Abstract: To provide a heat treatment oil composition which is obtained by mixing a base oil, (A) a metallic detergent-dispersant and (B) an aliphatic carboxylic acid having from 6 to 30 carbon atoms, has high cooling capacity, and is excellent in cooling capability although the composition has a high flash point.

Abstract: Provided is a quenching method capable of producing quenched articles having little distortion and having a desired hardness. The quenching method with a coolant is specifically so controlled that the surface of the quenching bath is kept under pressure all the time throughout the step of cooling the articles being processed therein.

Abstract: The heat-treating oil composition of the present invention is characterized by comprising a mixed base oil containing a low-boiling base oil having a 5% distillation temperature of from 300 to 400° C. in an amount of not less than 5% by mass but less than 50% by mass, and a high-boiling base oil having a 5% distillation temperature of 500° C. or higher in an amount of more than 50% by mass but not more than 95% by mass. There is provided a quenching oil composition capable of exhibiting a less fluctuation in hardness or quenching distortion of a metal material treated therewith even when a large number of the metal materials are quenched therewith at the same time.

Abstract: A metal surface temperature measuring device includes: a container to contain a coolant; a measurement target; a heater to heat the measurement target; a moving mechanism for moving the measurement target; and a thermometer to measure the surface temperature of the measurement target. A main body of the measurement target is formed of silver or copper, and a surface of the main body is coated with a thin film of pure iron or an iron alloy at a thickness of 1 to 100 ?m. Further, at least the container, the heater, and the measurement target are disposed in a chamber of an inert gas atmosphere.

Abstract: A heat treatment oil composition comprising a mixed base oil containing 50-95 weight % of (A) a low viscosity base oil with kinematic viscosity of 5-60 mm2/s at 40° C., and 50-5 weight % of (B) a high viscosity base oil with kinematic viscosity of more than 300 mm2/s at 40° C. is proposed. By the use of this heat treatment oil composition for hardening of metallic material, it enables to generate little cooling unevenness, to assure the hardness of hardening processed product, and to reduce quenching distortion.

Abstract: A quenching oil for reduced pressure quenching which comprises a base oil having a kinematic viscosity at 40° C. of 40 mm2/s or more and a vapor blanket breaking agent; and a method for quenching wherein the quenching oil is used and quenching is carried out while adjusting the pressure on the surface of the oil. The method allows the achievement of cooling characteristics over a wide range from those conventionally achieved by a cold oil to those by a hot oil, by the use of a single quenching oil.

Abstract: A heat treatment oil composition comprising a mixed base oil containing 50-95 weight % of (A) a low viscosity base oil with kinematic viscosity of 5-60 mm2/s at 40° C., and 50-5 weight % of (B) a high viscosity base oil with kinematic viscosity of more than 300 mm2/s at 40° C. is proposed. By the use of this heat treatment oil composition for hardening of metallic material, it enables to generate little cooling unevenness, to assure the hardness of hardening processed product, and to reduce quenching distortion.

Abstract: Provided is a quenching method capable of producing quenched articles having little distortion and having a desired hardness. The quenching method with a coolant is specifically so controlled that the surface of the quenching bath is kept under pressure all the time throughout the step of cooling the articles being processed therein.

Abstract: Provided is a novel additive composition containing (a) a compound having, in the molecule, a group of a general formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each represent a hydrogen atom or a methyl group, but at least one of R.sup.2 and R.sup.3 is a hydrogen atom,and (b) an extreme-pressure improver containing sulfur and/or phosphorus, and optionally, as an additional component (c), an extreme-pressure improver containing neither sulfur nor phosphorus. Lubricating oil compositions comprising the additive composition have high load carrying capacity, and are effectively used as metal working oils and hydraulic oils, such as forging oil, pressing oil, drawing oil, rolling oil, cutting oil, grinding oil, etc.

Abstract: Disclosed is a refrigerator oil composition comprising at least one base oil selected from mineral oils and synthetic oils, and at least one polyether compound having a kinematic viscosity of from 200 to 10000 mm.sup.2 /sec at 100.degree. C. The composition has an excellent lubricating property, while specifically improving the lubricity of bearings. This is effective for preventing bearings from being seized and fatigued, and is suitable as a lubricating oil in refrigerators using hydrogen-containing Flon refrigerants, such as R134a, that do not cause environmental pollution.