SU645975A1 - Inoculant - Google Patents

Description

The invention relates to metallurgy and mechanical engineering and can be used in the production of iron castings with enhanced physical and mechanical properties. Known modifier for cast iron of the following composition, wt.%: Silicon 40-55 5-10 Manganese 5-15 Zirconium 0.1-2.0 Aluminum 0.5-3.5 Calcium Rare-earth 3-10 metals 0.5-3, 5 Yttrium t Else ij. Iron The disadvantage of this modifier is that it eliminates chillings in iron castings only with a significant additive of 0.4-0.8% by weight of the liquid metal, i.e. in the amount used in the microalloying of cast iron. The increased amount of the modifier introduced leads to a decrease in the temperature of the melt, the enlargement of the structure and an increase in the porosity of the iron. The closest to the invention is a modifier of the following composition, wt.%: Some kind of doped up to the time that the nit is 25 25 Silicon 50-55 Zirconium 18-25 Manganese 8-10 Iron Remaining 2. The known modifier has not eliminated the formation structure-free bids in gray iron and chill in bone cast-iron castings and when the sulfur content in the metal is 0.07-0.12%, it does not produce stable ultatas even with its increased course to 0.7-1.0%. The aim of the invention is to predict the formation of structural-carbides and increase its mechanical properties in the fused state. The goal is achieved by the fact that the proposed modifier additionally contains barium, rare-earth metals and strontium when following the ratio of components, wt.% G Silicon Zirconium Manganese Rare-earth 5-18 metals - 1-6 Strontium 0.2-5 Iron 5.8-6.3

The monoxide is introduced into the melt in a volume of 0.05-0.1% by weight of the liquid metal by one of the known methods, but preferably into the casting ladles when the metal is filled with one third of their capacity. The effect of the modification is maintained for 18-25 minutes. The higher the sulfur content in the pig iron, the greater the consumption of od 5fatopa.

The modifier is well dissolved and absorbed by the metal and provides a stable pearlite structure in castings with wall thickness of 5-80 m, m. The proposed composition of the modifier is the chemical composition of the modifier, EEC.%

contributes to the transition of interdendritic graphite into uniformly lamellar, to obtain castings without chill and to reduce the size of eutectic grains of gray cast iron of increased strength. The presence of cementite in the castings and each other, impairing the strength of the iron, was not found. The modifier can be used when casting parts of complex configuration from MF 36-56.

P & M. The effect of modifiers of the following composition on the structure and properties of cast iron was studied (see Table 1}:

Table 1

25

18.5

21.5

12

21.5

Cast iron content, weight. %: 3.33, 5 carbon, 1.4-1.7 silicon, 0.60, 9 manganese, 0.05-0.15 phosphorus, up to 0.12 sulfur, the rest of the iron melted in coke oven jarpaHKax with a capacity of 5 tons / hour and quartz crucible induction furnaces, OJM65-73

0.1

0.05-0.1 63-67

18

65

6

11.5

3,52,6

5.9 7.5

1.22.5 5.8 5. 5.8

10.2 left

bone 150 kg. The iron was modified in casting buckets 250kilogradiovyh at a temperature of 1380-1430S ..

Properties and structure of the modified cast iron are given in table. 2

Table 2

 249-269 Sorbitolite

perlite and fine graphite

241-255 Plate and

Sorbitol-like perlite, graphite

0.05-0.1 65-71

0.05

63-66

5. 0.1-1.0 61-63 (prototype)

Claims (2)

1. USSR author's certificate 530923, cl. C 22 C 35/00, 1975. 2. USSR author's certificate number 469763, cl. C 22 C 35/00, 1973.