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CN-122013056-A - Steel for small-size steel balls for mine grinding and preparation method of small-size steel balls

CN122013056ACN 122013056 ACN122013056 ACN 122013056ACN-122013056-A

Abstract

The invention relates to the field of metal materials, and discloses steel for a small-size steel ball for mine grinding and a preparation method of the small-size steel ball. The steel ball steel comprises ：C：0.4%~0.9%,Mn：3.0%~5.0%,Si：1.4%~1.8%,Cr：0.8%~1.3%,Ni：0.3%~0.6%,Mo：0.2%~0.4%,V：0.15%~0.25%,Nb：0.02%~0.06%, the balance of Fe and unavoidable impurities, and the contents of Mn, V and Nb need to be controlled cooperatively. The small-size steel ball is forged and hot rolled and is matched with non-heat-preservation graded quenching and cryogenic treatment. The steel ball component and the preparation process realize low-temperature martensitic transformation, and a fine and uniform martensitic structure is obtained, so that the steel ball has high hardness, strong impact toughness and excellent impact fatigue resistance.

Inventors

  • ZHANG HENGYI
  • SHENG ZHENDONG
  • Tan Linhao
  • CUI QING

Assignees

  • 成都先进金属材料产业技术研究院股份有限公司

Dates

Publication Date
20260512
Application Date
20260415

Claims (10)

  1. 1. A steel for small-sized steel balls for mine grinding is characterized by comprising the following components ：C：0.4%~0.9%,Mn：3.0%~5.0%,Si：1.4%~1.8%,Cr：0.8%~1.3%,Ni：0.3%~0.6%,Mo：0.2%~0.4%,V：0.15%~0.25%,Nb：0.02%~0.06%, in percentage by mass, the balance being Fe and unavoidable impurities, and , Wherein [ Mn ] is the mass percentage of Mn contained in the steel, [ V ] is the mass percentage of V contained in the steel, and [ Nb ] is the mass percentage of Nb contained in the steel.
  2. 2. The steel for small-sized steel balls for mine grinding according to claim 1, wherein the steel comprises the following components ：C：0.5%~0.7%,Mn：4.0%~4.5%,Si：1.5%~1.7%,Cr：0.9%~1.1%,Ni：0.3%~0.5%,Mo：0.2%~0.4%,V：0.17%~0.21%,Nb：0.03%~0.05%, by mass percent, the balance being Fe and unavoidable impurities, and the total mass ratio of impurities is less than 0.05%.
  3. 3. A method for producing a small-sized steel ball for mine grinding, characterized in that the small-sized steel ball for mine grinding is produced by using the steel according to claim 1 or 2, the method comprising the steps of: Batching based on target components of small-size steel balls for mine grinding, smelting raw materials in a vacuum induction smelting mode, and casting into cast ingots; Heating the cast ingot and performing cogging forging to obtain a blank; heating and preserving the blank, and hot-rolling the blank into a bar blank with the diameter consistent with that of a target steel ball; rolling the bar blank into a steel ball blank with the diameter consistent with that of the target steel ball by adopting ball rolling equipment, and controlling the final rolling temperature to be above 850 ℃; Immediately placing the steel ball blank into a salt bath furnace to be cooled to 230-250 ℃, then immediately placing the steel ball blank into constant-temperature water to be cooled to water temperature, and placing the steel ball blank into a liquid nitrogen environment to be subjected to heat preservation for a preset time to be subjected to cryogenic treatment after the water cooling is finished; and heating the steel ball blank subjected to the deep cooling treatment for tempering treatment.
  4. 4. The method for producing small-sized steel balls for mine grinding according to claim 3, wherein the constant temperature water used for the water cooling is 25 to 40 ℃.
  5. 5. The method for manufacturing the small-sized steel ball for mine grinding according to claim 3, wherein the steel ball blank is kept in a liquid nitrogen environment for 5-35 min during the cryogenic treatment.
  6. 6. The method for producing small-sized steel balls for grinding mines according to claim 3, wherein the vacuum degree is controlled to be not more than 5 x 10 -3 Pa during the vacuum induction melting, and the melting temperature is 1520-1560 ℃.
  7. 7. The method for producing a small-sized steel ball for mine grinding according to claim 3, wherein the step of heating the ingot and performing cogging forging includes heating the ingot to 1060 to 1120 ℃ and then performing cogging forging, and the final forging temperature is controlled to 910 ℃ or higher.
  8. 8. The method for producing a small-sized steel ball for mine grinding according to claim 3, wherein heating and heat-preserving the blank and hot-rolling the blank into a bar blank having a diameter identical to that of the target steel ball comprises heating the blank to 1160-1210 ℃ and heat-preserving for 2-3 hours, hot-rolling the blank into a bar blank in a region of 930-1110 ℃, and air-cooling to room temperature.
  9. 9. The method for producing a small-sized steel ball for mine grinding according to claim 3, wherein the tempering treatment is carried out at a temperature of 200-300 ℃ for a heat preservation time of 1-10 hours.
  10. 10. The method for manufacturing a small-sized steel ball for mine grinding according to claim 3, wherein the diameter of the target steel ball is 10-40 mm.

Description

Steel for small-size steel balls for mine grinding and preparation method of small-size steel balls Technical Field The invention relates to the field of metal materials, in particular to steel for a small-size steel ball for mine grinding and a preparation method of the small-size steel ball. Background Grinding steel balls in a mining ball mill is the most important grinding medium consumable of the ball mill. In mine beneficiation operations, ball mills generally employ a "multi-bin ball-making" process. The steel balls can be classified into large-size steel balls (generally, the diameter is larger than 60 mm), medium-size steel balls (the diameter is about 40-60 mm) and small-size steel balls (the diameter is about 10-40 mm) according to different sizes. The large-size steel ball is mainly used for a crushing bin of the ball mill. In this bin, the material is of a larger particle size, typically the mill-entering material immediately after the crusher treatment. The large-size steel ball is characterized by large mass and strong impact force, and is mainly used for crushing and pulverizing coarse particle materials by virtue of impact crushing effect. The middle-size steel ball is usually positioned at the front section of the transition bin or the fine grinding bin, and plays a role in supporting the upper part and the lower part. When the materials are crushed to a certain fineness, the excessive impact force can cause energy waste, and at the moment, the granularity of the materials is further reduced by a mode of combining impact and grinding, so that conditions are created for efficient grinding of the small-size steel balls. The small-size steel balls are mainly applied to a fine grinding bin of the ball mill and are responsible for further grinding ores to fine granularity meeting the sorting requirement. The mine grinding working condition of the small-size steel ball is mainly low-energy impact and continuous abrasion. Unlike large-sized steel balls which are mainly impacted, the small-sized steel balls have large total surface area, higher contact frequency and area with ore and more obvious abrasive wear on the surfaces of the small-sized steel balls. In order to slow down the wear rate of the small-size steel ball, the small-size steel ball is required to have ultra-high hardness, and in order to resist low-energy repeated impact, the small-size steel ball is required to have impact toughness at the same time, so that the steel ball is prevented from being cracked. The grinding steel balls commonly used in mines at present are mainly chromium wear-resistant steel balls. The patent CN104831157A discloses a wear-resistant high-chromium casting ball, which comprises, by weight, 2-2.2% of C, 10-12% of Cr, 0.4-0.6% of Si, 0.5-0.7% of Mn, 0.5-2% of Nd, 0.1-0.5% of B, and the balance of Fe and unavoidable impurities. Although the hardness of the chromium-based wear-resistant steel ball is improved, the high-chromium cast iron ball is easy to generate carbide segregation and coarse carbide, micro-flaking or chipping is easy to generate under impact load, the alloy cost is high, and the high-efficiency and low-cost requirements of the mine small-size steel ball cannot be met. Therefore, the existing steel for small-size steel balls for mine grinding and the preparation method of the small-size steel balls still have a significant room for improvement. Disclosure of Invention The invention aims at solving the problems existing in the prior art, and the main purpose of the invention is to provide steel for small-size steel balls for mine grinding and a preparation method of the small-size steel balls. According to one aspect of the present invention, there is provided a steel for small-sized steel balls for mine grinding, the steel comprising, in mass percent, the balance of Fe and unavoidable impurities of the following composition ：C：0.4%~0.9%,Mn：3.0%~5.0%,Si：1.4%~1.8%,Cr：0.8%~1.3%,Ni：0.3%~0.6%,Mo：0.2%~0.4%,V：0.15%~0.25%,Nb：0.02%~0.06%,, and , Wherein [ Mn ] is the mass percentage of Mn contained in the steel, [ V ] is the mass percentage of V contained in the steel, and [ Nb ] is the mass percentage of Nb contained in the steel. According to one embodiment of the invention, the alloy comprises the following components ：C：0.5%~0.7%,Mn：4.0%~4.5%,Si：1.5%~1.7%,Cr：0.9%~1.1%,Ni：0.3%~0.5%,Mo：0.2%~0.4%,V：0.17%~0.21%,Nb：0.03%~0.05%, in percentage by mass, the balance being Fe and unavoidable impurities, wherein the total mass ratio of impurities is lower than 0.05%. According to another aspect of the present invention, there is provided a method for producing a small-sized steel ball for mine grinding, which is produced using the steel according to any one of the above embodiments, the method comprising the steps of: Batching based on target components of small-size steel balls for mine grinding, smelting raw materials in a vacuum induction smelting mode, and casting into cast ingots; Heating the cast ingot