SU1407968A1 - Hardening medium - Google Patents

Abstract

The invention relates to the field of metallurgy, and more specifically to quenching means used in the heat treatment of steels. The aim of the invention is to improve the efficiency and effectiveness of the quenching medium. The quenching medium contains, in May.%: Sodium salt of carboxyl methylcellulose O, 2-2.5; soda ash 0.5-2.0 and water. The proposed environment allows quenching to the required hardness without cracking, reducing the consumption of Na-CMC, eliminating corrosion on parts and hardening equipment, increasing hardenability and hardening of products from complex steel grades. 3 tab ..g

Description

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The invention relates to metallurgy, and more specifically to quenching media used in the heat treatment of steels.

The purpose of the invention is to increase the efficiency and effectiveness of the quenching medium.

The quenching medium contains sodium carboxymethyl cellulose, soda ash and water.

PRI im p Standard parts of forge-and-press machines of various configurations of the following steel grades are subjected to quenching: 40Х, 45Х, АХХ, 40Х2МА, 9ХС, 111Х15, 38Х2МЮА, Х8ХЮ, 65Г, А5,60С2, 20Х, 18 ХГТ.

The optimum concentrations and cooling properties of the quenching medium are determined by the hardness of the steels after quenching, by the cooling curves on the graph — temperature — time, by the cooling rate in different temperature ranges (pearlite and martensite) and by cracking. Hardness corresponds to the specifications of the drawing details. Thermally processed about 200 staff units.

Table 1 presents the proposed and well-known compositions of the quenching medium with different concentrations of components in an aqueous solution,

Table 2 shows the dependence of the hardness of hardened products on the concentration of components and the working temperature of the medium.

Table 3 shows the comparative cost of the proposed and known environment.

From table 2 and 3 it follows that after quenching in the environment of the proposed composition of the cracks in the heat-treated products x not detected. The medium is slightly sensitive to changes in its temperature during the quenching process and provides three

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The buoyant hardness of products in the range of working temperatures of 20-60 C. With an increase in the concentration of Na-CMC in the solution (more than 2.5 wt.%), the average cooling rates at the pearlite and martensitic transformations and the amplitude of their fluctuations decrease so much that it leads to a decrease hardness of the instilled products. Therefore, an increase in the concentration of Na-CMC (more than 2.5 wt.%) Is undesirable. The added medium does not cause corrosion on the hardened products and the walls of the quenching bath, i.e. anti-corrosion.

The cost of additives in the proposed environment of soda ash (Na CO) is almost two times less than the cost of additives in a known medium (in addition to Na-CMC).

The proposed environment is more economical in operation both by reducing the consumption of the main component of Na-CMC and by eliminating the formation of corrosion on hardened products and quenching equipment and the associated unproductive material costs associated with it. In addition, the medium is more efficient, hardenability and hardenability of products from complex alloyed steel grades and does not cause cracks in them.

Claims (1)

Invention Formula Quenching medium containing water and sodium carboxymethylcellulose, characterized in that, in order to increase its efficiency and economy, it additionally contains soda ash in the following ratio, wt.%: Sodium salt of carboxymethylcellulose 0.2-2.5 Soda calcinate 0.5-2.0 Water the rest. Table 1 0.2 0, 5 0.5 1.0 1.5 1.8 2.0 0.5 1.0 1.0 1.2 1.5 Rest Os-Os-Os-Os-0-o-taltal-znatalnaya 2.0 2.5 2.5 0.50 2.0 1.5 Rest 1.0 Rest ABOUT Continued table. 2 rinzT 40XH2MA 7 7 7 7 7 7 7 9 Wednesday, wt.% 14079688 Continuation of table 2 56 64 66 63 62 64 59 62 || eleven | T Spreadsheets - -----. 3 Cost of the component, RUB