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CN-121992307-A - Improved die steel with high mirror polishing characteristic and preparation method thereof

CN121992307ACN 121992307 ACN121992307 ACN 121992307ACN-121992307-A

Abstract

The application relates to improved die steel with high mirror polishing characteristics and a preparation method thereof. The material comprises the following raw materials in percentage by mass: c: 0.30-0.42%; si: 0.71-1.20%; mn: 0.12-0.53%; cr: 4.50-5.50%; mo: 2.01-3.02%; v: 0.30-0.61%; p: less than or equal to 0.012%; s: less than or equal to 0.002%; synergistic element: 0.01-0.10%: the balance of Fe and other unavoidable impurities; the synergistic elements include: f0.008 0.012%, rare earth 0.03 0.035%, nb0.03.04%, B0.002.003%, this application forms synergistic system through adding synergistic element (F, rare earth, nb, B four), has high mirror polishing characteristic, anti-fouling performance, durability etc..

Inventors

  • SUN JIANGUO
  • FU HAO
  • ZHU YUNHUI
  • ZHANG XUDONG

Assignees

  • 江油市重鑫特种金属材料有限公司

Dates

Publication Date
20260508
Application Date
20260302

Claims (7)

  1. 1. The improved die steel with high mirror polishing characteristics is characterized by comprising the following raw materials in percentage by mass: C:0.30-0.42%; Si:0.71-1.20%; Mn:0.12-0.53%; Cr:4.50-5.50%; Mo:2.01-3.02%; V:0.30-0.61%; P:≤0.012%; S:≤0.002%; 0.01 to 0.10 percent of synergistic element: the balance of Fe and other unavoidable impurities; the synergistic elements comprise 0.008-0.012% of F, 0.03-0.035% of rare earth, 0.03-0.04% of Nb and 0.002-0.003% of B.
  2. 2. The improved die steel with high mirror finish characteristics as claimed in claim 1, wherein said rare earth is a misch metal, said misch metal comprises Ce and La.
  3. 3. The improved die steel with high mirror finish characteristics as claimed in claim 1, wherein the mass fraction ratio of Ce to La is 7:3.
  4. 4. A method for producing the improved die steel with high specular polish characteristics as set forth in any one of claims 1 to 3, comprising the steps of: 1) Uniformly mixing other raw materials except raw materials of synergistic elements, and sequentially performing coarse refining and refining to obtain a mixture A; 2) Adding synergistic elements, namely adding rare earth fluoride complexing agent according to the mass fraction of the formula, uniformly mixing, adding nano ferroboron alloy powder, uniformly mixing, adding niobium iron powder, and uniformly mixing to obtain a mixture B; 3) And then casting, forging, quenching, tempering, stress relieving and polishing are sequentially carried out to obtain the improved die steel.
  5. 5. The method for producing a die steel having improved high mirror finish properties as claimed in claim 4, wherein said quenching process is carried out at a temperature of 1020 to 1050℃and said cooling process is carried out by vacuum gas quenching or oil quenching.
  6. 6. The method for producing a high mirror finish mold steel according to claim 4, wherein the tempering process is conducted at a temperature of 500 ℃.
  7. 7. The method for producing a high mirror finish mold steel according to claim 4, wherein the destressing temperature is less than 300 ℃ and the cooling method is furnace cooling at 500 ℃ or less.

Description

Improved die steel with high mirror polishing characteristic and preparation method thereof Technical Field The application relates to the technical field of metal materials, in particular to improved die steel with high mirror polishing characteristics and a preparation method thereof. Background In the technical field of metal materials, the die steel is used as a key base material for die manufacture, and the quality of the performance plays a role in die manufacture and the quality and production efficiency of related industrial products. Along with rapid development of technology and continuous upgrading of industrial production, various industries have raised higher and higher requirements on the precision, surface quality, service life and the like of the die. In high-end manufacturing industries such as automobiles, electronics, aerospace and the like, the mirror polishing property and corrosion resistance of a mold directly influence the appearance, optical performance and environmental resistance of a product. For example, in the manufacture of automobile lamps, a high-mirror-surface mold can ensure that an injection molded transparent plastic lens or a metal reflecting cup has excellent optical performance, so that the lighting effect and the aesthetic degree of an automobile are improved, and in the manufacture of an electronic equipment shell, the mold can be ensured to be used for a long time under severe environments such as humidity, high temperature and the like without being corroded due to good corrosion resistance, so that the dimensional accuracy and the surface quality of a product are ensured. Therefore, improving the mirror polishing property and corrosion resistance of die steel has become an important subject of research in the field of metal materials, and continuous development and innovation of related technologies are continuously pushing the die manufacturing industry to move toward high precision, high efficiency and high reliability. In order to improve the mirror polishing property and corrosion resistance of the die steel, the prior art generally adopts a mode of adjusting alloy components. One common means is to add chromium element with higher content and to match with proper amount of carbon, nickel and other elements, so as to raise the polishing effect and corrosion resistance of the material. The chromium element can form a compact passivation film on the surface of the die steel, and the passivation film can effectively prevent the corrosion of external medium to the die steel, so that the corrosion resistance of the material is improved. And the coordination of elements such as carbon, nickel and the like can improve the tissue structure of the material, so that grains are finer and more uniform, and further the polishing performance is improved. Another research direction is to introduce microelements such as titanium, molybdenum, vanadium and the like, and aims to further optimize the mirror quality and toughness of the die steel. These microelements can refine grains, improve the strength and toughness of the material, and simultaneously help to improve the polishing performance of the material. The titanium element can form stable carbide, pinning grain boundary and preventing crystal grain growth, the molybdenum element can improve high-temperature strength and hardness of the material, and the vanadium element is favorable for improving wear resistance and fatigue resistance of the material. In addition, there have been some studies on attempts to further optimize the properties of die steel by adjusting the ratio of alloying elements and the order of addition. However, these conventional solutions have significant drawbacks in long-term practical use. On one hand, the die steel is easy to adsorb pollutants and difficult to clean in the processing and using processes, and the durability of the mirror surface is seriously affected. In the manufacturing process of the die, when working procedures such as electric spark machining, wire cutting and precise grinding are carried out, fine particles such as metal scraps and dust are easy to adhere to the surface due to local high-temperature oxidation and electrostatic action, and the cleaning process is complicated. In the subsequent injection molding production, organic volatile matters, siloxane residues, vapor deposition particles and the like brought by the high-temperature molten plastic, the organic silicon sealing material and the metal coating process are easy to carbonize or adhere on the surface of the cavity to form stubborn stains. Since the mirror surface is extremely smooth and does not allow mechanical scratches, frequent cleaning risks damaging the surface or secondary pollution, making it difficult to maintain the mirror quality of the mold over long periods of use. On the other hand, the mold needs to bear the alternating action of cyclic heating and cooling in the long-term use process, and the d