SU1616768A1 - Method of continuous casting of alloyed grades of steel - Google Patents

Abstract

This invention relates to metallurgy, in particular to the continuous casting of ingots of alloyed steel grades. The goal is to increase the yield by adjusting the carbon content of the steel. The method involves the supply of metal in the mold and the supply to the meniscus protective lubricating mixture containing, wt.%: Slag-forming components 10-40, powdered graphite 1-60 and pyrocarbon 1-60. The composition of the mixture applied to the meniscus varies depending on the carbon content in the steel, which is determined during casting, increasing the graphite content and reducing the pyrocarbon content with the carbon content in the steel below the lower limit to the required carbon content and decreasing the graphite content and increasing the pyrocarbon content with carbon content in steel at the upper limit.

Description

The invention relates to metallurgy, in particular, to continuous casting of ingots, mainly from alloyed steel grades.

The purpose of the invention is to increase the yield by adjusting the carbon content of the steel.

The method for 38KhNSMFA steel with a carbon content of 0.365% and a cross section of 270 X 370 mm is carried out as follows.

The metal is supplied to the molds from the ladle through a non-stop filling device with overflow thresholds below the metal meniscus level. The ingot extrusion speed is 0.4 m / min. The temperature of the metal in the ladle after the release of the furnace 1600-1630 ° C. The carbon content in steel according to GOST 4543-71 is 0.33-0.40%. The protection of the metal mirror in the crystallizer is carried out by the mixture containing the component in amounts determined by the carbon content of the cast steel. According to the obtained carbon content in steel, the content of graphite and pyrocarbon in the mixture fed to the meniscus is adjusted. Samples are cut from the ingot during the casting process to determine the carbon content and, if necessary, increase and decrease the graphite content in the mixture during casting.

The table shows the carbon content in steel and the composition of the mixture used in this case according to examples 1-17.

As can be seen from the examples, the application of the method with the carbon content in the steel below the lower limit and with the carbon content in the steel at the upper limit makes it possible to obtain the content of ug

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Lerod ingots within the brand condition either due to additional carburization or lack of it, which makes it possible to eliminate the ingestion of ingots by chemical analysis (carbon), thus increasing the yield.

Claims (1)

Formula of the Invention The method of continuous casting of alloyed steel grades, including a subtype of metal into the mold and feeding a meniscus protective lubricant mixture of the composition, wt.%; slag-forming components 10-40, powdered graphite and pyrocarbon 1-60, characterized in that in order to increase the yield by adjusting the carbon content in the steel, the carbon content in the steel is determined during the casting process and the content of graphite and pyrocarbon in the mixture is changed limits, while the carbon content in the steel is below the limit for every 0.01% of carbon in the mixture is not less than 15% graphite, and if the carbon content in the steel is higher than its average value, for every 0.01% carbon in the steel, at least 15% pyrocarbon is introduced into the mixture.