SU1294865A1 - Cast iron - Google Patents

Abstract

The invention relates to metallurgy and can be used for the manufacture of castings operating under conditions of wear and bending loads in the temperature range of 243-303 K. The goal is to increase the flexural strength, wear resistance and flexural endurance. New cast iron contains, in May.%: Carbon 2.9-3.4; silicon 1.6-2.3; manganese 0.7-1.7; REM 0.02-0.07; nitrogen 0.03-0.08; calcium 0.02-0.05; boron 0.002-0.03; antimony 0.1-0.2; aluminum 0.07-0.1; copper 0.10-0.35 and iron else. Additional input to the composition of cast iron Sb, Cu, and A1 ensures the twisting of the fatigue limit from 153 to 278-288 N / m at 243 K and an increase in the deflection boom from 6 to 9-11 mm at 243 K. Table 2. with (L to with 4 00 O5 Oi

Description

The invention relates to metallurgy, in particular, to the development of cast iron compositions for castings operating under conditions of wear and bending loads in the temperature range of 243-303 K.

The purpose of the invention is to increase the ultimate strength, bending, wear resistance and the limit of endurance when bending.

The essence of the invention is the additional input into the composition of cast iron Cu, A1 and Sb.

Additional introduction of antimony in an amount of 0.1-0.2 wt.% Strengthens the solid solution, increases the content of perlite and the homogeneity of the structure and crushes the matrix, which contributes to improving the wear resistance, the limit of endurance during bending and the deflection and their stability. When the content of antimony is up to 0.1 wt.%, The structure homogeneity and stability of the flexural endurance and deflection are insufficient, and the upper limit of the content of antimony is limited by the concentration (0.2 wt.%), Above which the homogeneity of the structure decreases. grain boundaries and plastic properties, which leads to a decrease in the stability of the deflection boom, betrayed endurance during bending and other mechanical properties.

Aluminum in the amount of 0.07–0.1 wt.% Appears to have a hybridizing and deoxidizing effect, crushes the graphite inclusions and stabilizes the structure, which provides increased stability of the bands. deflection and endurance at bending. The stability of the structure, deflection and endurance at

Boron in the amount of 0.002-0.03 wt.% Forms graphitization centers, being an effective surface-active modifier that contributes to an increase in the stability of the structure, deflection and mechanical properties.

When the boron concentration is more than 0.03 wt.%, The bo content increases; the bend with the aluminum content up to 0.07 wt.% Is insufficient, and at a concentration of more than 0.1 wt.%, The porosity increases, the structure homogeneity decreases and the stability of the endurance limit decreases. bending and plastic properties, especially in the interval of 50 Reads on the grain boundaries, which reduces the negative deflection temperature and fatigue limit

In cast iron, the concentration during bending is increased, rare earth metals to 0.02–0.07 wt.% With the aim of increasing the stability of perlite to increase the shape factor 55 with the practice of using graphite and the stability of mechanical nonstable cast irons, and the concentration of properties of the silica is limited to 1 , 6-2.3 wt.%.

When the content of rare-earth metals to 0.03 wt.% With an increase in the silicon content in the structure, a lamellar-dominated more than 2.3 wt.% Enlarges the structure. The carbon content is taken in an amount of 2.9-3.4 wt.% In the corresponding graphite, which reduces the mechanical properties , and at a concentration of more than 0.7 wt.%, chill is increased and the stability of mechanical properties is reduced.

Calcium in the amount of 0.02-0.05 wt.% Micro-matrixes, clears the grain boundaries from sulphides and other non-metallic inclusions and increases

deflection and endurance limit both at room and at low temperatures. At a concentration of up to 0.02 wt.%, The micro-effect is weak and there is no significant increase in the stability of mechanical properties at negative temperatures, and at a concentration of more than 0.05 wt.% Calcium does not dissolve completely in the matrix, increases the amount of non-metallic inclusions and reduces the flexural strength and ductility of cast iron at low temperatures.

Copper in the amount of 0.10–0.35 wt.% Contributes to the complete perlitization of the matrix, crushes the structure of the metallic base and increases its stability over a wide temperature range, which contributes to

stability of the limit of endurance in bending and mechanical properties at low temperatures. When the concentration of copper is up to 0.10 wt.%, Grinding the structure, increasing the wear resistance and stability of the plastic properties at negative temperatures are insufficient, and at a copper concentration of more than 0.35 wt.%, Liquation processes increase, and the stability of the structure of mechanical properties is reduced.

Boron in the amount of 0.002-0.03 wt.% Forms graphitization centers, being an effective surface-active modifier that contributes to an increase in the stability of the structure, deflection and mechanical properties.

When the boron concentration is more than 0.03 wt.%, The content of bo

Reads on the grain boundaries, which reduces the deflection and endurance

when bent, with the practice of using wear-resistant cast irons, and the concentration of silicon is limited to 1.6-2.3 wt.%.

The carbon content is taken in an amount of 2.9-3.4 wt.%, Respectively, the technological properties and the stability of the mechanical properties are reduced, and with a decrease in the silicon content of less than 1.6 wt., The chill is increased.

Manganese in the amount of 0.7-1.7 May increases the dispersion of perlite, plastic properties and the limit of endurance during bending. At manganese concentrations up to 0.7 mPa, an insufficient limit of bending endurance is noted, and with an increase in the manganese content of more than 1.7 wt.%, The stability of the structure and mechanical properties at negative temperatures decreases.

Cast iron is smelted in electric arc furnaces with overheating of melts up to 1823 K. Refining, carburizing and microalloying operations with copper and nitrated ferromanganese are carried out directly in an electric furnace, and modifying with ferroboron, silicocalcium, rare earth metals and aluminum - at 169–3–3–3.93–3783–375 modifying, at mod. and the modifying components are,%: calcium 58-63; nitrogen 76-85; copper 84-89; boron 91-96 and rare-earth metals 48-56. Casting iron to obtain process samples and thin-walled wear-resistant castings is carried out in sandy forms in a moist manner.

AL

Known cast iron contains 0.02Z strontium.

4865

In tab. 1 shows the chemical composition of the cast iron experienced melts, and table. 2 - mechanical properties of cast iron in castings.

As can be seen from the table. 2 arrow deflection, tensile strength and endurance when bending in the proposed iron is higher and more stable than the known, especially at negative 10 temperatures.

Claims (1)

Invention Formula Cast iron, containing carbon, silicon, manganese, nitrogen, rare earth metals, boron, calcium, and iron, is, in that, in order to increase the flexural strength, wear resistance and bending endurance, it also contains antimony, copper and aluminum in the following ratio, wt.%: 25 thirty Table 1 452 734 785 772 356 486 506 494 tl 13 12 Editor N. Lazarenko Compiled by N. Kostornaya Tehred I.Popovich Proofreader G. Reshetnik Order 565/29 Circulation 605 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 t "l and f 212 153 227 4.6 230 235 228 278 288 279 232,245 241 .2 0.9 1.0 Subscription