SU1323602A1 - Mixture for alloying and inoculating cast iron - Google Patents

Abstract

The invention relates to the field of metallurgy, in particular to the search for compositions of master alloys for the processing of pig iron. The aim of the invention is to increase wear resistance, corrosion resistance and reduce chill ,. The proposed mixture for alloying and modifying cast iron contains, in wt%; aluminum 15-25, boron nitride 2.5-7.5, titanium nitride 15-30, iron else, The use of the proposed mixture makes it possible to increase the performance properties of iron castings.

Description

The invention relates to foundry 3, in particular, to the treatment of iron in the process of producing castings.

The purpose of the invention is to improve wear resistance,: corrosion resistance and chill reduction.

The proposed mixture contains, May,% Aluminum J5-25

Boron nitride 2J5-7, 5

Titanium Nitride 35-30 Iron Other

Additional input in the composition of the mixture of titanium nitride in the amount of 5-30% contributes to improving the wear and corrosion resistance of the treated iron. When interacting with the liquid melt, titanium nitride promotes the formation of complex titanium and carbonitride, and iron, thus increasing the service properties of spanga. The introduction of nitride, titanium to a mixture of less than 15% does not allow to obtain castings with high operating properties.

The introduction of titanium nitride into the mixture by more than 30% increases chilling in the cast iron castings. The introduction of boron nitride in the composition makes it possible to improve the performance properties of cast iron spalls. When boron nitride is introduced into the mixture, less than 2.5% of the influence on the service properties is practically: is affected. With an increase in boron nitride content of more than 7.5% in the structure

an increased cement content is observed, which negatively affects the physicomechanical properties of the pig iron produced,

Introduction to the composition. A mixture of aluminum. allows you to change thermodynamic activity of carbon, facilitating the process of graphitization and spheritization of cast iron,

The graphitizing effect of aluminum in the smelting of cast iron is associated with the formation of dispersed parts of aluminum carbide alumina, which are the centers of crystallization of graphite. The use of aluminum as a graphitizer makes it possible to reduce the silicon content in the pig iron from 2.8 to 2%. Decreased silicon in the pig iron favorably affects the shape of the graphite inclusions — the amount of interstitial point graphite decreases sharply. TaKofi character treason-236022

Neither the form of graphite further facilitates the decomposition of austenite to perlite.

This effect begins to show S with an aluminum concentration in the alloy not lower than 15%. An increase in the aluminum content above 25% leads to the formation of oxide films in the iron and a deterioration in the properties of the iron. 10 Example., Dry ground crushed mixture components are metered and mixed until a homogeneous mass is obtained.

The effectiveness of the mixture for doping and modifying pig iron was tested on cast iron containing, in wt%:

Carbon3.6

Silicon2j8

Manganese0,6

20 Sulfur0.03

Phosphorus0.05

The cast iron was smelted in a 40 kg induction furnace. The alloying and modification was carried out at 1380- 25 1420 ° С by immersing the ligature on the bottom of the ladle before the release of cast iron,

The amount of injected mixture is 1% by weight of the metal. The ratio of elements in the proposed alloy for 30 alloying and iron is selected in such a way that a high alloying and modifying ability of the alloy is ensured during the treatment of the iron.

JJ Tables 1 and 2 show the composition of the alloys and the properties of the pig iron produced, respectively.

The sensitivity of pig iron to chill bleach 40 was estimated by the maximum thickness of the bleached layer of the technological wedge sample molded into a wet sand-clay form,

In order to study the wear resistance 5 and the corrosion-resistant STOIK-OSTR, those were cut out from blanks in order: 1 years.

Wear resistance tests were carried out on a Skoda-Savvina type machine with a load of 15 kg to a rotational speed of 50 carbide, 1 rpm 500 rpm.

 and with n -

Corrosion Resistance Evaluated

for weight loss of specimen O 10 and h 10 mm in a 20% HC1 solution at 55–18 ° C, test time 20 h,

jteajiHs given data shows that the application of the proposed

313236024

the mixture allows to increase the wear resistance-corrssx1:.; oG; coyote died tepm

bone and corrosion resistance of chu1 y-chill, it additionally contains

ng1 and L-.i3HTb were selected as nitrite t-gtana, and as a borsoder: pschy -: -., -. . ,;, - boron nitride at the Formula 5i 3 about b e te e nk -

A mixture for alloying and modifying cast iron, containing an aluminum-iOfflj borosoderl ashda element and iron, characterized in that, in order to improve wear resistance;

ten

with pedagogue, .g-1, - components,

wt%:

AluminumI5-25

Boron nitride 2,5-7,5

Titanium Nitride 15-30 Iron Other

Famous

140

Proposed

Order 2934/31

THpajK 604Subscribe

VINITI State Committee of the USSR

for inventions and discoveries 1 13035, Moscow; Zh-35 .. Raushsk nab., D.4 / 5

Production and printing company GL, Zhgorod, Proektna str., 4

: pschy -: -., -. . ,;, - boron nitride at

with pedagogue, .g-1, - components,

wt%:

AluminumI5-25

Boron nitride 2,5-7,5

Titanium Nitride 15-30 Iron Other

Table 1

20

table 2

Claims (1)

Formula Invented and A mixture for alloying and modifying cast iron containing aluminum, a boron-containing element and iron, characterized in that, in order to increase wear resistance, corrosion resistance and reduce bleaching, it additionally contains titanium nitride, and as boron-containing - · Η · Μ '.. · - a - boron nitride in the following with the' mixing of the components, ma with D: Aluminum 15-25 Boron Nitride 2.5-7.5 Titanium Nitride 15-30 0 Iron Rest