US2617769A

US2617769A - Rolling oil composition

Info

Publication number: US2617769A
Application number: US30734A
Authority: US
Inventors: Jr Clayton W Nichols; Eldon L Armstrong; Harold J Schroeder
Original assignee: Socony Vacuum Oil Co Inc
Current assignee: ExxonMobil Oil Corp
Priority date: 1948-06-02
Filing date: 1948-06-02
Publication date: 1952-11-11
Anticipated expiration: 1969-11-11

Description

Patented Nov. 11, 1952 ROLLING OIL COMPOSITION Clayton W. Nichols, Jr., Mineola, Eldon L. Armstrong, Garden City, and Harold J. Schroeder, Brooklyn, N. Y., assignors to Socony-Vacuum Oil Company, Incorporateda corporation of New York No Drawing. Application :Iune .2, "1948, Serial No. 30,734

6 Claims.

The present invention relates to an improved process for rolling non-ferrous metals and, more particularly, to the elimination or reduction in pick-up in hot-rolling relatively soft aluminum alloys and pure aluminum and the elimination or reduction of staining in the rolling of copper alloys, especially brass, through the use of a novel soluble oil lubricant.

The present invention relates to an improved process for rolling non-ferrous metals whereby metalsurfaces free of stains and pits are obtained.

In prior art rolling operations on non-ferrous metals, both soluble and non-soluble roll oils have been used. Non-soluble oils, to which group the straight mineral oils and compounded mineral oils belong, were satisfactory from the standpoint of providing the necessary lubrication but were deficient in cooling capacity. The lack of cooling capacity is an inherent deficiency of hydrocarbons and fatty oils. It can be assumed for purposes of fairly accurate approximation that the cooling capacity of hydrocarbons and fatty acid glycerides (fatty oils) is about one-half that .of water because the cooling capacity of a cooling medium is a direct function of the specific heat of that cooling medium.

Many attempts have been made in the past to use oil emulsions in order to take advantage of the lubricating value of their oil content and the cooling value of the water content. Insofar as applicants have been able to discover, no soluble oil formulation has been offered to the nonferrous metal industry which has satisfied all of the requirements of rolling mills processing nonferrous metals. The primary deficiency of the soluble-oil emulsions which have been tried has been the adverse effect of the emulsions on the rolled metal surfaces. For example, brass when rolled with prior art soluble-oil emulsions containing soap type emulsifiers, such as sodium or potassium fatty acid soaps, had unsightly stained surfaces.

In hot rolling aluminum, another deficiency of the prior art soluble-oil emulsions was recogniz'ed, to wit: the so-called pick-up. The latter phenomenon is the appearance of nodules or accretions on the surfaces of the rolls. The accretions build up and form minute hills which in turn produce peak um't loads on the new portions of the metal being rolled and the deformation snowballs to a point when the mill must be shut-down and the rolls reground. In addition to considerable loss of time and its monetary value, there is an appreciable spoilage of semi-finished metal.

In the early stages of formation the aforesaid accretions can be removed from the surfaces of 2 the rolls rather easily. 0n the other hand, when through carelessness or oversight the pick-up is allowed to remain on the rolls for any appreciable length of time, it is extremely diificult to remove the pick-up without resorting to a-cutting operation. 1

Although several assumptions have been made concerning the composition of the nodules of pick-up, it has recently been discovered that the material consists primarily of aluminum fines with not more than traces of aluminum oxide, hydroxide, salts and soaps. The use of soluble-oil emulsions containing sodium and/or potassium soaps or sulfonated materials, i. e., conventional type soluble-oil emulsions showed no marked tendency to prevent the build-up of aluminum particles on work rolls during the hot rolling of aluminum. An experimental solubleoil emulsion .gontaining triethanolamine soap emulsifiers showed some improvement over the conventional soluble-oil emulsions but was not outstanding in this respect. Emulsions of the conventional soluble-oil type having pH values above :10 showed some improvement over similar type emulsions having lower pH values. However, generally, there appeared to be no simple solution to this problem. Thus, it became necessary to attempt .to correlate pick-up and the lubricating properties of the soluble-oil emulsions.

Various test machines were used in an attempt to ShQW some correlation between lubricating properties of soluble-oil emulsions and pick-up tendencies.- Samples of fresh emulsions and of emulsions which apparently had reached the end of useful life, in respect to pick-up in the rolling mill, were used in this test work but, in all cases, no data showing a significant correlation were obtained. Falex tests were made for use as a means of estimating probable wear characteristics and the 4-Ball machine (described in Army-Navy specifications under the code number ,AN-G-IO) was employed to determine the coefficients of friction between steel and aluminum in the presence of the various emulsions. However, no correlation between these properties and pick-up tendency was readily apparent. These negative results lead to the development of a test wherein pick-up could be produced at will.

In an attempt to reproduce the actual 'pickup, a Modified 'Timken Test was developed which. it was hoped, would be helpful in reproducing pick-up. The usual assembly of this equipment was employed with the exception that an aluminum block of soft 28 metal was substituted for the conventional steel Timken blocks. (28 grade aluminum is the term used by the -industry and in government specifications to designate commercially-pure metal containing over 99 per cent pure aluminum. The small amount of impurities is chiefly iron and silicon.) The hardened steel Timken ring was used and the solubleoil emulsion circulated in the usual manner for this test equipment. The ring was rotated at a speed of 400 R. P. M. and a lever arm load of 5 pounds was applied. The duration of the test was one-half hour.

At the completion of the runs with conventional soluble-oil emulsions, it was observed that a greyish tacky deposit covered the steel Timken ring. This material was removed readily by wiping, but on standing it became hard and brittle. This close similarity in properties of the experimental deposit and the cause of the industrial problem lead to intensive examination of both products. This examination, which involved the use of both spectrographic and X-ray difiraction techniques, showed that solid constituent was metallic aluminum. Both the experimental deposit and the industrial deposit were the same and consequently the method for experimentally producing the deposit satisfactorily simulated actual performance characteristics. Therefore, a measure which in the experimental procedure eliminated or markedly reduced the amount of pickup would be effective in actual industrial operations.

All tests carried on samples of used emulsions by the Modified Timken procedure described hereinbefore indicated that regardless of length of service or concentration, pick-up would occur.

In view of the wide variety of products tested it was manifest that numerous factors which might affect pick-up were investigated. The elimination of such materials as rosin'and petroleum sulfonates was found not to improve pick-up characteristics. The addition of various inorganic salts, organic esters, and metalloorganic compounds provided no complete solution of the problem. Comparison of two soluble-oil emulsions whose anti-wear properties are not comparable established that that characteristic is not the controlling factor.

Further investigation showed that when the soluble-oil emulsion was so constituted that the aluminum was either in solution as a soluble salt or as a dispersed phase of a stable emulsion the tendency to pick-up was reduced or eliminated. One means whereby the aluminum could be brought into solution was the use of an emulsion having a pH of or higher. However, this solution of the problem is not a satisfactory one since it would be difficult to maintain the pH of a circulating emulsion at or above pH 10.5 in actual industrial operation.

It was found, however, that an emulsion of soluble-oil in which the emulsifier is of the nonionic type gave satisfactory results. In such an emulsion the particles of metallic aluminum may remain suspended for several weeks.

Further investigation of the problem of producing rolled copper or brass free from stains or substantially so revealed the fact that although there would appear to be no connection between aluminum pick-up and the staining of brass during cold-rolling nevertheless the use of emulsions of soluble-oil in which the emulsifier is of the non-ionic type solved the problem of coldrolling copper and brass substantially free from stain. s I

. Accordingly, it is an object of the present in- 4 vention to provide an improved method for rolling non-ferrous metals in which a soluble-oil emulsion containing a non-ionic emulsifier is used. It is also an object of the present invention to provide a soluble oil containing a non-ionic emulsifier and suitable for dilution with water to provide a roll emulsion capable of holding small particles of aluminum in suspension for several weeks.

metals is well-known to those skilled in the art.

In general, rolling involves passing a billet of the metal through the bit of two rolls a sufiicient number of times to reduce the billet to a sheet of the desired thickness, 1. e., gauge. The amount of reduction in each pass is dependent upon several factors including composition of the metal being rolled, the temperature of rolling, need for intermediate annealing and the like. However, during the rolling operation, whether it be a socalled cold-rolling or a hot-rolling, it is necessary to cool and lubricate the working roll or rolls by means of a coolant-lubricant. The coolant-lubricant is usually applied to the working roll as a plurality of streams of liquid in sufficient total quantity to keep the workin roll from softening and to keep the friction between the working roll and the metal being rolled to a minimum. In keeping with the spirit of the present invention the coolant-lubricant is an emulsion of oil-in-water prepared from either fatty oil, i. e., glycerides of fatty acids such as lard oil and others well-known to those skilled in the art, or hydrocarbon oils, such as mineral oils of suitable viscosity, say seconds Saybolt at 100 F. or a combination of fatty and hydrocarbon oils using a non-ionic type emulsifier.

The non-ionic type of emulsifiers are distinctive in that they may be used over -a rather wide pH range and include such materials as glycerol oleate, polyglycerol oleate and other similar esters of the long chain aliphatic carboxylic acids, proteins and polyoxyalkylene derivatives of hexitol anhydride partial esters of long chain aliphatic carboxylic acids. Of the non-ionic type emulsifiers the polyoxyalkylene derivatives of the hexitol anhydride partial esters are preferred.

In addition to the fatty or hydrocarbon oil and emulsifier it is desirable, and in fact preferred, to use a coupling agent such as butyl Carbitol, 2- ethylhexanediol-l,3 or the like.

Illustrative of the novel soluble-oils is the composition A which has been used in the rolling of aluminum and composition B which has been used in the rolling of brass and other copper alloys. It is to be understood that the use of composition A is not limited to the rolling of aluminum alloys nor is the use of composition B limited to the rolling of brass or copper alloys. Either composition and analogous compositions may be used for rolling either aluminum or copper alloys.

Soluble oil 'In general, the composition of the novel soluble-oils will be within the ranges set forth hereinafter.

Soluble oil Component: Percent by weight 'Glyceride oil or fatty oil to 40' Non-ionic emulsifier 0.5 to 15.0 Coupling agent 0.1 to 5.0 Water 0.1 to 3.0

Mineral oil (lubricating grade) Balance The soluble-oils having the composition set forth hereinbefore may be diluted with water in the proportion of 1 part of oil to 1 to 20 parts of water and satisfactory roll emulsions obtained.

We claim:

1. A soluble-oil base consisting of an oleaginous lubricant as a major constituent, a minor proportion, from about 0.1 weight per cent to about 3.0 weight per cent, of Water and an amount, from about 0.5 weight per cent to about 15.0 weight per cent, of a, non-ionic emulsifier efiective to provide a stable emulsion.

2. A soluble-oil base consisting of a fatty oil, 0 to about 40 weight per cent; a non-ionic emulsifier, about 0.5 to about 15 weight per cent; water, 0.1 to about 3 Weight per cent and the balance mineral oil of Saybolt Universal viscosity at 100 F. of about 100 seconds.

3. A soluble-oil base as described and set forth in claim 2 in which about 0.1 to about 5 weight per cent of a coupling agent is included.

4. A soluble oil base consisting essentially of about 0 to about 5 weight per cent of lard oil, about 8.5 to about 9.5 weight per cent polyoxyalkylene derivative of hexitol anhydride partial ester, about 0.5 weight per cent 2-ethy1hexanediol-l,3, about 2 weight per cent water and the balance parafiin oil having a Saybolt Universal viscosity at 100 F. of about 100 seconds.

.5. A soluble-oil base consisting essentially of about 0 to about 40' weight per cent of a glyceride oil, up to about 99 weight per cent mineral lubricating oil, a minor proportion from about 0.1 weight per cent to about 3.0 weight per cent, of water, and an amount, from about 0.5 weight per cent to about 15.0 weight per cent, of polyoxyalkylene derivative of hexitol anhydride partial ester efiective to provide a stable emulsion.

6. A soluble-oil base consisting essentially of an oleaginous lubricant as a major constituent, said oleaginous lubricant being selected from the group consisting of mineral lubricating oil and a mixture of mineral lubricating oil and glyceride oil, a minor proportion, from about 0.1 Weight per cent to about 3.0 weight per cent, of water, and an amount, from about 0.5 weight per cent to about 15.0 Weight per cent, of a non-ionic emulsifier effective to provide a stable emulsion.

CLAYTON W. NICHOLS, JR. ELDON L. ARMSTRONG. HAROLD J. SCI-IROEDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,965,935 Blount et al July 10, 1934 1,973,684 Lorig Sept. 11, 1934 2,258,552 Harris Oct. 7, 1941 2,303,142 Spangler Nov. 24, 1942 2,342,199 Hurtt Feb. 22, 1944 2,382,398 Cordero Aug. 14, 1945 2,387,157 Koppenhoefer Oct. 16, 1945 2,404,240 MaoLaurin July 16, 1946 2,420,329 Shipp et al. May 13, 1947 2,470,405 Leland May 17, 1949 2,470,913 Bjorksten et a1 May 24, 1949

Claims

1. A SOLUBLE-OIL BASE CONSISTING OF AN OLEAGINOUS LUBRICANT AS A MAJOR CONSTITUENT, A MINOR PROPORTION, FROM ABOUT 0.1 WEIGHT PER CENT TO ABOUT 3.0 WEIGHT PER CENT, OF WATER AND AN AMOUNT, FROM ABOUT 0.5 WEIGHT PER CENT TO ABOUT 15.0 WEIGHT PER CENT, OF A NON-IONIC EMULSIFIER EFFECTIVE TO PROVIDE A STABLE EMULSION.