time of use, some parts of the mold are loose, which causes the position of the abrasive tool to change.

6. It may also be caused by the operator not using the mold as required.

The above is why there are unqualified metal stamping parts. I hope the above content can help readers.

Electronic Stampings Parts

The surface and intrinsic properties of electronic stamping materials have a great influence on the quality of stamped products. The thickness of stamping material is required to be precise and uniform; the surface is smooth, no spots, no flaws, no scratches, no surface cracks, etc.; Uniform yield strength, no obvious directionality; high uniform elongation; low yield ratio; low work hardening.

Deep drawing engineering drawing

Design for deep drawing Sheet metal stamping deep drawing metal stamping manufacturing technology is defined as the stretching of sheet metal stock, commonly referred to as a blank, around a plug. ...

Drawing parts processing standards and process precautions

1. Processing standard of drawing parts

Stretching parts are workpieces obtained by stretching and deforming the sheet by mechanical equipment. Now Xiaobian will introduce the production standards of our stretching parts for you.

1. The first-wall surface, bottom surface and wall surface of the deep-drawing part, and the corner radius of the four corners of the rectangular part should be appropriate. mm2rd1, mm5.1r2d.

2. The shape of the stretched part should be simple and symmetrical, and it should be stretched at one time as much as possible.

3. For parts that need to be stretched many times, on the premise of ensuring the required surface quality, traces that may be produced on the inner and outer surfaces should be allowed.

4. On the premise of ensuring the assembly requirements, the side wall of the deep drawing part should be allowed to have a certain slope.

5. The dimensions of the deep-drawn parts should be marked with their outer or inner dimensions, and the inner and outer dimensions should not be marked at the same time. With trapezoidal deep-drawing parts, the dimension in the height direction should generally be based on the bottom. If the upper part is the benchmark, the height dimension is not easy to guarantee.

6. The distance from the hole on the bottom or flange of the deep drawing piece to the side wall should be appropriate.

2. Precautions when using tensile parts

As we all know, tensile parts are prone to residual stress during machining, and there is a high residual stress near the yield limit. Most residual stresses have significant adverse effects on components, such as reducing their actual strength, fatigue limit, stress corrosion and brittle fracture. Due to the relaxation of residual stress, the parts are warped, which greatly affects the dimensional accuracy of the parts. So, what should we pay attention to when working with extruded parts? Let our stretched parts manufacturers explain it to you.

1. Regularly check the turntable and die mounting seat of the punch press to ensure the coaxial accuracy of the upper and lower turntables.

2. Before using stretch metal stamping parts, it is necessary to strictly inspect, clean up dirt, and carefully check that the guide sleeve and mold of stretch stamping parts are well lubricated.

3. In order to ensure the service life of the drawing and punching parts, the die spring should be replaced regularly to prevent the spring from fatigue damage and affect the use of the drawing and punching parts.

4. When installing the mold, the puncher should use softer metals (such as copper, aluminum, etc.) to make operating tools to prevent damage to the drawing punch during the installation process.

5. When the punch and die edge of the pulling and pressing part are worn, they should be stopped immediately and ground in time, otherwise the wear degree of the die edge will be rapidly expanded, the die wear will be accelerated, and the quality of the stamping parts and the life of the die will be reduced.

6. According to the installation procedure of the mold, install the convex and concave mold on the turntable to ensure that the direction of the convex and concave stretched stamping parts is consistent, especially the direction requirements (non-circular and square), to prevent installation errors and reverse installation.

3. Precautions and uses for the processing process of drawing parts

Have you ever wanted to ask how much you know about the accessory product of tensile parts? I am afraid that few people know what this accessory is used for and how it is processed. This kind of drawing part is a shaped slab or hollow part drawn to make various open stamping parts. This kind of workpiece often appears in our daily life, but we have not really understood the purpose and function of the product. Next, we will introduce you to the production process considerations and performance aspects of stretched parts.

Due to the special production process of wire drawing, this production method can be made into thin-walled parts with complex shapes such as cylinder, box and spherical. Rally has its unique production method in tractors, electrical appliances, electronics and other industrial and daily necessities, so it has a considerable position. If the drawing parts are used as installation and processing items, if there is any missing or missing, it will cause the valve to lose control and damage the piston and other workpieces, and if it is used in the case of missing installation, it will cause serious failure, which is also a detail to pay attention to. question.

Unturned tire casings stacked for a long time will be deformed by squeezing. If a squeeze condition occurs, the filtering effect is not reliable. Therefore, we need to pay attention to all aspects of our workflow and daily routines so that the stretched products we produce are fully functional.

The above is the processing standard and process description of drawing parts. Everyone should know about it. Therefore, the manufacturer of tensile parts reminds you that only the correct treatment of tensile products can play an important role in its performance. In addition, the service life is also highly ductile. I hope the above will be helpful to readers.

What problems should be paid attention to in the production process of metal stamping parts?

1. Precautions for the figure of metal stamping parts

1. Wrinkles on the side walls of the parts: The main reasons for the wrinkles on the side walls of the parts are insufficient material thickness (thinner than the minimum allowable thickness) or eccentricity when installing the upper and lower molds, resulting in a large gap on one side and a small gap on the other side. Precautions are to replace the material immediately and readjust the mold.

2. Scratches on stamping parts: The main reason for scratches on parts is that there are sharp scars on the mold or metal dust falls into the mold. The preventive measures are to grind the scars on the mold and clean the metal dust.

How to solve the stamping problem of electric vehicle stamping parts

The die set can be dismantled in time to check the abnormal cause of imprinting. It is verified from the consistency of the lower plane of the ejector pin and the die, and the rigidity of the lower backing plate and the lower bottom plate. It is found that the cause of the imprinting on the surface of the part is the concave The height of the mold and the push block is inconsistent. The source is that the backing plate has no hardness, and it sags after mass production, resulting in imprinting problems.

The imprint on the stamping part is caused by the protruding part of the part of the stamping die that should not be raised, and the raised part should be ground or replaced.

First of all, find the cause and location of the imprinting, and then blow the iron filings away with the blowing nozzle in the place where iron filings are likely to be generated, and check whether the mold blade is unhappy and causes too much iron filings. In addition, check it frequently during operation. , to see if there is an embossing.

The main reason for this anomaly is that the die set did not heat the die pad, and it was handed over to the responsible department for rectification. After rectification, the bottom-cutting problem solved the root cause of the imprinting problem.

What are the five use skills of laser cutting technology?

1. Five skills of sheet metal processing

1. The dual-focus laser cutting head is a wearing part on the laser cutting machine, which will be damaged after long-term use.

2. Check the straightness of the laser cutting machine track and the verticality of the machine every six months. If any abnormality is found, repair and debug it in time. Vacuum the dust and dirt from the machine once a week. All electrical cabinets should be tightly closed to prevent dust.

3. Always check the steel belt of the laser cutting machine to make sure it is tight. Otherwise, someone could be injured or even killed if the operation goes wrong. The steel belt may seem like a trivial matter, but if there is a problem, it is still a bit serious.

4. One thing that needs to be reminded in sheet metal processing is that each guide rail of the laser cutting machine should be cleaned regularly to eliminate dust and other debris, and the frame should be regularly wiped and lubricated to ensure that the lubrication is free of debris.

5. The guide rail should be cleaned and lubricated frequently, and the motor should also be cleaned and lubricated frequently, so that the machine moves better during the traveling process, the cutting is more accurate, and the quality of the cut products will also be improved.

Key Points for Use of Continuous Stamping Die

The manufacturers of precision stamping parts choose to use the continuous stamping die when stamping, which has the advantages of high mass production efficiency, easy to realize automation, and low cost. At the same time, we should not forget the key points of using the continuous stamping die to avoid affecting the quality of stamping products and the service life of the stamping die.1. The metal stamping parts need to be suitable for continuous die stamping. First, the batch size should be large enough, the feeding accuracy and the cumulative error between each work step should be designed reasonably, and the accuracy of the parts should not be reduced. The parts with complex shape and difficult to locate after punching are usually stamped with continuous die, which is ideal for z;

2. The press used for the continuous die should have sufficient strength, stiffness, accuracy and other factors, and the stroke should not be too large to ensure that the guidance system does not disengage during operation, generally working at less than 80% of the nominal pressure;

4. Stamping materials should have good mechanical properties. Each batch of incoming materials should be inspected and tested according to the regulations. Only when the materials are straight can they be put into production. The quality of materials directly affects the production of metal stamping parts;

3. Key points of design, manufacture and maintenance of continuous die for metal stamping parts. Due to the complex structure of the continuous die, its manufacturing accuracy is higher than that of general dies. After each batch of production, inspection and maintenance are required. Only qualified parts can be put into the die warehouse. Some small accessories and inserts need to be replaced in time after wear; If the mold has been ground, the corresponding other parts should also be ground equally to ensure the same height, which is required to be consistent with the relative difference of the original design. Therefore, the level of the mold workers and special equipment should also be equipped.