S. Yu. Shevchenko

Criteria for evaluating the cooling capacity of quenching media

Numerous criteria have been suggested for evaluating the cooling capacity of quenching media. Although the cooling capacity of a medium can hardly be evaluated by a single number, such data can be helpful in the initial stage of choosing the medium for quenching a specific part. Various criteria for evaluating the cooling capacity of polymer quenching media have been analyzed within the developed international standard based on ISO 9950 (for industrial quenchants). Those that can be calculated from results of tests of a medium by means of a Wolfson gauge, recommended by the ISO 9950 standard, have been chosen. The aim of the present work consists in determining the correlation between the criteria suggested by various researchers for various domestic and foreign quenching liquids on a polymer base.

Quenching of ball-bearing steels and bearing parts in polymer medium UZSP-1

Results of a study of the effect of quenching in UZSP-1 quenching medium on the properties of ball-bearing steels ShKh15, ShKh15SG, ShKh20SG and data on practical use of solutions of UZSP-1 for quenching parts of bearings produced from various steels and subjected to heating for quenching by various methods are presented. Steel from commercial heats has been studied.

A Study of Quenching Cooling in Gaseous Atmospheres

Prismatic sensors of two standard sizes are used to determine the heat-transfer coefficients of high-pressure nitrogen at different turbine rotor speeds of a SECO/WARWICK 10.0VPT-4020/24N vacuum furnace. The adequacy of the values obtained is estimated.

ZAK-PG polymer quenching medium

The present work is devoted to the properties of new fireproof polymer quenching medium ZAK-PG with reversible solubility based on PG-40 polymer. The developed medium makes it possible to use various cooling regimes with various contents of the polymer in the solution. A composition in which the polymer content remains unchanged during use is suggested.

Special Features of the Carbonitriding of Parts of Instrument Bearings Designed for Extreme Service Conditions

A study is made of complexly alloyed steel 8Kh4V9F2-Sh, which is used for fabricating parts of engineering bearings operating under extreme conditions. Vacuum processes are shown to be preferable to gas carburizing for hardening the races of precision bearings. Vacuum carburizing is shown to be an effective technique for forming quality diffusion layers.

Portable Installation for Determining the Cooling Capacity of Quenching Media

The problem of replacement of quenching oils with less expensive fireproof and ecologically pure media based on polymers is important for machine building. The ecology and safety of quenching production can be improved by replacing mineral oils by new media based on aqueous solutions of salts, alkalis, acids, and polymers. Such aqueous solutions change their cooling capacity with the concentration of the solution and with the service time. For this reason, the problem of successful replacement of oils can be solved successfully if we develop methods for controlling the cooling capacity of quenching media under commercial conditions. We estimated the cooling capacity of the tested cooling media using the ISO 9950 international standard.2

A study of the cooling kinetics of bearing steel in UZSP-1 polymer quenching medium

The problem of replacing quenching oils by relatively inexpensive and fireproof media based on water is very important for machine-building plants. The present paper is a study of the possibility of using a UZSP-1 polymer quenching medium for quenching parts of roll bearings from steels of the ShKh15 type.