SU753923A1 - Cast iron with spherical graphite - Google Patents

Description

(54) SPARE GRAPHITE CAST IRON The invention relates to ferrous metallurgy, in particular to high-strength spherical graphite chuunas, doped with metsyu and pre-designated cpu manufacture of responsible machine gangs. Spherical graphite cast irons, which are soci-containing as an alloying element, are well-known and serve, in particular, for the manufacture of castings with pearl or peolitoferritic metal base structure, which results in hardening and an increase in the wear resistance of castings 1. The closest to the invention is technically and scattered the result is cast iron of the following chemical composition, wt.%: Carbon-2.5-4.5 Silicon1.5-4.5 Manganese3, O Meioao 2.0 Nickeldo 1.0 Chromzo 1.0. Titando 1, O Vanadiumdo 3.5 Cobaltdo 1, O Molybdendo 2.5 Niobiumdo 2.0 Wolframdo 2.5 Tin water 0.5 RHMdo 0.5 Magnesium to 0.1 Iron Other 2. Cast iron has high performance. The disadvantage of the known cast iron is low B5 viscosity and plasticity. The purpose of the invention is to increase visco-and plasticity. The goal is achieved by the fact that the iron additionally contains aluminum and catpetions with the following ratio of components, Carbon2.8-3.8 Silicon2.2-3.5 Manganese, 3-O, 9 Copper0.15-0.75 Nickel0.05-0.25 Chrom0.05-0.25 0.05-0.12 Vanadium 0.01-0.10 Cobalt 0.001-0.015 Tungsten 0, OO1-O, 015 Moppbtsen 0, OO1-O, O15 0.001-0.005 Niobium 0.0 ( 31-0.010 0.020-0.080 Magnesium 0.010-0.003 0.01-0, O5 Aluminum 0., 035 Calcium Rest Iron The content of calcium and aluminum in the composition of the proposed nodular cast iron, complements each other, has a positive effect on the structure formation and, unlike famous cast iron provide m directly in some structures, the production of perlite ferrite, mainly pearlite matrix without structurally free cement or carbides, which in a significant amount and size occur in the known iron. In addition, the structurally free macrocarbides in the known iron are located on the grain boundaries of the matrix , embrittlement of the cast iron during hardening. Found in the proposed cast iron on the electron microscope microscope, located exclusively at the price of a grain of thickened fine grained plastic The matrix does not have a brittle effect. In the isothermally hardened ferritic line, the central location in bainite grains is not inherited. Thus, the calcium and aluminum content in the nodular nodular cast iron provides an optimal combination of HIGH plasticity, viscosity and strength as directly in the cast and isothermally hardened state. The cast iron was melted in an induction furnace with an acid crucible lining. Known cast iron was used for use in the charge of calculated amounts of drinking nickel iron of the brand, type 12-10 according to TU 14-15-3-74 MFM USSR with the addition of metallic copper to the charge. The melt of this cast iron was modified with metallic magnesium with ferrosilicon and with the addition of ferroceri. . The proposed cast iron was melted using the calculated amount of bauxite titanium-bearing foundry iron of the BTML brand 3, the degree of copper alloying 2, according to TU 14-15-4-74 MFM USSR in the charge. The melt of the proposed iron was treated with a complex iron-silicon-calcium-calcium ligature of the type LCKK4r according to TU CHEMK 14-15-39-74. For tests of mechanical properties, bar samples were cast according to GOST 72 93-7Os with a wedge base size of 25 mm. Filling of bar samples was carried out in wet sand forms. Mechanical properties were determined both in the cast state and after isothermal hardening according to the mode: heating and holding in a furnace at 85 ° ± 10 ° C and hardening at this temperature in a saltpeter bath with a temperature of 330-35 ° C with holding the samples for two hours and followed by air cooling. The chemical composition of the well-known and before: married pig iron is given in table. 1, and data on mechanical properties in the cast and isothermally quenched states in Table 1. 2

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Claims (1)

Claim Nodular cast iron containing carbon, silicon, manganese, copper, nickel, chromium, titanium, vanadium, cobalt, molybdenum, niobium, tungsten, tin, magnesium, cerium and iron, characterized in that, in order to increase the viscosity and ductility at at the same time hardening castings both directly in cast and in isothermally hardened states, it additionally contains aluminum and calcium in the following ratio of components, wt.%: Carbon 2.8-3.8 Silicon 2.2-3.5 Manganese 0.3-0.9 Copper 0.15-0.75 Nickel 0.05-0.25 thirty Chromium 0.05-0.25 Titanium 0.05-0.12 Vanadium 0.01-0.10 Cobalt 0.001-0.015 Molybdenum 0.001-0.015 35 Niobium 0.001-0.005 Tungsten 0.001-0.015 Tin 0.001-0.010 Magnesium 0,020-0,080 Cerium 0.010-0.003 40 K alcium 0.015-0.035 Aluminum 0.01-0.05 Iron Rest