High-strength spheroidal graphite cast iron for thick-walled casting die

Abstract

The invention discloses high-strength spheroidal graphite cast iron for a thick-walled casting die, which comprises the following main components in percentage by mass: 3.20 to 3.50 percent of C, 1.90 to 2.20 percent of Si, 0.20 to 0.50 percent of Mn, 0.40 to 0.60 percent of Cu, 0.40 to 0.80 percent of Mo, 0.60 to 0.80 percent of Ni, less than or equal to 0.06 percent of P, less than or equal to 0.03 percent of S, 0.02 to 0.05 percent of Mg, less than or equal to 0.07 percent of Re and the balance of Fe and other inevitable impurities. The as-cast mechanical properties of the spheroidal graphite cast iron are that: sigma b is more than or equal to 750MPa, sigma 0.2 is more than or equal to 520MPa, delta is more than or equal to 3 percent, and Brinell hardness is 190 to 240; the mechanical properties of the normalized, hardened and tempered spheroidal graphite cast iron are that: the sigma b is more than or equal to 1,000MPa, the sigma 0.2 is more than or equal to 900MPa, the delta is more than or equal to 2 percent, and the Brinell hardness is 260 to 300; and the material has high strength, hardness and elongation, has uniform section hardness and structure after the material is hardened and tempered when used for a large-section die, and can meet the requirement of the actual use working condition of the large-section die with the wall thickness of more than 200mm.

Description

technical field [0001] The invention belongs to the technical field of casting materials and relates to a high-strength nodular cast iron used for molds of thick-walled parts. Background technique [0002] The most fundamental principle of mold design is to meet the requirements of the use target. These requirements include the main mechanical properties such as strength and toughness and other related process properties. For molds, compared with alloy steel and cast steel, ductile iron has higher strength, toughness and wear resistance, and its comprehensive performance is good. At the same time, it is suitable for mass production due to its low cost. In addition, there are precedents of using ductile iron materials such as large stamping dies and crankshafts at home and abroad. Patent Publication No. CN1506485 titled "High-strength Alloy Ductile Iron Crankshaft New Material and Its Production Method" discloses a high-strength alloy ductile iron crankshaft material. 2.04-...

AI Technical Summary

Problems solved by technology

At the same time, due to the redistribution of solute elements during solidification, there will be a series of problems such as serious element segregation, intergranular carbides, and anti-whitening. As a result, the mechanical properties of ductile iron will deteriorate, especially the elongation and plasticity. reduced, thus restricting the popularization and use of large-section ductile iron

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