Alloyed gray cast iron resistant to high-temperature aluminum and zinc liquid corrosion and its smelting process

Abstract

The invention belongs to the technical field of metallurgy, and particularly relates to high-temperature aluminum and zinc liquid corrosion resisting alloyed gray pig iron and a smelting technology thereof. The high-temperature aluminum and zinc liquid corrosion resisting alloyed gray pig iron specifically comprises following elements including, by weight percent, 3.1%-3.3% of C, 1.9%-2.2% of Si,0.8%-1.0% of Mn, smaller than or equal to 0.06% of P, smaller than or equal to 0.03% of S, 0.15%-0.3% of Cr, 0.05%-0.15% of Ni, 0.05%-0.2% of Cu, 0.15%-0.25% of Mo, 0.02%-0.04% of light rare earth andthe balance Fe. Through the synergistic effect of electrolytic copper, chromium, nickel, ferromolybdenum, the light rare earth and other alloy elements, the content of pearlite in a base body is increased, the pearlite layer sheet thickness and sheet distance are obviously reduced, base body structure grains are fine, a graphite sheet formed through one-time crystallization is fine and disperse,a small number of ferrite base body structures are easily obtained, hardness can be better reduced, material toughness is improved, the metallurgical quality is good, and strength is high.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to an alloyed gray cast iron resistant to high-temperature aluminum and zinc liquid corrosion and a smelting process thereof. Background technique [0002] Gray cast iron refers to cast iron with flake graphite. The main components are iron, carbon, silicon, manganese, sulfur and phosphorus. It is the most widely used cast iron, and its output accounts for more than 80% of the total output of cast iron. It has wear resistance, heat resistance, Oxidation resistance, corrosion resistance, acid and alkali resistance and good shock absorption, at the same time, compared with other alloys, it has the advantages of low melting point, good filling performance, good processability, simple production facilities and molding process, and low cost; suitable for Large castings with high requirements and different cross-sections. With the development of industry, the requirements for the perf...

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Problems solved by technology

With the development of industry, the requirements for the performance of gray cast iron are getting higher and higher, not only requiring it to have higher mechanical properties, but sometimes it is also required to have some special properties, such as high wear resistance, heat resistance and corrosion resistance, etc. ;Add some alloying elements to the molten iron of gray cast iron to obtain alloy cast iron with some special properties, but most of them are brittle, low in strength and poor in mechanical properties

[0003] The high-strength high-temperature-resistant and corrosion-resistant cast iron disclosed in Chinese Patent No. CN201110205156.X has the following chemical composition: C: 2.7-2.9%, Si: 1.5-1.8%, Mn: 0.6-0.8%, Al: 4.0-6.0%, Cu: 1.5-1.8%, Mo: 0.4-0.5%, Cr: 1.0-2.0%, P≤0.05%, S≤0.05%, the balance is Fe; but due to the addition of a large amount of aluminum, the casting performance is poor; Another example is Chinese Patent No. CN201310130200.4 which discloses a eutectic graphite gray cast iron continuous casting profile and its manufacturing method, which is prepared from the following raw materials according to the stated mass percentage: C: 3.40%-3.60%, Si: 2.4% -2.9%, Mn: 0.6%-1.0%, P: 0.08%-0.15%, S: ≤0.07%, Ti: 0.06%-0.20%, Cu: 0.3-0.80%, Fe: 91.5%-93%, each The total amount of raw materials is 100%; however, due to the high silicon content, it has a metallographic structure of flake graphite and ferrite, resulting in hard and brittle material properties and low mechanical properties; secondly, the two patents prepared above Cast iron has high hardness and low toughness, is not resistant to impact wear, has poor temperature resistance and corrosion resistance in high-temperature aluminum and zinc liquids, has different metallographic structures in cast iron, unstable mechanical properties, and incompletely graphitized carburizing The body will undergo graphitization under the high temperature conditions of immersion plating, accompanied by volume expansion, and when it is subsequently cooled, the expanded volume will shrink sharply, resulting in greater internal stress, which will cause cracks in the matrix structure of cast iron parts, so It cannot be used for surface modification in the "hot-dip aluminum, zinc" process, and is not suitable for casting castings such as sinking rolls, stabilizing rolls, correcting rolls, and bearing housings

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