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Die steel-the base of mold manufacturing

    As China’s economy continues to grow rapidly, the domestic mold manufacturing industry is developing rapidly at a growth rate higher than GDP. This has also provided a huge market for the development of domestic die steel, and has driven the rapid improvement of domestic die steel production, varieties, specifications and quality levels. As the base of mold manufacturing, the performance of mold steel directly affects a series of factors such as the service life and production cost of the mold, and is being valued by more and more mold manufacturers.
    Research and development of new cold work die steel
    Mr. Kenichi Adachi: The automobile industry has always been regarded as the driving force behind the industries of various countries. At present, various automobile manufacturers are rapidly expanding the effective use of high-strength steel plates (super-hard, super-strong) in order to achieve lightweight and safe design. However, from the difficulty of forming in the stamping process itself, the problem of die life has been increasingly put on the agenda.
    On the other hand, the cost reduction and short delivery period faced by the mold industry are already imminent. Therefore, both industries are most eager to develop mold materials that are easy to cut and have less dimensional deformation after heat treatment. Hitachi Metals combined the experience and development capabilities accumulated over 100 years of steelmaking to develop the next generation of cold work die steel that far exceeds the characteristics of commonly used materials SKD11, that is, SLD-MAGIC.
    Through the comparison test with SKD11 modified steel 8%Cr steel (our company’s product SLD8), the high-performance new cold work die steel SLD-MAGIC has shown considerable performance in terms of improving die life, reducing the total cost of die production and shortening the delivery period. Advantage. Mainly reflected in the following aspects:
    -Abrasion resistance: the highest hardness is HRC62, its abrasion resistance is increased by about 35%, which greatly improves the life of the mold.
    -Surface treatment: The adhesion of the surface treatment film (CVD and other methods) is increased by about 30% to prevent the bending and stretching of high-strength steel from scratches during forming.
    -Heat treatment characteristics: The size of heat treatment is reduced by about 40%, and the deviation of the shape will be improved. For heat treatment and surface treatment, the dimensional deformation is small, and the repair time is reduced.
    -Machinability: Machinability is improved by approximately 35%, and the machining time is shortened in mold manufacturing based on the improvement of machining efficiency.
    The above properties of wear resistance, heat treatment properties, surface treatment properties, and machinability are representative data compared with our company’s material SLD8, and may differ slightly from the actual product properties.
    The rapid development of the mold industry puts forward new requirements for mold steel
    Dr. Li Shi: Generally speaking, in addition to drawings, technical standards also include the selection of mold materials, specific heat treatment processes, control of electrical discharge machining, surface roughness, and surface treatment of mold parts (such as die-casting pins). This requires mold steel suppliers to provide high-performance mold steels for different application requirements, and to communicate with mold manufacturers about process requirements specified by mold manufacturing specifications other than material properties, such as surface coating processes. Ober-Dewar Mould Technology (Wuxi) Co., Ltd. can provide a large number of mold manufacturers with high-quality mold steel produced by French Ober-Dewar, and the existing sales team can communicate with those mold manufacturers to reach foreign buyers Specified technical specifications. The company provides hot work mold steel, cold work, plastic and glass mold steel. In some applications, such as high-pressure die-casting molds, the French Ober-Dewar has its own internal production technical specifications. The products produced are designated and approved by European and American automakers. Its product quality is higher than European and American industry technical specifications (such as NADCA North American Die Casting Society specifications) and ensures the stability and long-term life of the mold. In this application, Ober-Dewar’s ADC3 is especially suitable for those large mold applications. One of the current development trends of the automobile industry is to use pressure casting to manufacture large aluminum and magnesium alloy parts, such as automobile engine blocks. The manufacture of such products requires the thickness of die steel to be more than 300mm, and three-dimensional forged steel is the first choice. The Ober-Dewar plant is unique in three-dimensional forging, which ensures the uniformity of the three-dimensional performance of the materials used. In addition, Ober-Dewar’s SMV3W (1.2343ESR) and SMV4S (1.2344ESR) have also been designated by car manufacturers. In Europe, the above three types of products have shown good performance in practical applications and prolonged the life of the mold, thereby reducing the cost of a single part. In some applications, such as the production of automobile gearbox housings, the life of molds made of ADC3 steel has reached more than 200,000 pieces, which is much higher than the commonly used 1.2344ESR steel.
    In the application of plastic molds, the steel grade X15TN produced by Ober-Dewar adopts the manufacturing process of replacing carbon alloy elements with nitrogen to ensure the excellent polishing performance of this steel grade. X13T6W (S236), MEK4, SMV3W are used on reflective plastic parts of automobile lights, and have excellent polishing performance without the common polishing pinhole phenomenon. The impurity content of each steel grade is extremely low. The impurity sulfur (S) content of the product is within 5PPM, and the oxygen content is within 10PPM.
    With the rapid development of the mold manufacturing industry, mold suppliers must be able to provide high-quality, high-performance mold materials to meet the various requirements of customers. At the same time, the supplier must have a team of sales experts who can provide customers with system application recommendations. In this regard, Ober-Dewar can provide customers with excellent products and services to promote the improvement of the overall mold manufacturing standards.
    Research and development of new materials for die steel
    Mr. Yukiko Uemura: DRM was developed by Datong Special Steel in Japan in recent years. In order to realize high-speed steel with high hardness and high toughness, the coarse carbides are reduced to the limit, the service life is increased, and the mold cost is reduced.
    The reason why it is called matrix high-speed steel is because it is different from ordinary high-speed steel. After heat treatment, crystalline carbides (primary carbides) and precipitated carbides (secondary carbides) still exist and cannot be dissolved into the matrix. DRM matrix high-speed steel after heat treatment, crystalline carbides and precipitated carbides can be dissolved into the matrix to reduce coarse crystalline carbides, so as to better inhibit the occurrence of cracks and improve toughness. Large cracks, micro cracks (fatigue cracks) and wear will occur in the mold during use. In order to prevent the occurrence of such situations, the toughness, fatigue strength and hardness should be increased. This is also the base steel of DRM with high hardness and high toughness. The necessity and particularity of
    The DRM series is divided into DRM1, DRM2 and DRM3, which can be applied in multiple ranges.
    DRM1 is a matrix high-speed steel that achieves high hardness and high toughness that cannot be achieved by general hot work tool steels. Compared with the previous matrix high-speed steel, it has higher toughness and is suitable for various hot and warm forging molds. Mainly used in punches and dies for hot forging; punches and dies for warm forging. Its main features are: ①It can be used under the highest hardness of 58HRC. ②High hardness, high toughness, and good thermal crack resistance. ③It has the same level of fine structure as the hot die steel, and has higher toughness than the current base high-speed steel. ④High softening resistance and good high temperature strength. ⑤Because of special dissolution, there are few non-metallic inclusions and excellent homogeneity.
    DRM2 is a matrix high-speed steel that can be widely used under severe conditions such as warm and cold pressing tools. To achieve higher hardness and toughness than the previous matrix high-speed steel, suitable for various temperature, temperature forging, cold forging, powder metallurgy molds. Mainly used in warm forging punches and dies; cold forging punches and dies. Its main features are: ①It can be used under the highest hardness of 62HRC. ②Fine structure, high toughness value and good fatigue properties. ③The hardenability is good, and the hardening of large diameter materials and vacuum heat treatment can also maintain high performance. ④Due to special dissolution, there are few non-metallic inclusions and excellent homogeneity.
    DRM3 is improved on the basis of the previous MH85. Its high hardness and high toughness are suitable for high-speed steel corresponding to vacuum hardening for high-precision product forming. Suitable for all kinds of cold room molds. Mainly used in cold forging punches and dies; cold working rolls and engraving rolls; high-speed tool steels and tools for vacuum quenching. Its main features are: ①It can be used under the highest hardness of 66HRC. ②The carbide is fine, with higher toughness and higher fatigue strength than SKH51. ③Good hardenability, high performance can also be maintained for large diameter materials and quenching in a vacuum heat treatment furnace. ④Due to special dissolution, there are few non-metallic inclusions and excellent homogeneity.