An iron-based metallurgical material and a method for its preparation

　　Superalloys are a special class of alloys based on iron, alloyed with various elements to enhance their high-temperature mechanical properties and corrosion resistance. Compared with nickel-based and cobalt-based superalloys, these iron-based superalloys are widely used as high-temperature structural materials in fields such as national defense, energy, aerospace, and nuclear reactors. Traditionally, the primary application area for superalloys has been aircraft engines. Although a wide variety of iron-based metallurgical grades currently exist, with the advancement of industrialization in China, demand for superalloy materials across diverse civilian industries continues to grow rapidly—far outstripping the capacity to meet the needs of industrial development. Consequently, under the existing… Iron-based metallurgy On this basis, we have developed an iron-based alloy that exhibits ideal toughness and wear resistance, along with excellent weldability, hardness, and machinability.

　　Technical highlights: In view of the aforementioned technical issues, the technical personnel have provided a… Iron-based metallurgy and its preparation method. By incorporating rare-earth composite reinforcing materials, the iron-based metallurgical alloy is subjected to multi-element alloying and then undergoes heat treatment, thereby achieving desirable hardness and mechanical properties. To accomplish these objectives, the technical solution employed for this iron-based metallurgy comprises the following raw materials in mass percentages: chromium 4.5–5.8%, silicon 0.4–0.8%, carbon 0.41–0.48%, graphene composite material 1.2–1.6%, manganese 1.0–1.5%, and tungsten 0.8–1.2%.

1. Graphene Oxide Treatment: Prepare an aqueous graphene oxide solution with a mass concentration of 2–4 mg/mL by dispersing graphene oxide powder in deionized water, followed by ultrasonic treatment for 25–30 minutes using an ultrasonic cleaner operating at 60–100 W. This yields a fully dispersed graphene oxide aqueous suspension, with the ultrasonic cleaner’s temperature set to 20–25°C.

II. Preparation of Rare-Earth-Element‑Modified Graphene: To the graphene oxide aqueous suspension obtained in Step 1, add an appropriate amount of polyethyleneimine, followed by an appropriate amount of lanthanum nitrate. After ultrasonic dispersion for 20–24 hours, reflux the mixture and cool it to 70–80°C; then continue ultrasonic treatment for 2–4 hours. Subsequently, reflux at 100–105°C for 20–24 hours, and add hydrazine hydrate (50% w/w) to allow the reaction to proceed for another 6–8 hours. Upon completion of the reaction, the uniformly mixed suspension is subjected to vacuum filtration, washing, and vacuum drying, followed by calcination at 450–500°C for 5–8 hours, yielding a rare-earth lanthanum/polyethyleneimine–graphene composite material. This iron-based metallurgical rare-earth lanthanum/polyethyleneimine–graphene composite combines the advantages of graphene and rare-earth oxides, with the incorporation of a high‑molecular‑weight polymer that enhances adhesion, thereby promoting the attachment of rare-earth elements to the graphene surface. Moreover, this composite not only exhibits graphene’s strengthening and toughening effects on the alloy but also benefits from the grain‑refining action of the rare-earth elements. Furthermore, since lanthanum does not form intermetallic compounds with iron, it can fully exploit its intrinsic catalytic and functional properties.

The preparation method for iron-based metallurgy comprises a smelting process and a heat‑treatment process. The smelting process includes the following steps: 1) Charge melting: Prepare the charge according to the mass percentages of the raw materials, heat to 1530–1550°C until all materials are completely melted, obtain a molten metal, and hold at this temperature for 5–10 minutes; 2) Refining and settling: Skim off the slag floating on the surface of the molten metal obtained in step (1), refine for 3–5 minutes, then remove any remaining surface slag and allow the melt to settle for 8–10 minutes; 3) Casting: When the temperature of the refined molten metal has cooled to 1500–1520°C, proceed with casting to produce the iron‑based alloy. The heat‑treatment process involves solution treating the smelted iron‑based alloy at 1000–1050°C for 2–4 hours, followed by aging at 500–600°C for 6–10 hours.

　　The above Iron-based metallurgy The beneficial effects are as follows: this iron-based alloy is produced through composite alloying with multiple elements, with boron and rare earth elements added as reinforcing additives. After melting and casting, it undergoes heat treatment, which enhances its toughness and wear resistance. It also exhibits excellent hardness, weldability, and machinability, while its service life is improved.