Title of Invention	"A QUENCHING OIL COMPOSITION USEFUL FOR HEAT TREATMENT OF STEEL"
Abstract	This invention relates to a quenching oil composition useful for heat treatment of steel which comprises- a ) 60-80% of highly refined mineral paraffinic base oil of low viscosity b) 10-20% of detergent-dispersant additive c) 5-15% viscosity index improver d) 1-5% of highly refined mineral oil base stock of high viscosity (bright stock) e) 0.5% antioxidant additive.

Full Text

This invention relates to a quenching oil composition useful for heat treatment of steel. The quenching oil of the present invention is useful for heat treatment of gas cylinder. The hardening of steel involves heating it to a critical temperature, characteristic for each steel and then cooling it rapidly (quenching) in some suitable liquid. A hardening operation consists of converting the steel into austerity by heating to high temperature and quenching to obtain hard martensite. Cooling is carried out as rapidly as possible to prevent the formation of the softer pearlite. Water and oil are the two quenching media which are most extensively used. Mineral oils are widely used as quenching media without additive for compounding (fatty) agents of any kind i.e. straight mineral oils. They are used also as the base oils in the compounded oils and additive type accelerated oils, in both of which the other constituents amount to only a few percent compounded oils incorporate fatty oils, vegetable oils or animal oils. The object of including fatty oil is to obtain a faster quench and welling of the quenching steel. The quenching oil of the present invention is prepared by using highly refined paraffinic mineral base oil of low viscosity as major component for fast quenching purposes, detergent dispersant additives for keeping deposits in suspension form. Viscosity index improver for preventing evaporation losses and high viscosity paraffinic base oil for keeping the viscosity to the required level. The quenching oil of the present invention is particularly useful for quenching of high pressure gas cylinders. The main object of the present invention is to provide composition useful as a quenching oil for hardening of steel. Another object is to provide a composition using highly refined paraffinic mineral base oil of low viscosity as main ingredient, detergent-dispersant. viscosity index improver, antioxidant as additives and high viscosity refined paraffinic base oil. All these ingredients when mixed produce a synergistic effect resulting in a quenching oil with superior quality. Accordingly, the present invention provides a quenching oil composition useful for heat treatment of steel which comprises (a) 60-80% by volume of highly refined paraffinic mineral base oil of low viscosity (b) 10-20% detergent-dispersant additive (c) 5-15% by volume viscosity index improver (d) 1-5% by volume highly refined mineral oil of high viscosity and (e) 0-5% by volume antioxidant additive. *■' Ifrr The mineral base oil used may be of viscosity in the range of 4-8 cSt at 40°C. The low viscosity mineral oil used may be selected from pale oil, neutral base oil of viscosity of viscosity 4 - 8 cSt at 40°C. The detergent-dispersant additive used may be selected from barium sulphonate, calcium sulphonate. The viscosity index improver used may be selected from polymethacryiates, polyisobutylene. The high viscosity mineral base oil used may be selected from highly refined hydrotreated base stock (bright stock), neutral 1300. The antioxidant used may be selected from zinc dialkyl dithiophophate, 2-6 di tertiary para cresol. ^ The quenching of the present invention is developed from entirely different components as that of the hietherto known composition of quenching oil. The properties of the final oil are not an aggregation of the peoperties of all the components but is a result of synergism (synergistic effect) amongst the ingredients. The oil is superior to the commercial *^ available products and harden with respect to quenching and hardness. The invention is describe in the example given below which should not be construed to limit the scope of the present invention. Example 1 v/v % a) Mineral paraffinic base oil (low viscosity) 70 b) Detergent - Dispersant (calcium sulphonate) 10 c) Viscosity Index Improver(polyisobutylene) 15 d) Mineral paraffinic base oil (high viscosity) 4 e) Antioxidant(zinc di alkyl di thio phosphate) 1 Example 2 a) Mineral paraffinic base oil (low viscosity) 75 b) Detergent - Dispersant(bariurn sulphonate) 15 c) Viscosity Index Improver(poly methacrylate) 8 d) Mineral paraffinic base oil (high viscosity) bright stock 1 e) Antioxidant(2-6 di tertary paracrysol) 1 Example 3 a) Mineral Paraffinic base oil (low viscosity) 60 b) Detergent-Dispersant(calcium sulphonate) 20 c) Viscosity Index Improver(polyisobutylene 1 o d) Mineral paraffinic base oil (high viscosity) 5 e) Antioxidant(zinc di alkyl di thio phosphate) 5 The quenching oil prepared by present invention meets the Indian Standard IS-2664-1980 and are comparable to a commercial oil as shown in Tables 1 and 2. TABLE 1 (Table Removed) TABLE -2 HARDNESS OF TEST SPECIMENS (COMPLETELY IMMERSED) SAMPLE AVERAGE HARDNESS (Re) (Table Removed) The inferences drawn from the above are: 1. The quenching time of the developed product is least in or test as well as with the General Motors(G.M.)quenchometer. 2. The average hardness obtained with the developed product is maximum. The advantages of the present invention are: The commercial products available in the market are unable to meet the requirement of heat treatment of gas cylinders. The developed quenching oil has following advantages. 1. It is based on indigenous and easily available raw material. 2. The developed quenching oils composition is quite comparable with available oil with respect to the cooling and hardness of the gas cylinders. 3. The developed product will conserve foreign exchange. Claim A quenching oil composition useful for heat treatment of steel which comprises a) 60-80% of highly refined mineral paraffinic base oil of low viscosity b) 10-20% of detergent-dispersant additive c) 5-15 % viscosity index improver d) l-5% of highly refined mineral oil base stock of high viscosity (bright stock) e) 0-5% antioxidant additive A composition as claimed in claim 1, wherein the mineral paraffinic base oil used has a viscosity in the range of 4-8 cSt at 40°C A composition as claimed in 1&2 wherein the low viscosity mineral base oil used is selected from neutral base stock of viscosity 4 - 8 cSt at 40°C. A composition as claimed in claim 1 to 3 wherein the detergent-dispersant additive is selected from calcium sulphonate, barium sulphonate. A composition as claimed in claims 1 to 4 wherein the viscosity index improver used is selected from poly-isobutylene, poly methacrylate. A composition as claimed in claims 1 to 5 wherein the high viscosity refined paraffinic base oil used has a viscosity in the range of 30-40 cSt. A composition as claimed in claim 1 to 6 wherein the antioxidant is zinc dialkyl di- thiophosphate, 2-6 di tertiary para cresol. A quenching oil composition useful for heat treatment of steel substantially as herein described with reference to the examples.

Documents:

602-DEL-1995-Abstract.pdf

602-DEL-1995-Claims.pdf

602-del-1995-correspondence-others.pdf

602-del-1995-correspondence-po.pdf

602-DEL-1995-Description (Complete).pdf

602-del-1995-form-1.pdf

602-del-1995-form-2.pdf

602-del-1995-form-4.pdf

602-del-1995-form-9.pdf