US1060764A - Method of making steel bars. - Google Patents

Description

H. R. JONES, E. L. HANG & J. MOGONNELL.

METHOD OF MAKING STEEL BARS.

APPLICATION FILED AUG. 16, 1912.

Patented May 6, 1913.

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APPLICATION FILED AUG. 16, 1912.

1,06%764. Patented May 6, 1913.

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unrrun s'ratrns HARRY R. JONES, EDWARD L. H ANG, AND JOHN MCCONNELL, OF CANTON, OHIO, AS-

SIGNORS TO THE UNITED STEEL COMPANY, OF CANTON, OHIO, A CORPORATION OF OHIO.

METHOD OF STEEL BARS.

Specification of LettersPatent.

Patented Mayo, 1913.

To all whom it may concern.

Be it known that we, HARRY R. J ONES, EDWARD L. HANG, ,and JOHN MoCoNNnLL, all citizens of the United States, and allresiding at Canton, in the county of Stark and State of Ohio, have invented a new and useful Method of Making Steel Bars, of which the following is a specification.

The invention relates to the art. of rolling steel from ingots into bars; and the objects of the improved method are to save some of the waste, and to expose and minimize some of the defects incident to the ordinary methods in use, and especially to produce a steel bar having a more compact and homogeneous structure throughout its body than has resulted from prior methods of rolling.

The objects of the invention thus set forth in general terms, are attained by the improved method of making the steel bars from slab ingots, illustrated in the accompanying drawings, forming part hereof, in which Figure 1, is a perspective view of a substantially square ingot ordinarily used for making steel bars, the same being laid upon one side and showing some of the deferts frequently present therein; Fig. 2, a perspective view of a billet rolled from such an ingot by ordinary methods, showing thedevelopment of the several defects into partially formed snake and pipe flaws, and showing the ordinary division or severing of .the billet into sections for rolling into bars;

Fig. 3, a fragmentary perspective view of a bar longitudinally rolled by ordinary methods from such a billet-section, showing the finaldevelopment of one of the defects into being the first step in the improved method, showing the development of the defect into partially formed snake and pipe flaws, and showing the division or severing of the slab into short sections for carrying outth'e improved method of cross-edge rolling; Fig. 7, a fragmentary side elevation of a pair of rolls showing an end view of the improved form of slab-section and, in succession, the various cross-sections into which the same is reduced by the rolls to form a bar by the improved method. Fig. 7 an end-edge view of one of the improved slab sections.- Fig. 8, a perspective view of one of the improved slab-sections, showing the partial development of a snake. seam in the side thereof; Fig. 9,'a fragmentary perspective view of a bar rolled from the same slab-section, showing the complete development of the snake seam in the sidethereof; Fig. 10, a perspective view of one of the improved forms of severed slab-sections showing the partial development of a pipe hole in the end-edge thereof; and Fig. 11, a fragmentary perspective view of a bar rolled from the same slab-section, showing the complete develo ment of a pipe seam in the side, instea of a pipe hole in "the body thereof.

In molding the square ingots 1, or the slab ingots 2, of molten met-a1, certain irregularly shaped shrinkage cracks, as 3 or 4, commonly called snakes, are formed in the sides of the ingots from the accumula tion of unexpelled air or other gases; and a porous or spongy formation, as 5 or 6, commonly called a pipe, is frequently formed in the upper end of the ingots, which porous formation extends longitudinally into't-he body of the ingot and may be caused by the escape of air and other gases while the ingot is being molded. At any event,these defects, which are illustrated in Figs; 1 and 2, are well known and recognized by manufacturers of steel, the former defect usually developing into what is commonly known as "a snake seam; and the latter defect usuallydeveloping into what is commonly. known as a pipe hole, in the finished bar.

When a squareingotis rolled longitudinally inthe usual manner, and is elongated to form the billet 7', shown in Fig. 2, the snake 3 in the side thereof is elongated and forms apartially developed snake seam"3 extending a comparativelyv short distance along the side of the billet; and the porous or spongy formation 5 in the end of the ingot, is concentrated and more clearly defined and somewhat extended, and forms the partially developed pipe hole 5 in the body of the billet; after which the billet is severed, as at 8, into a series of sections 9,

9, 9 and 9, which'are ordinarily further reduced by a longitudinal rolling to form finished bars, as 10 andlO, shown in Figs.-

ing within and along the correspondingportion of the finished bar; but this defect, not appearing on the surface of the bar,-cannot be detected, and the bar discarded as in the case of the snake seam, so that bars containing pi e holes find their way into the market, an such flaws are only detected after the steel has been manufactured and placed intouse, as in automobile gearings and other parts requiring absolutely homogeneous and flawless steel, wherein the-flaw ultimately results in a breakage of the part when the same is in use. These ditficulties are either lar ely avoided or considerably minimized, an the pipe flaw is exposed as a seam in-the side of the finished bar, by the improved method of making the bar by the present invention, wherein a slab-ingot 2 is rolled into a slab 11 by a universal mlll, in which the edges as well as the sides of the ingot and the resulting slab are subjected to compressing action of the corresponding rolls; which slab 11 is then severed into the series of sections, 12, 12, to-12 'and 12, inclusive, of a length somewhat greater than the thickness of the slab; which slab:

sections are then reduced by rolling crosswise of the severed edges in rolls having grooves of gradually decreasing depth, until a substantially square cross section is formed; which reduced section is then further reducedby the ordinary methods of rollin into a rod having a round or other desire section.

And, in the second case, the par .ture. two or more times, as n the grooves 15, 16

amination of a 'longitudinal face of the' metal shows a much larger or coarser crystalline structure than appears in a transverseface thereof. The slabs thus rolled, are transversely severed either by shears or other means of cutting, into a series of sections, 12, 12 to 12 and 12, which sections are severed with a greater dimension along the original grain or slab than the dimension of the depth thereof, the difference in dimensions being preferably in the ratio of about two to one, although this particular ratio is not essentiaL- .Each slab-section "12,

12*, etc, is then reduced by heating in the usual'manner and then passing between a pair of rolls 13, the several passes being made successively in the series of grooves as 14 to 22, inclusive, to form the finished bar 23, which may be of any" shape in crosssection, as for instance, 'the round form shown.

The initial passing of the slab-section between the rolls is made by presenting to the nip of the rolls one edge-end 24 of the slabsect-ion being the end originally forming part of the edge of the slab, which brings the sides 25 of the section originally formin part of the side of the slab, between the si es of the grooves 14; the severededges 26 of the slab section, that is, the end formed by'the cutting of the slab across the grain thereof, being impinged and compressed be-,.

tween the opposing bottoms of the grooves 14, so that the slab-section is elongated by a compression exerted along the line of the" grain of the original slab, throughout the Y entire extent thereof with the result that the structure of the metalis, as it were, upset and the grain thereof is compressed endw1se into a compact and substantially homogeneous condition, the fibrous structure of the grain being substantially eliminated, and the relatively coarse crystalline structure being reduced to a much finer crystalline struc- This method of' rolling is repeated and 17 of the rolls, these grooves being respectively formed Twith gradually decreasing depths, so that by each pass the slabsection is reduced by a displacement of the.

metal between the end-edges 26 which were originally formed by the transverse cut of bar is finished by a succession. of passesin the grooves 18 to 22, inclusive, to form the cross-sections 18 to 22*, inclusive, in the usual manner.

By this method of cross-edge rolling the slab sections, the body of the finished bar is reduced to an exceedingly compact and s ubstantiallyhomogeneous structure not having any appreciable grain, and having a more uniform and finer crystalline structure than is produced by the ordinary methods of rolling; and it has been found that-manufactured products made from steel bars thus rolled have a much greater strength and endurance against the shocks, and strains of compression, torsion and tension, than is found in steel rolled in the ordinary manner. Furthermore, referring to Fig. 6, it is evident that the partially developed snake seam 4: is limited to a certain section, as 12". into which the slab is severed, so that a flawless finished bar can be rolled from the other sections, as 12 and 12 at this end of the slab, by the improved cross-edge method of rolling; and by referring to Fig. 6, showing the section l2 containing the partially developed snake seam 4*, it is evident that if the same does not extend too deep in the side 25 of the slab-section, this side can be planed down to the bottom of the defect, in the usual manner well known in the art, for rolling a flawless. bar without waste. If, however, such treatment of the slab-sec tion is overlooked or neglected, it is evident that the improved cross-edge rolling herein described, will serve to some extent to eliminate the incipient seam by the compression of the slab-section along the length of the extended snake and the lateral pressure thereof against the sides of the roll grooves; but at any event, the extension of the'slabsection cross-wise of the partly formed snake seam 4, does not extend the defect throughout the whole length of the finished bar 23, but only produces the completely formed snake seam 4 in a relatively small portionof the, bar, as Shown in Fig. 9, so that it is only necessary to cut out and waste this comparatively small portion of the bar, leaving the remainder thereof in perfect form without 'any' flaw therein. And finally it will be noted that the crosscutting of the slab transversely severe and exposes the partly formed pipe hole 6 as shown in Fig. 10, and when the same is discovered, permits the slab-section contain-- ingthis obvious defect to be thrown out and re-smelted without any further expense.

But if such defect is not detected or is neglected, it is evident that the improved crossedge rolling of the slab-section will serve'to some extent to eliminate the defect, and at any event the improved method of rolling the slab-section-always brings this defect to the surface of the finished bar, as the completely formed pipe s eam 6 which however, extends only throughout an'intermediate portionof the whole extent of the finished bar formed by the slab-section, as shown in Fig. 11, and bycutting out and discarding this portion, the remaining end portions are left in perfect condition for use.

I By this improved method of cross-edge rolling the slab-sections, it is evident that there is no possible chance of producing a pipe hole in the body of'the finished bar, but that ing a very uniform condition of the bar or metal in all directions, whereas, .by the ordinary methods of rolling, it is well-known that the longitudlnal strength'of the bar or 'metal is greater than the transverse strength thereof.

We claim:

1. The method of making steel bars which consists in reducing slab-ingots to slabs by pressure on both sides and edges thereof, then transversely severing the slabs into sections of greater length than depth, then cross-edge rolling the slab sections to compress them endwise of the origihal length of the slab, and then reducing to bars of the desired cross-section.

2. The method of making steel bars which consistsin transversely severing longitudinally rolled slabs into sections of greater length than depth, then cross-ed e rolling the slab-sections by'compressing't em endwise of the original length and retaining them flatwise of the original depth of the slab to a substantially square cross section, and then reducing 'to bars of the desired cross-sectlon.

f. The method of making steel bars which consists in transversely severing longitudinally rolled slabs into Sections of greater length than depth, then cross-edge rolling the slab-sections to compress them endwise of the original lengthof the slab to a substantially square cross-section, and then re ducing to bars,of the desired cross-section.

4. The method of making steel bars which consists in transversely severing longitudinally rolled slabs into sections, then crossedge rolling the slab-sections to compress them endwise of the original length of the slab throughout the extent of its severed faces, and then reducing to the desired crosssection.

5. The method of making steel bars which consists in cross-rolling a slab-section having a grain to compress it endwise of the grain throughout. the extent of the section, and then reducing to the I desired crosssection.

' 10 6. The method of making steel bars which includes the step of cross-rolling'a slab-section having a grain to compress it endwise of the grain throughout the extent of the section.

HARRY R. JONES. EDWARD L. HANG. JOHN MOCONNELL. Witnesses:

HARRY FREASE, CHAS. M. BALL.

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