US2529189A

US2529189A - Lubricating metal surfaces during cold working

Info

Publication number: US2529189A
Application number: US19646A
Authority: US
Inventors: Albert G Rocchini; Richard J Neely
Original assignee: Gulf Research and Development Co
Current assignee: Gulf Research and Development Co
Priority date: 1948-04-07
Filing date: 1948-04-07
Publication date: 1950-11-07
Anticipated expiration: 1967-11-07

Description

in contact with the metal.

Patented Nov. 7, 1950 LUBRICATING METAL SURFACES DURING COLD WORKING Albert G. Rocchini, ,Springdale, and Richard J.

Neely, Oakmont, Pa., assignors to Gulf Research & Development Company, Pittsburgh Pa., a corporation of Delaware No Drawing. Application April 7, 1948,

Serial No. 19,646

8 Claims.

1 This invention relates to lubricating metal surfaces during cold working; and it comprises, in cold working a metal subsequently to beannealed, a process improvement which resides in lubricating the surfaces of said metal by means of a lubricant comprising a petroleum lubricating oil containing a small amount of an aniline derivative represented by the structural formula:

RIITH wherein R is a substituent selected from the class consisting of a benzyl group and hydrogen and R is selected from the class consisting of methoxy and ethoxy groups; all as more fully hereinafter set forth and as claimed.

The cold working of metals, such as the cold rolling, drawing, or stamping of aluminum, stainless steel, Monel metal, and the like, is ordinarily followed by an annealing process. Annealing is often performed in a gas-fired furnace wherein the products of combustion come Owing perhaps to the restricted space adjacent the bulk of the metalsurfaces, and furthermore to the fact that conditions in the furnace are not conducive to good combustion, it has been found that considerable staining of the metal has reoxide, may appear in different positions on the strip and is believed to be caused by foreign mattersuch as dirt adhering; to the surface and being carried on the strip into the annealing furnace. The third type of stain which may appear in streaks or spots is believed to be a carbon formation resulting when the working lubricant is subjected to the reducing atmosphere in the annealing furnace. It is the formation of the latter type of stain which the method of this invention inhibits or substantially retards.

In the past, the elimination of the stain resulting from the lubricant has been accomplished by one of several alternatives. In one embodiment, the oil stain has been eliminated by. removingthe lubricating oil from the cold-Worked metal with a solvent prior to the annealing step. Other embodiments have included chemically or mechanically removing the stain afterthe annealing operation. These embodiments, however, introduce expensive processing steps.

The type of lubricant employed in cold working processes has also been the subject of many prior investigations. Among the lubricants which have been used are included animal oils, vegetable oils, minerals oils, and mixtures of these and water-oil emulsions. Animal and vegetable oils are effective lubricants but they have certain disadvantages in that they are rather expensive, are not good coolants, and are easily oxidized with the resultant development of rancidity. Furthermore, animal and vegetable oils, having high carbon residue values, have been unsatisfactory in that unlessthey. are removed from the worked metal prior to its being annealed, they will leave stains in the form; of carbon deposits onthe metal when. it is subsequently annealed. 'While straight mineral oils are satisfactory with respect to theircost, cooling properties, and stability,'they, as do the animal and vegetable oils, also have a disadvantage in that unless they are removed from the worked metal prior to its being annealed, they Will leave a stain on the surface of the annealed metal. Water-oil emulsions are advantageous in that they may easily be removed from metal surfaces by washing with water prior toannealing, but this step in itself 'complicates'the working process. Water-oil emulsions have a further disadvantage in that with repeated use as c.01d

'working lubricants, the Water tends to evaporate from the"water-oil emulsions thereby changing the ratio of water to oil. Since the ratio of water to' oil should be kept as uniform as possible to obtain optimum results, frequent analysis of the lubricant is required thereby adding complexity to the process.

. It is the primary object achieved by this invention tov provide a method of lubricating metal surfaces during cold Working. by means of a lubricant which if allowed to remain on the metal during a subsequent annealing operation 3. cant comprising a petroleum lubricating oil which would normally tend to stain said metal surfaces during annealing thereof anda small amount, sufficient to inhibit or substantially retard the formation of strain on the metal when it is subsequently annealed, ofan aniline derivativerepresented by the structural formula RNH dine, N-benzyl-para-anisidine, ortho-phenetidine, para-phenetidine, N-benzyl-ortho-phenetidine, N-benzyl-para-phenetidine, and the like.

'These compounds are advantageously added to a petroleum'lubricating oil of the roll oil and -draw oil type in an amount between about 1 (94% aluminum, 4.0% copper, 0.5% manganese and 0.5% magnesium). 1

In the practice of our invention any suitable lubricating oil base, whether it is derived from a parafiinic, naphthenic, or mixed base crude, may be employed. Although it is seldom necessary in compositions of the type disclosed herein, the lubricating oil base may contain one or more of the so-called additive agents, including oiliness and extreme pressure agents, viscosity index improvers, pour point depressants,

fietergents, foam inhibitors, and corrosion and oxidation inhibitors. The particular lubricant chosen depends on the type of cold-working op- =eration for which it is intended. For example,

oils used in cold rolling are generally highly refined and are relatively volatile having viscosities between about 50 and 200 SUV at 100-F., whereas oils used in drawing operations may have viscosities as high as 5000 SUV at 100 F. It is not intended to limit this invention with respect to the particular lubricating oil base.

The advantages to be obtained in accordance with our invention are illustrated in the following comparative laboratory tests made ona highly refined naphthenic base oil having a Saybolt Universal Viscosity of 53 at'100 F. and the same oil containing compounds of the type disclosedherein. To simulate actual operating conditions of the annealing of cold-rolled aluminum, 1 ml. of the oil to be tested was placed between two aluminum plates (99.2% aluminum). The aluminum plates were then placed in a, mufiie furnace for 30 minutes at a temperature of 650 F., this being the tem'perature of the metal as determined by a thermocouple. The plates were then removed andinspected. The appearance 3 4 r the aluminum after annealing, as tabulated hereinbelow, was determined by visual inspection and comparison with a blank set of plates.

Compound Incorporated in a Highly Per Cent Appearance of Refined Naphthem'c Base Oil (53 by Aluminum after SUV at 100 F.) Weight Annealing Severe Stain. Slight Stain. Do. No Stain. Slight Stain.

Do. Do. No Stain.

Do. Do.

While the above compositions have been tested on cold-rolled aluminum plates, the method of our invention is advantageous when applied to any metal being cold worked, and subsequently to be annealed. For instance, the method of our invention is applicable to the cold working of non-ferrous metals other than aluminum, such for example, as magnesium or Monel metal, and is also satisfactory for the cold rolling of stainless steel, particularly when such metals are to be annealed after cold working, and where it is desirable that the surfaces of such metals be clean and bright after annealing. The method of our invention obviatesthe expensive step of removing the oil film from the metal prior to its being annealed, and at the same time overcomes the staining which normally would occur in the annealing operation when employing a straight mineral lubricating oil as a lubricant for the cold working of metals.

While our invention has been described herein with particular reference to certain specific embodiments thereof by way of illustration, it is to be understood that the invention is not limited to such embodiments except as hereinafter defined in the appended claims.

,an aniline derivative represented by the struc tural formula:

.RNH

wherein R is a substituent selected from the class consisting of a benz'yl group and hydrogen and R is selected from the class consisting of methoxy and ethoxy groups, and, without removing the film of lubricant from the surfaces of the cold-worked metal, annealing aid .coldworked metal.

2. A metal finishing process which comprises cold Working a metal while'maintaining on the surf-aces of said metal a film of lubricant consisting essentially of a petroleum lubricating oil which would normally tend to stain said metal surfaces during the annealing thereof and between about 1.0 and 10.0 per cent by weight of an aniline derivative represented by the structural formula:

ITIH:

wherein R is selected from the class consisting of methoxy and ethoXy groups, and, without removing the film of lubricant from the surfaces of the cold-worked metal, annealing said coldworked metal.

3. An aluminum finishing process which comprises cold rolling aluminum while maintaining on the surfaces of said aluminum a film of lubricant consisting essentially of a highly refined relatively volatile petroleum lubricating oil which would normally tend to stain said aluminum surfaces during the annealingthereof and between about 1.0 and 10.0 per cent by weight of o-anisidine, and, without removing the film of lubricant from the surfaces of the cold-rolled aluminum, annealing said cold-rolled aluminum.

4. An aluminum finishing process which comprises cold rolling aluminum while maintaining on the surfaces of said aluminum a film of lubricant consisting essentially of a highly refined relatively volatile petroleum lubricating oil which would normally tend to stain said aluminum surfaces during the annealing thereof and between about 1.0 and 10.0 per cent by weight of p-phenetidine, and, without removing the film of lubricant from the surfaces of the cold-rolled aluminum, annealin said cold-rolled aluminum.

5. A metal finishing process which comprises cold working a metal while maintaining on the surfaces of said metal a film'of lubricant consisting essentially of a petroleum lubricating oil which would normally tend to stain said metal surfaces during the annealing thereof and between about 1.0 and 10.0 per cent by weight of an aniline derivative represented by the structural formula:

of methoXy and ethoxy groups, and, without removing the film of lubricant from the surfaces of the cold-worked metal, annealing said coldworked metal.

6. An aluminum finishing process which comprises cold rolling aluminum while maintaining on the surfaces of said aluminum a film of lubricant consisting essentially of a highly refined relatively volatile petroleum lubricating oil which would normally tend to stain said aluminum surfaces during the annealing thereof and between about 1.0 and 10.0 per cent by weight of N-benzyl-o-anisidine, and, without removing the film of lubricant from the surfaces of the coldrolled aluminum, annealing said cold-rolled aluminum.

7. An aluminum finishing process which comprises cold rolling aluminum While maintaining on the surfaces of said aluminum a film of lubricant consisting essentially of a highly refined relatively volatile petroleum lubricating oil which would normally tend to stain said aluminum surfaces during the annealing thereof and between about 1.0 and 10.0 per cent by weight of N -benzylo-phenetidine, and, without removing the film of lubricant from the surfaces of the cold-rolled aluminum, annealing said cold-rolled aluminum.

8. An aluminum finishing process which comprises cold rolling aluminum while maintaining on the surfaces of said aluminum a film of lubricant consisting essentially of a highly refined relatively volatile petroleum lubricating oil which would normally tend to stain said aluminum surfaces during the annealing thereof and between about 1.0 and 10.0 per cent by weight of N-benzylp-phenetidine, and, without removing the film of lubricant from the surfaces of the colol-rol1ecl aluminum, annealing said cold-rolled aluminum.

ALBERT G. ROCCHINI. RICHARD J. NEELY.

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

UNITED STATES PATENTS Number Name 7 Date 2,257,869 Trautman Oct. 7, 1941 2,258,930 Haefner Oct. 14, 1941 2,308,690 Hughes Jan. 19, 1943 2,391,631 Kingerley Dec. 25, 1945 2,403,238 Rosenstiehl July 2, 1946 2,430,400 Hoelscher Nov. 4, 1947

Claims

1. A METAL FINISHING PROCESS WHICH COMPRISES COLD WORKING A METAL WHILE MAINTAINING ON THE SURFACES OF SAID METAL A FILM OF LUBRICANT CONSISTING ESSENTIALLY OF A PETROLEUM LUBRICATING OIL WHICH WOULD NORMALLY TEND TO STAIN SAID METAL SURFACES DURING THE ANNEALING THEREOF AND BETWEEN ABOUT 1.0 AND 10.0 PER CENT BY WEIGHT OF AN ANILINE DERIVATIVE REPRESENTED BY THE STRUTURAL FORMULA: