A kind of cast iron material and its production process

Abstract

The invention discloses an iron casting material. The iron casting material is prepared from, by mass, 60-80 parts of foundry return, 20-30 parts of waste steel and 10-30 parts of pig iron. The iron casting material includes, by mass percent, 2.9-3.2% of C, 3.5-4.2% of Si, smaller than or equal to 0.15% of Mn, smaller than or equal to 0.025% of P, smaller than or equal to 0.015% of S, smaller than or equal to 0.025% of Ti, smaller than and equal to 0.02-0.05% of other impurities and the balance Fe. The high-purity pig iron, the waste steel and the foundry returns are used as the raw materials, the total content of microelements in furnace burdens is better controlled, various kinds of interference during solidification is avoided due to the reduction of the total content of the microelements, the Mn content is reduced, and the Ti content is greatly reduced; in addition, due to a machining nodulizing agent, the nodularity in the iron casting material reaches the second level or higher, generation of pearlite is reduced due to sufficient solidification of Si, and the content of ferrite reaches 93% or so; and furthermore, due to solidification of Si, the strength of the iron casting material reaches 580-650 MPa, ductility reaches 21%-25%, surface hardness reaches 180-200 HB, high ductility and low surface hardness are ensured, hardness of a casting is distributed evenly, and the casting is convenient to machine.

Description

technical field [0001] The invention relates to the technical field of metal smelting, in particular to an iron casting material and a production process thereof. Background technique [0002] Ductile cast iron is treated with spheroidization and inoculation, and the graphite form is spherical cast iron, which effectively improves the mechanical properties of cast iron, especially the plasticity and toughness, so as to obtain higher strength than carbon steel. According to different shapes, nodular cast iron The inclusion in: 1. Ferrite has a body-centered cubic lattice, which is an interstitial solid solution of carbon dissolved in α-Fe, which is called ferrite, that is, α-Fe and the solid solution based on it, represented by the symbol F; 2. Pearlite is a eutectoid of ferrite and cementite formed by eutectoid transformation of austenite. Its form is a layered complex phase in which ferrite thin layers and cementite thin layers alternately overlap, also known as lamellar p...

AI Technical Summary

Problems solved by technology

Although it has obtained the performance of easier processing, the process is complicated, and its CE is too high at 4.7-5.3%, which easily causes graphite to float and seriously affects the quality of the casting product. The high-strength ferrite disclosed in CN 103866176 A Body ductile iron, the weight percentage of each component is (wt%): carbon: 3.64-3.78; silicon: 2.61-2.68; manganese: less than 0.25; sulfur: less than 0.018; phosphorus: less than 0.04; : 0.03-0.05%; other unavoidable impurities: less than 0.1; the balance is iron; the cost of this invention is too high, and the cost of the product is increased under the same performance. Simple casting material preparation process