US3318126A - Method of rolling steel strip material - Google Patents

Description

May 9, 1967 J. H. WERTHMAN 3,318,126

METHOD OF ROLLING STEEL STRIP MATERIAL Filed April 3, 1964 m 20 PIIS: 1

4 v Timer INVENTOI? JOHN H, WERTHMA/V AWor ey .maXimum elongation in a United States Patent Ofifice 3,318,125 Patented May 9, 1967 3,318,126 METHOD OF ROLLING STEEL STRIP MATERIAL John H. Werthrnan, Leechburg, Pa., assignor to Allegheny Ludlum Steel Corporation, Brackenridge, Pa., a corporation of Pennsylvania Filed Apr. 3, 1964, Ser. No. 357,148 12 Claims. (Cl. 72-39) This invention relates to cold rolling of strip steel, and more particularly to planish or temper rolling of steel strip material having surface finishes.

The final rolling operation in the production of many grades of steel is a temper or planish roll. This temper rolling is for the purpose of cold working the material to the proper hardness and strength, and also, in the case of certain types of steel such as the ferritic grades of stainless steel, serves the additional purpose of preventing the appearance of Liiders lines or stretcher strains when the material is later cold worked. To prevent the formation of stretcher strains or Liiders lines in ferritic stainless steel, it is necessary to cold work the material in this temper rolling enough to provide an elongation of at least about /8" in three feet of material or the cold work is insufficient for this purpose. Since the rolls used for temper rolling are rather large in diameter, it is sometimes diificult to obtain the desired elongation in a single pass, or even in two or three passes, especially in the case of rather thin material of the order of magnitude of .008" to .012". It is well known that greater elongation can be obtained if wet rolling lubricants such as palm oil or soluble oils are used, but these lubricants will mark the surface of the steel being rolled, detracting from its bright ness and appearance, and hence it is common practice to avoid the use of these rolling lubricants during temper rolling of bright surfaced material and to do the rolling dry (i.e., free of lubricants).

Also, when several passes are used to obtain the required elongation, it sometimes becomes a problem to maintain the strip completely fiat across its width, thus necessitating at least one or tWo additional flattening passes, all of which greatly increases the cost of finishing the strip.

It is therefore a principal object of this invention to provide a method of temper rolling steel to provide the minimum number of passes without damaging or marking the surface.

It is a further object of this invention to provide a method of temper rolling steel strip material, which rolling provides the elongation characteristics of rolling with a wet lubricant, yet which does not mark or damage the surface of the steel.

Still a further, more particular object of this invention is the provision of a method of rolling bright surfaced steel strip material utilizing a film formed by the drying of a volatile substance, which film enhances the elongation characteristics of the rolling without detrimentally marking the surface of the material.

Still an additional object of this invention is the provision of a method of rolling bright surfaced steel strip material wherein a volatile substance is sprayed on the rolls or on the material being rolled, and is allowed to evaporate, leaving only a thin, invisible, adherent film when the material enters the bite of the rolls.

These and other objects, together with a fuller understanding of the invention, will become apparent from the following description, when taken in conjunction with the accompanying drawing in which:

FIGURE 1 is a schematic view of a temper rolling mill with the spraying apparatus shown installed on the lower roll;

FlG. 2 is an enlarged view of the spraying apparatus, and i FIG. 3 is a view taken substantially along the line III-III of FIG. 2.

Referring now to the drawing, and in particular to FIG. 1, a two-high temper mill is shown and designated generally as 10. The rolling mill 10 is provided with an upper roll 12 and a lower roll 14 between which the material to be rolled, designated as M, is passed. In conventional temper rolling practice, these rolls 12 and 14 are maintained dry and free of any rolling lubricant in order to avoid marking the surface of the strip as it is rolled. Any visible liquid which is on the surface of the material M as it enters the rolls, or which is on the rolls 12 or 14 at the bite of the rolls where the material is entering, will mark the surface of the strip.

According to this invention, a volatile substance such as methyl alcohol or other quick-drying alcohol, benzene, gasoline, etc., is placed either on the roll surfaces or on the surfaces of the strip or on both, the volatile substance being allowed to evaporate to substantially complete dryness, leaving only a very thin, invisible, tightly adherent film on the surface of the roll or the material before the rolls and material come into contact with each other. As used herein, the term invisible is intended to denote that condition wherein all apparent wetness has disappeared. As shown in the drawing, the substance is sprayed onto the rolls at an angle of about 270 prior to the contact of the rolls and the strip by a series of upper spray heads 16 and lower spray heads 18. The upper spray heads 16 spray the substance onto the upper roll 12, and lower spray heads 18 spray the substance onto the lower roll 14 in a manner that will be described presently. An upper wiper 20 made of felt or other suitable cloth or absorbent material is placed against the upper roll 12 and serves to spread the substance evenly on the roll, and also to wipe off any excess. Similarly, a lower wiper 22 of felt or other suitable absorbent material is placed against the lower roll 14 and serves to spread the substance evenly on the roll and also to wipe off any excess. The rate of spraying of the substance is adjusted in a manner to be described presently such that the substance will have substantially completely evaporated .before the rolls contact the surface of the material being rolled, and that remaining on the rolls will be only a very thin, invisible, tightly adherent film. This film left from the evaporation of the substance imparts to the rolling operation the characteristics of rolling with a lubricant in that substantially increased elongation occurs over that of dry rolling at the same mill settings, but does not have the detrimental characteristics of rolling with a lubricant in that it does not mark the surface of the steel being rolled.

Although the drawing illustrates substance on both the top and bottom rolls and this is preferred, substantial benefit can also be derived by placing the substance on either the top or the bottom roll alone. Also, instead of spraying the volatile substance on eitheror both of the rolls, or in addition to spraying the rolls, it may 'be placed on the surface of the strip at a location sufiiciently removed from the bite of the rolls that it will have evaporated, leaving only a thin, invisible, tightly adherent film before the strip enters the roll bite. A Wiper also is desirable to spread the substance evenly on the strip surface and remove any excess.

Many volatile substances have been used to practice this invention, including those listed above. The only requirement is that the substance be sufficiently volatile so that when it is applied to the roll or to the strip, it will evaporate before the strip and roll come into contact at the bite of the rolls.

The spraying arrangement shown in the drawing is the preferred way of getting the volatile substance onto the the use of a volatile rolls, but other ways can also be used such as dripping the substance on or wiping it on with a saturated cloth, the only requirement being that it cover the surface of the roll or the strip and that it be evaporated to a thin, invisible, tightly adherent film before the material enters the bite of the rolls.

In the arrangement shown in the drawing, a spraying system is shown which includes a container 24 of the substance to be sprayed. The container is connected by a pipe 26 through a valve 28, a gauge 30, pressure regulator 32, and a filter 34 to a source of air supply designated generally as 36. The regulated air pressure delivers the substance from the container 24 through pairs of hoses 38 and 40 to each of the spray heads 18 where it is sprayed onto the roll 14. A similar spraying system (not shown) is connected to the upper spray heads 16 in a similar manner. Such a spraying system is sold by the DeVilbiss Company, Toledo, Ohio, and is described in their parts list No. 48l0-A. The amount of spray delivered from the spray heads can be controlled either by varying the head openings or the pressure, or by spraying intermittently. The intermittent spraying may be accomplished by providing a conventional timing device designated generally as 42, which timing device operates an electrical valve 44 between an open and closed position, the timing device being adjustable to switch the valve between positions at selected intervals of time, thereby causing an intermittent spray.

Although this invention has been shown and described with reference to particular embodiments, various adaptations and modifications may be made without departing from the scope and appended claims.

I claim:

1. In the method of temper rolling a steel strip member in a rolling mill having a pair of roll members, the improvement which comprises, placing a volatile substance on the surface of at least one of said members, said substance being placed on at a location and in an amount such that it will have evaporated leaving only a tightly adherent, thin, invisible film at the bite of the rolls as the material is entering the mill, and thereafter temper rolling the steel strip whereby said film provides increased elongation without detrimentally marking the surface of the strip.

2. The method of claim 1 wherein the substance is spread on the surface of the member by a wiper prior to evaporation.

3. The method of claim 1 wherein the volatile substance is a material selected from the group consisting of alcohol, benzene, and gasoline.

4. In the method of temper rolling steel strip in a rolling mill having a pair of rolls, the improvement which comprises, placing a volatile substance on the surface of at least one of said rolls, said substance being placed on at a location and in an amount such that it will have evaporated leaving only a tightly adherent, thin, invisible film at the bite of the rolls as the material is entering the mill, and thereafter temper rolling the steel strip whereby said film provides increased elongation without detrimentally marking the surface of the strip.

5. In the method of temper rolling steel strip in a rolling mill having a pair of rolls, the improvement which comprises, placing a volatile substance on at least one surface of said strip, said substance being placed on at a location and in an amount such that it will have evaporated leaving only a tightly adherent, thin, invisible film at the bite of the rolls as the material is entering the mill, and thereafter temper rolling the steel strip whereby said film provides increased elongation without detrimentally marking the surface of the strip.

6. In the method of temper rolling steel strip in a rolling mill having a pair of rolls, the improvement which comprises, spraying a volatile substance on the surface of at least one of said rolls, said substance being placed on at a location and in an amount such that it will have evaporated leaving only a tightly adherent, thin, invisible film at the bite of the rolls as the material is entering the mill, and thereafter temper rolling the steel strip whereby said film provides increased elongation without detrimentally marking the surface of the strip.

7. The methodof claim 6 wherein the substance is spread by a wiper over the surface of the roll prior to its evaporation.

8. In the method of temper rolling a steel strip member in a rolling mill having a pair of roll members, the improvement which comprises, spraying a volatile substance on the surface of at least one of said members, said substance being placed on at a location and in an amount such that it will be evaporated leaving only a tightly adherent, thin, invisible film at the bite of the rolls as the material is entering the mill, spreading the substance by means of a Wiper over the surface on which it is sprayed prior to its evaporation, and thereafter temper rolling the steel strip whereby said film provides increased elongation without detrimentally marking the surface of the strip.

9. In the method of temper rolling a steel strip member in a rolling mill having a pair of roll members, the improvement which comprises, spraying methyl alcohol on the surface of at least one of said members, said alcohol being placed on at a location and in an amount such that it will have evaporated to substantial dryness leaving only a tightly adherent, thin, invisible film at the bite of the rolls as the material is entering the mill, and thereafter temper rolling the steel strip whereby said film provides increased elongation without detrimentally marking the surface of the strip.

10. The method of claim 9 wherein the sprayed onto at least one roll member.

11. The method of claim 9 wherein the sprayed onto the surface of the strip member.

12. The method of claim 9 wherein the alcohol is spread over the surface by a wiper prior to its evaporation.

alcohol is alcohol is References Cited by the Examiner UNITED STATES PATENTS 2,258,930 10/1941 Haefner 7242 2,659,252 11/1953 Kipp 72-42 CHARLES W. LANHAM, Primary Examiner.

H. DIETER HOINKES, Assistant Examiner.

Claims (1)

1. IN THE METHOD OF TEMPER ROLLING A STEEL STRIP MEMBER IN A ROLLING MILL HAVING A PAIR OF ROLL MEMBERS, THE IMPROVEMENT WHICH COMPRISES, PLACING A VOLATILE SUBSTANCE ON THE SURFACE OF AT LEAST ONE OF SAID MEMBERS, SAID SUBSTANCE BEING PLACED ON AT A LOCATION AND IN AN AMOUNT SUCH THAT IT WILL HAVE EVAPORATED LEAVING ONLY A TIGHTLY ADHERENT, THIN, INVISIBLE FILM AT THE BITE OF THE ROLLS AS THE MATERIAL IS ENTERING THE MILL, AND THEREAFTER TEMPER ROLLING THE STEEL STRIP WHEREBY SAID FILM PROVIDES INCREASED ELONGATION WITHOUT DETRIMENTALLY MARKING THE SURFACE OF THE STRIP.

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