SU1201342A1 - Complex additive for processing low-alloyed manganic steels - Google Patents

Abstract

The invention relates to the field of metallurgy, to steel deoxidation compositions and can be used for after-treatment of low-alloy manganese steels. The aim of the invention is to increase the reactivity of the additive, improve the quality of steel and reduce the cost of the additive by using substandard waste. The complex additive for the treatment of low-alloyed manganese steels includes the following components, mA%: industrial oils 0, chips of aluminum alloys 20.0-50.0; Chip titanium alloys 49-79,8. The proposed additive allows the use of non-ferrous metal chips instead of ferroalloys (P tal, it improves the quality and mechanical properties of steel, reduces non-metallic inclusions, 2 hp f-crystals, 1 tab.

Description

The invention relates to the field of metallurgy, specifically to the composition of alloys for the deoxidation of steel. It can be used for aftermath processing of low-alloyed manganese steels. The complex additive can be used to modify and deoxidize low-alloy structural steels

The purpose of the invention is to increase the reactivity of the additive, improve the quality of steel and reduce the cost of the additive by using substandard waste.

The active chemical interaction of the components of the chip additive, as well as the reduction of time for the heating and melting operations, are provided by the increased surface of the chips (as compared to a compact material), as well as the formation of low-melting eutectic of titanium with liquid iron, the melting point of which is 1098 ° C

However, the introduction of components of the additive in the form of chips, and even more so in the form of powder, increases the waste of the additive material on the surface of the liquid metal. Therefore, the introduction of the third component, industrial oil, is very important. A thin layer of oil coating on the surface of the chip protects the chip from direct contact with liquid metal and air, thereby playing the role of a protective medium (coating). The oil on the surface of the film at the time of contact with the liquid metal burns, which leads to a consistent interaction of the deoxidizing and modifying elements of the additive with the melt and, therefore, the assimilation of the components of the additive,

In addition, the oil component enhances the reactivity of the additive by bubbling, providing more intensive mixing of the metal in the microvolumes and additional refining of the metal by removing non-metallic inclusions on the surface of the liquid metal.

The elements that make up the oil increase the modifying effect of the additive, by participating in the formation of additional crystallization centers, grinding the metal structure.

The content of oils should be not lower than 0.2% and not higher than 1.0%, since with a lower content the loss of aluminum and titanium increases, and with a higher content the content of nonmetallic inclusions in steel increases.

The metal components of the additive are non-wardrobe (not complying with the requirements of GOST or TU), waste products of the machine-building industry, namely: contaminated, mixed by high-strength alloy grades

titanium alloys and aluminum alloys. Chips that form and accumulate in large quantities are used in the construction of titanium alloys and aluminum alloys.

The introduction of titanium in the specified amount, ensures the formation of crystallization centers and obtaining a fine-grained steel structure, and

aluminum and partially titanium are metal deoxidized.

The content of aluminum chips should be not lower than 20 and not higher than 50%, since with a lower content

the melt is not deoxidized and refined with aluminum, and exceeding this limit, the modifying properties of the additive are reduced. Thus, the necessary level of modification, refinement and refining of steel is achieved only with the combined use of all three components of the additive, and the combined effect of the components improves the quality of the metal.

Examples of industrial testing of the proposed complex additive for the treatment of low-alloyed manganese steels.

To determine the effect of the additive on the properties of the steel, 7 compositions were prepared, as well as a mixture with an optimal composition of components.

Each technological additive

was prepared by mixing the components and press briquetting. Non-conforming titanium and aluminum chips were used as components.

aluminum alloys and industrial oil corresponding to GOST 2079975.

Claims (2)

The proposed additive and the known mixture were tested during the secondary treatment of 23G2Ao steel. Steel was smelted in a 150-ton converter and during casting, after introducing the ishomogenic additives and deoxidizing agent in the form of aluminum ingots, experimental samples were cast into molds weighing 10 kg. at the rate of 1 kg per 1 ton of steel. The obtained ingots were rolled on a laboratory rolling mill, heat treated, and mechanical properties were determined according to the accepted method for this steel grade. Indicators of reactivity of the addition and quality of steel grade 23G2A, treated with a complex additive, are given in the table. The experiments showed a high degree of assimilation of titanium (75 .. 85% by weight, which indicates a high reactivity of the proposed additive. The highest level of mechanical properties is satisfied Requirements TU 14-1-1258-75 and TU 14-13596-83 for 23G2A steel were obtained for steel treated with additives with the proposed content limits for its constituent components. One of the most important and difficult to achieve is ZHMB1X The quality characteristics of steel is toughness, the level of which according to specifications should be not less than 8 kgm / cm with a Brinell hardness not higher than 179 kg / mm. From the data given in the table, it is clear that the variations of the additive are 3, 4 and 5, those within the proposed composition limits have rather high indices of these characteristics (A „10.4-12.3 kgm / s HB 145-167 kg / mm) o For these compounds, a high modifying effect of the additive is characteristic. Steel treated with the indicated compositions, had a fine-grained structure corresponding to 7-8 points of austenitic grain. Low the content of nonmetallic inclusions in steel (oxides, sulfide nitrides, etc.) indicates a high radiating and deoxidizing effect of the additive. The amount of nonmetallic inclusions in steel treated with a complex additive varies in the range of 0.06-0.007%. The proposed limit, for example, 0.1 wt.% (see table, composition 1), indicates a decrease in the degree of absorption of titanium by 13%, which leads to an unacceptable decrease in the quality indicators of steel. With an increase in the oil content above the claimed 1x limit, for example 1.1 wt.% (Variant of composition 7 of the table), metal contamination with nonmetallic inclusions was observed, while the quality of the steel deteriorated due to mechanical properties, For options 2 and 6, accordingly, few deoxidizing and insufficiently modifying properties, as a result of which the quality indicators of steel in terms of the content of non-metallic inclusions and mechanical properties do not satisfy the requirements of the technical specifications for this steel. Formula from isotope 1. A complex additive for processing low-alloyed manganese steels, including aluminum and titanium-containing material, characterized in that, in order to increase the reactivity of the additive, improve the quality of steel and reduce the cost of the additive by using substandard metal waste, contains industrial oils, as aluminum - chips of aluminum alloys, and titanium-containing material - chips of titanium alloys in the following ratio of components, mas%: Ma la industrial. 0.2-1.0 Chip aluminum alloys 20,0-50,0 Chip titano49 -79,8 out alloys. 2. Additive according to PoPo, which is characterized by the fact that chips of aluminum alloys have the following 1st chemical composition, wt.%: Aluminum95.4-99.08 0.25-1.1 Magnesium 0.05-0.25 0.02 -0.35 Silicon 0.2-1.2 Iron Else Zo Additive pop.1, wherein the chips of titanium alloys have the following chemical composition, wt.%: