SU821522A1 - Master alloy - Google Patents

Description

I

The invention relates to foundry and can be used in the production of pig iron.

Known ligature 1 for cast iron of the following composition, wt.%:

Silicon 23-25

Iron5-7

Aluminum Else

Cast iron castings obtained using this ligature, have an increased tendency to cracking.

Closest to the invention to the technical essence and the achieved e (} effect is a ligature of the following composition, wt.%:

Silicon1O-16

Iron5-9

Aluminum Else

When using this composition of ligature for processing pig iron in an amount of 1-2% of the weight of the cast iron due to the high content of aluminum in it, inclusions of cementite are observed in the cast iron structure, which are painted when the parts are working under conditions of friction. Therefore, it is advisable to use it to obtain castings that are cooled at low speeds, the production of thin-walled casting does not ensure the production of castings with high wear resistance and with preservation of good workability of the metal.

The purpose of the invention is to develop the composition of the master alloy for cast iron, which increases its mechanical properties of wear resistance.

The goal is achieved by the fact that hafnium, boron and carbon are added to the composition of the ligature at the following ratio of component, wt.%: Aluminum5-1O

Silicon iO-50

Hafnium1.0-2O

Bor, 1, O-5, O

. Carbon, 2-5, O

The remaining Iron 38 ha nor on the properties of cast iron, and with an increase in its amount above 2O, hafnium is concentrated along the grain boundaries, which adversely affects the properties of the metal. Entering into the composition of the ligature of boron is due to the fact that s leads to the formation aemom iron composite carbide-bsridnoy eutectic decoupling recovered as a separate phase having a high abrasion resistance. When the content of boron in the master alloy is less than 1% karbndo bfndna-phase and out not ofazuets

The compositions of ligatures, weight.

 n /

The rest is 13.5-5ZO1 5

1010 ..201

6,515,89,42,5

9,726,518, .63,9

From the data table. 1 shows that the ligatu-composition, wt.%: Carbon 3,36,

ra with index. 1 corresponds to known-silicon 1.42, manganese O, 91, sulfur 0.02

mu, and alloys 2-5 - ligature offer and phosphorus O, O4. The treatment of the pig iron of the ligamic composition. The courses are carried out in buckets at 138O +

Investigation of the effect of ligatures on the proper-, weight of liquid iron.

The properties of cast iron are carried out by means of out-of-furnace table-B. 2 shows the properties of cast iron,

processing of the original cast iron next chi-treated ligatures of compositions 1-5.

Spreadsheets

Claims (2)

. The ligature flow rate is 1% of the 22. The cast iron's wear resistance is low. When a boron ligature contains more than 5%, the brittleness of the iron increases and its workability deteriorates. Introduction the carbon ligature in the amount of 0.2-5%, together with silicon, helps to eliminate the formation of primary carbides, reduce shrinkage porosity and shrink holes in the iron. The lower limit of carbon in the ligature (0.2%) is limited by the technological conditions of smelting the ligature. When more than 5% of carbon is contained in the ligature, it melts and melts into the slag during smelting. PRI me R. In laboratory and experimental-production conditions, the compositions of master compounds given in Table 2 were made and tested. 1. 5S21S Verification of this composition of the master alloy shows its greater effectiveness in obtaining iron with high physical and mechanical properties and wear resistance. Thus, the tensile strength of cast iron under 5 stretching increases by 8 kgf / mm, the flexural strength by 12 kgf / mm, and wear resistance by 8O%, while maintaining equivalent hardness. A preliminary calculation of the expected economic efficiency is 9–11 p in the production of 1 ton of annual castings due to the physical and mechanical properties of cast iron 1.35 times and wear resistance 1.8 times. The invention The ligature, containing aluminum, silicon and iron, is distinguished by the fact that, in order to improve the mechanical properties and wear resistance, it additionally contains hafnium, boron and carbon in the following ratio of components, wt.%: Aluminum 5-1O Silicon 1O -5O. Hafnium1, O-2O Bor1.0-5.0 Carbon0.2-5, O Iron. Others Sources of information taken into account during the examination 1.Avtsskoe certificate of the USSR № 422787, cl. C 22 C 35 / OO, 1972. 2. USSR author's certificate number 535368, cl. C 22 C 35 / OO, 1977.