SU697588A1 - Alloy - Google Patents

Description

The invention relates to ferrous metallurgy and foundry, in particular to the manufacture of master alloys for obtaining wear-resistant cast iron for casting engine sleeves. Known ligature for cast iron 1. of the following composition, wt.%: Carbon 0.1-2.5 Silicon 10.0-20.0 Chromium 15.0-20.0 Vanadium 20.0-45.0 Nickel 15.0- 35.0 Copper 0.1-10.0 Iron - Else. The main disadvantages of this alloy are the high melting point, the average degree of assimilation and the relatively weak effect on the microstructure and properties of the pig iron being processed. In the manufacture of castings such as engine liners in metal molds, this ligature does not prevent the loss of structurally free cementite and does not provide high anti-friction properties. The aim of the invention is to develop a composition of a ligature, which ensures a decrease in the temperature of its melting temperature and an increase in the degree of assimilation, weight of the form and reduction of ramgraffit inclusions, preventing the precipitation of structural-free cementite and increasing physical activity. the metal properties of the metal, especially the friction ones. The goal is achieved that the proposed ligature additionally contains manganese, antimony, iy, strontium and rare earth allah in the following ratio of ponents, wt.%: Chrome 8.0-20.0 18.5-22.5 Silicon Nickel 6.5- 15.0 Copper 5.0-12.5 Carbon 0.3-3.5 Manganese 0.5-10.5 2.0-10.0 Antimony Barium 0.05-1.5 Strontium 0.05-1, 25 Rare-earth0, 05-1.5 No metals Iron Else The addition of manganese to the master alloy helps to reduce the melting point and increase dispersion perperitol. When the content of manganese

less than 0.5%, it does not affect the microstructure and properties of Cast Iron, and with an increase in its content of more than 10.5%, no noticeable improvement in the microstructure is observed, and the intrication properties of cast iron begin to decrease.

The optimum content in the ligate, antimony contributes to the ierlitization of the metal matrix of the microstructure, the formation of a complex carbideosymphocytic eutectic, leading to an increase in the antifriction properties of cast iron. Entering into the composition of cast iron less than 2.0% antimony does not have a noticeable effect on the temperature of its melting and assimilation, it has little effect on the improvement of the microstructure and improvement of the properties of cast iron. With an increase in the antimony content of more than 10.0%, the amount of eutectic increases significantly, the cast iron becomes brittle and its strength and antifriction properties decrease.

Barium, strontium, and rare earth metals (SEM) are introduced into the composition of the alloy to increase its modifying effect and suppress the deposition of structurally free cementite. The lower limit on the content of barium 0.05% is determined by the beginning of its modifying (its action). When barium content is more than 1.5%, its effect on the shape and size of graphite inclusions is significantly reduced, which practically leads to a small change in strength and anti-corrosion properties. oh stf.

Strontium content less than 0.05% does not affect the microstructure and properties of cast iron. Optimal

the content of strontium, which provides for the suppression of deposition of structurally free cementite, the improvement of the microstructure and the improvement of the properties of cast iron, is 0.05-1.25%. With a higher content of strontium

The effect on the properties of cast iron is practically not felt.

Entering into the composition of the rare-earth metal ligature, along with their positive effect on the stabilization of pearlite and the suppression of the formation of structurally free cement, leads to a decrease in the size of carbideosyntho-phosphorus eutectics. When the content of rare-earth metals in quantities less than 0.05%, no effect on the microstructure and properties of the cast iron is detected. With an increase in the content of rare-earth metals more than 1.5% of its effect on reducing the size of the eutectic inclusions decreases and as a result, a decrease in strength and antifriction properties is observed.

Example. The smelting of ligatures of different composition is carried out in an induction furnace brand MGP-102. Chemical cocvaB., Melting point and degree of assimilation of the investigated master alloys of different composition are given in Table. 1. From the data table. 1 shows that the ligatures 1 and 11 correspond in composition to the known ligature. Ligature 111 contains less than the proposed composition, chromium, silicon, nickel, copper, barium and rare-earth metals, and ligature IX - more chromium, nickel, cypbN4j and rare-earth metals and less manganese. Ligatures with the designation IV-VII1 correspond to the composition ligature of the proposed with different content of elements included in it.

Table 1

Continuation of table 1

laziness, ° С 1390 1385 1400 1360 1365 The degree of assimilation by the iron at 1350-1380 ° С,% 72-76 70-75 68From the data in Table. 1, it can be seen that the ligature of the proposed composition has a lower melting point compared with the known one, and this provides an increase in its absorption rate from 70-76% to 76.5-87.5%.

To study the effect of the ligatures of all the compositions on the microstructure and properties of the initial cast iron in the furnace DSP-0.5, the cast iron is smelted of the following chemical composition, wt.%: 3.27-3.32 carbon, 1.64-1.67 silicon, 0.82-0.86 manganese, 0.11-0.14 chromium, 0.06-0.08 nickel, 0, .09 copper, 0.07-0.08 phosphorus and 0.035-0.04 sulfur.

15.4 15.8 16.4

15; w

15.6 16.1 15.8 16.5 16.3 10.9 18.1 76.5- 7982 82.5 74.5

After melting, the cast iron is superheated to a temperature of 1440 ± 10 ° C, then 100-120 kg portions are poured into the ladle, at which overflow from which into a smaller cast iron ladle with a temperature of 1375-L390C it is processed by ligatures of various kinds.

composition. IfO is used for cast iron treatment; 2.0 and 3.0% ligatures.

The effect of varying amounts of the UR league of compositions 1-1X on the amount of chillbing of the wedges, the microstructure and physical and mechanical properties of cast iron is given in Table. 2..

{Table 2

Gr7, Gf5, Gd6

P-95 06

8.0

1.06 Grb, GF5, Gd5 1.09 6.0 1.17 4.5

P-95, G06 8: About 1.05 Grb, GF5, Gd5 1.07 6.5 5.0 1D

P-95, G06 1.06 8.0 Grb, GF5, Gd5 1.08 6.3 4.6 1.12

Claims (1)

P-95, G04 1.14 5.0 Gr5, GF4, Gd5 3.3 1.2 1.2 1.2 1.29 1340 1335 8079, 585, 5 86 From the data in Table. I saw that the optimal consumption of ligature is in the range of 1.5-2.0%. With a greater consumption of a noticeable improvement in the microstructure and enhancement of the properties of the iron, it does not occur. Comparison of the obtained data shows that the use of the ligature of the composition proposed allows, compared with the known ligature, to reduce the chill off value on the wedge from 8-4.5 to 5.2-2.6 mm, to obtain a finer graft. Graphite, to increase the tensile strength at stretching from 21.8-23.4 to 23.2-26.2 kgf / mm, increase the conditional yield strength from 15.3-16.4 to 16.1-18.5 kgf / mm, increase the hardness from 184 -195 to 192-212 kgf / vsyi and relative wear resistance from 1.06-1.12 to 1.13-1.38. So1; it is clear to the preliminary calculation of the economic efficiency of increasing the percentage of mastering the master alloy of the proposed composition and improving the properties, especially anti-friction, of cast iron will be 1.38-2.16 rubles. per ton of suitable castings such as engine liners.) Studies show that the proposed ligature, in particular, can be used in the form of a mechanical mixture of alloys containing all the elements that make up the ligature in the required quantity. On the Continuation of the Table of Examples, a mechanical mixture of alloys may consist of: ferro silicon of the grades FSH18-FSHZO 27.5 - 42.5,. silicomanganese SMP 14-SMP-17-20, 0-35.0 grades and one or several alloys (22.5-42.5) containing nickel, copper, antimony, barium, strontium, rare-earth metals and impurities in necessary quantities. A preliminary calculation shows that by reducing the consumption of alloying elements, increasing the mastering of the master alloy and increasing the physical and mechanical properties, the economic efficiency will be 3.62-4.18 rubles per 1 ton of usable castings. Invention Ligatures containing chromium, silicon, nickel, copper, carbon and iron, characterized in that, in order to decrease the melting temperature, increase the degree of its absorption, prevent the loss of structurally free cementite and improve the physicomechanical properties of cast iron, it additionally contains manganese, antimony, barium, strontium and rare earth metals with the following ratio of components, wt.%: Chromium 8 20 Silicon 18.5-22.5 6.5-15.0 5.0-12.5 0.3-3.5 0.5-10.5 0.2-10.0 0.05-1.5 0.05-1.25 Rare earth metals 0.05-1.5 Iron Rest Information sources, taken into account in examination 1, USSR Copyright Certificate  417520, class C 22 C 35/00, 1974.