With the development of science and technology in recent years, the technical application of the mold industry is also constantly improving. Die companies have been working hard to improve the quality of die steel metallurgy research. After years of hard work and exploration, at present, the main metallurgical production departments at home and abroad are committed to the improvement of metallurgy quality of mold steel, mainly in the following aspects: 1. Smelting quality For high-quality mold steels, the use of external refining, vacuum processing, vacuum smelting, powder spraying, electroslag remelting and other processes are widely used at home and abroad to reduce the content of harmful elements, oxygen, hydrogen, and inclusions in steel, and to carry out chemistry. Fine adjustment of composition and pouring temperature. Through electroslag remelting, it is also possible to effectively improve the low-order microstructure and denseness of the steel, and to improve the isotropic properties of the mold steel. Tests by some domestic manufacturers show that the transverse impact toughness value of 4Cr5MoSiV1 steel manufactured by electric arc furnace is only equivalent to 31% of the longitudinal direction. After 4Cr5MoSiV1 steel after electroslag remelting, the transverse impact toughness value can be equivalent to 70% of the longitudinal strength. , increase more than 1 times. For special requirements of the mold steel, the powder high-speed steel and powder high-alloy mold steel produced by the powder metallurgy process are used to better improve the microstructure and properties of the steel. 2. Forging rolling process On the basis of guaranteeing a certain forging ratio, the long forging and cross-rolling processes are applied as far as possible to increase the isotropy of the mold material. In order to reduce the machining allowance and increase the utilization of materials, the precision forging machine, quick forging hydraulic press and high-precision continuous rolling mill are widely used to produce high-precision steel and meet the needs of mold manufacturing. 3. Heat treatment and finishing For heat treatment of forgings and rolling stocks, controlled atmosphere or vacuum heat treatment should be adopted to avoid oxidative decarburization; for some plastic die steels and hot die steels, the metallurgical department should perform pre-hardening treatment; for some high-demanding hot work die materials The metallurgical department should organize and refine the steel in advance to eliminate coarse carbides and chain-like distribution carbides in the steel, and obtain fine and evenly distributed carbide structures to further improve various properties of the steel, especially to equalize. Sex. According to reports from some foreign countries, some hot die steels have undergone electroslag remelting—multi-directional forging (rolling)—microstructural refinement to produce high-quality, high-tropism die steels with comparable transverse impact toughness values. Over 90% in the vertical. Many steel mills have named the steels produced by this process, such as the ISODISC of the Austrian Bole Steel Works; the ISOTROPY of Hitachi Metals of Japan; the Microflex of Japan's High Frequency Steel Co., etc. Many metallurgical production departments in China are also devoting themselves to this work. In addition, considering the metallurgical quality of various parts of the steel, during the production of the mold, attention should be paid to making the main working surface of the mold (such as the cavity or blade) select the position of the surface of the steel; because in general, the surface of the steel is a comparison of steel. The clean part, and the steel core is the area where the low-defects are more concentrated; especially in the large section of the refinery steel, the eutectic carbide unevenness of the central part of the steel is 2-3 times higher than the surface part. level. In addition, the direction of the main load bearing the mold can best be selected in line with the deformation direction of the steel, in order to reduce the anisotropy of the steel on the adverse effects of the mold. 4. Thermal conductivity The thermal conductivity is also one of the main performance indicators of the mold steel, especially some hot work mold steel and plastic mold steel. Good thermal conductivity mold steel can quickly transfer the heat generated during processing and the heat transferred from the workpiece to avoid overheating of the mold working surface and improve the working conditions of the mold. For some molds for thermoplastic molding and some die-casting molds, in order to speed up the production rhythm, it is hoped that the pressed parts will be quickly cooled and demolded to increase productivity. In order to solve this problem, mold materials with better thermal conductivity than steel are sometimes used, such as High-strength copper alloys, high-strength aluminum alloys, etc. 5. Concentrate and product In order to shorten the manufacturing cycle of the molds, the mold manufacturing department should use fine materials and products as far as possible when selecting the mold steels. For example, fine steel products that have been stripped, cold-drawn, or ground are roughed, finished, and even refined. Process quenched and tempered modules. The mold manufacturing department uses these fine materials and products to be slightly processed and can be assembled with a standard mold base. It can not only effectively shorten the cycle of mold manufacturing and meet the needs of the mold use department, but also because the production of concentrates and products in the previous phase is a high-efficiency mass production in the metallurgical plant, which can reduce production costs and increase material utilization. 6 other factors that should be considered in the reasonable choice of mold steel In the choice of mold steel, according to the use of mold conditions and requirements, in addition to the above factors must be considered, especially the main properties of the mold steel must meet the requirements of the use of the mold, but also need to consider the price of the selected mold steel And versatility. Under normal circumstances, when the production of a large number of workpieces, the size of the mold is small, the proportion of mold steel in the mold manufacturing cost is very small, the price of mold steel may not be taken as the main considerations, you can try to choose more advanced Mold steel. For molds with large or extra-large shapes that are relatively simple, the cost of the mold steel will account for a large share of the total cost of the mold. Therefore, depending on the volume of the production workpiece, the mold steel with a lower price may be used or the mold body may be selected. Low-cost mold steel, but in the key working parts of the mold, such as the cavity or cutting edge, using insert or surfacing methods to insert high-grade mold steel or surfacing up, not only can improve the life of the mold, It can also reduce material costs. The versatility of the mold steel is also a factor that must be considered when selecting the mold steel. The mold steel is generally not used in large quantities, and there are many varieties and specifications. In order to facilitate procurement and stock preparation in the market, the versatility of materials should be considered. In addition to special requirements, mass production of universal mold steels is used whenever possible. As the general-purpose mold steel technology is relatively mature, the accumulation of production process and use experience is more, the performance data is relatively complete, easy to refer to in the design and manufacturing process; In addition, the use of general-purpose mold steel, but also easy to purchase, material preparation and material management jobs. Atlantic Salmon Extract,Salmon Sperm Dna, Anti-aging Raw Material Pdrn Ruijiming (Shandong) Biotechnology Co., Ltd , https://www.mgpdrn.com