US3281290A

US3281290A - Open coil annealing

Info

Publication number: US3281290A
Application number: US351281A
Authority: US
Inventors: Raymond C Plate
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1964-03-09
Filing date: 1964-03-09
Publication date: 1966-10-25
Anticipated expiration: 1983-10-25

Description

Oct. 25, 1966 R. c. PLATE 3,281,290

OPEN COIL ANNEALING Original Filed Aug. 31, 1961 l/VI/E/VTOR RA YMO/VD 6. PLATE Attorney United States Patent Office 3,281,290 Patented Oct. 25, 1966 3,281,290 OPEN COIL ANNEALING Raymond C. Plate, Monroeville, Pa., assignor to United States Steel Corporation, a corporation of Delaware Continuation of application Ser. No. 135,214, Aug. 31, 1961. This application Mar. 9, 1964, Ser. No. 351,281 1 Claim. (Cl. 148134) This application, which is a continuation of my copending application Serial No. 135,214, filed August 31, 1961, now abandoned, relates to open coil annealing and more particularly to a method of annealing coils of steel strip with a particular type of separator therein. Open coil annealing is described in an article by Arnold in the August 1960 issue of Iron and Steel Engineer and also in an article by Bausher in the May 1961 issue of Iron and Steel Engineer. The usual practice in open coil annealing is to place a nylon cord between the convolutions of the coil to separate the same and then remove the cord before annealing the coil of strip. Since the nylon cord has to be removed from the coil before it is placed in the furnace for annealing, uniform spacing of the convolutions of the coil is not assured. For this reason other types of separator elements have been suggested, but none of these have proved satisfactory for various reasons. For example, some become crushed in use so that they cannot be reused. This also prevents adequate circulation of the atmosphere gas. Others are of such shape that they cannot provide for adequate circulation of the atmosphere gas. In some cases the materials used were such that they could not readily be wound on a spool for handling.

It is therefore an object of my invention to provide a method of annealing coils of strip in which the separator remains in the coil during the annealing cycle and can be readily removed and prepared for reuse.

This and other objects will be more apparent after referring to the following specification and attached drawings, in which:

FIGURE 1 is a schematic plan view of apparatus suitable for placing the separator in position in a coil;

FIGURE 2 is a schematic view showing a coil in an annealing furnace;

FIGURE 3 is an enlarged view taken on the line III-III of FIGURE 2; and

FIGURE 4 is a view taken on the line IVIV of FIG- URE 3.

Referring more particularly to the drawings, reference numeral 2 indicates a rotatable table for receiving a tight wound coil of strip C. A rotatable table 4 is provided in spaced apart relationship to table 2 for supporting a loose coil C of strip. A separator removal boom 6 may be located above the table 4. An unwinder 8 is provided adjacent the table 4 for rotatably supporting a reel 10 carrying an elongated separator 12. The separator 12 consists of a relatively straight wire 14 having a wire 16 spiraled therearound.

An annealing furnace 18 for annealing coils of strip C is shown in FIGURE 2 and basically consists of a base 20 for supporting the coil of strip C, a fan 22 for circulating deoxidizing gas through the coil C within an inner cover 24 and an outer cover 26 surrounding the inner cover 24 for providing the annealing heat. The apparatus shown in FIGURES 1 and 2 are conventional and is therefore shown schematically with details being omitted. The apparatus shown schematically in FIGURE 1 is preferably like that shown in the Iron and Steel Engineer articles mentioned above and the apparatus shown in FIGURE 2 can be similar to that shown in Woodson Patent No. 2,137,869 dated November 22, 1938 and Munford Patent No. 2,546,697 dated March 27, 1951.

In making up the separator 12 the inner wire 14 may be made of low carbon hard drawn steel and the outer wire 16 of a softer mtaerial such as annealed low carbon steel. However, stainless steel, which can withstand the annealing heat without damage has proved to be very successful in use. However, the straight Wire 14 should always be harder than the outer wire 16. The diameter of outer wire 16 is preferably at least as great as the diameter of the wire 14. The number of twists of the outer wire per inch may vary. For example, three or four twists per inch may be used, but this may be varied as desired to increase the space available for circulation of the atmosphere gas. To prevent the separator from sticking during the annealing cycle it is preferably annealed after formation thereof.

In carrying out the method of my invention a tight coil of strip C is mounted on the tables 2 and fed therefrom to the mandrel 4C of table 4. Separator 12 from reel 10 is fed to a position above table 4 and fastened to the end of the steel strip after which the table 4 is rotated to pull the strip from the coil C so as to position the separator 12 between the convolutions of the coil C as it is formed. It will be seen that

spaces

28 and 30 are provided between the wire 14 and the convolutions of strip on each side thereof. The amount of space available for such circulation of gases may be increased by increasing the pitch of the spirals of wire 16. The coil C with the separator 14 therein is removed from table 4 and placed on base 20 after which the inner cover 24 and outer cover 26 are placed thereover and heat is supplied thereto with the fan 22 circulating the atmosphere gas through the open convolutions of the coil. After the annealing cycle the separator 12 may be removed from the coil C at the furnace site and rewound on a reel 10 or the coil may be returned to the table 4 and the separator 12 removed by means of the boom 6 as described in the Iron and Steel Engineer articles.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claim.

I claim:

In a method of annealing coils of steel strip which comprises coiling the strip about a vertical mandrel with a separator between the convolutions of strip, annealing the coil with the separator therein and its axis vertical wherein atmosphere gas passes between the convolutions of the strip during annealing; the improvement comprising utillizing a separator including a center wire the axis of which forms the longitudinal axis of the separator, and an outer wire spiraled about said center wire over a majority of the length thereof, the number of twists of the outer wire being a maximum of four per inch, with adjacent spirals being spaced from one another at substantially uniform pitch to provide a space therebetween, at least one of said wires being made of stainless steel.

References Cited by the Examiner UNITED STATES PATENTS 379,535 3/1888 Hewitt 57145 (Other references on following page) UNITED STATES PATENTS FOREIGN PATENTS s l i 57 144 512,811 9/1939 Great Britain.

Lancaster 174 42 OTHER REFERENCES Peterson. 5 Blickwede: Journal of Metals, August 1961, relied on, DAvaucourt. P

Wilson- 266-5 DAVID L. RECK, Primary Examiner.

Wilson et a1. 263-40 C. N. LOVELL, Assistant Examiner.

Claims

1. IN A METHOD OF ANNEALING COILS OF STEEL STRIP WHICH COMPRISES COILING THE STRIP ABOUT A VERTICAL MANDREL WITH A SEPARATOR BETWEEN THE CONVOLUTIONS OF STRIP, ANNEALING THE COIL WITH THE SEPARATOR THEREIN AND ITS AXIS VERTICAL WHEREIN ATMOSPHERE GAS PASSES BETWEEN THE CONVOLUTIONS OF THE STRIP DURING ANNEALING; THE IMPROVEMENT COMPRISING UTILLIZING A SEPARATOR INCLUDING A CENTER WIRE THE AXIS OF WHIC FORMS THE LONGITUDINAL AXIS OF THE SEPARATOR, AND AN OUTER WIRE SPIRALED ABOUT SAID CENTER WIRE OVER A MAJORITY OF THE LENGTH THEREOF, THE NUMBER OF TWISTS OF THE OUTER WIRE BENG A MAXIMUM OF FOUR PER INCH, WITH ADJACENT SPIRALS BEING SPACED FROM ONE ANOTHER AT SUBSTANTIALLY UNIFORM PITCH TO PROVIDE A SPACE THEREBETWEEN, AT LEAST ONE OF SAID WIRES BEING MADE OF STAINLESS STEEL.