US2080159A - Process of treating steel - Google Patents

Description

Patented May 11, 1937 Robert 5. Afcher' 'Chicago, nix-assignedTiiff Republic Steel CorporatioiipYodn a corporation of:New.Jers'ey-' 1": i

No Drawing] stonian J a ssa seiiaK 54?? R n e nam- 23 s was. (CLL'ZZQ-ZMW This invention relates to the art 'of ageing metals, and-particularly to a method of prevent ing the formation of so-cailed' "hair linesea'nis" in steel articles.

Certain steels, as made by:{o niin ar y methods;

a hai contain so-called hair line seams". These. seams are not seams in the sense of ncr'eyiceal-T' but are bodies of non met'aiiic material'pccl ided in the steel; "Usually these seains'fl ar pa'raiiei 10 to and just'belov'i the surface 'of roliedsteel' arf ticies;- They areusualiy in the Ior'm of elongated" bodies' ot smali' thickness, much: like ,haii'sfltls quite'ditlicult'to detect sachffsfl usual laboratory apperac'usi includ ng s i o s. scope, blit'tliey can be located'by machining' 'the' steel 'articie parallel" to its irons axisg In "s cases; thei appear as" lines jresembling'fjcrackslofl example,- if -a round rolled" her" containing "seams"- is centereddn ajlathe, rotated a out" its]. long axis'an'd the surface layer is machined-oil,

the axially extendingsearns" inthemachinfedj surface can bedetected. Deeper seatedfseam'sf that giiy-. method-;may-be ems pioyd advantageously on a wide range oi-steels whereinthegeexists any; tendency to formation, of line jseams' l t se e.z ns probable that the high meltingllqllgt-ilollymetallicsubstances which i he fiesaan imss iaxe in l ions in he e but er vs osea sa li ovh r l ape by ..QQQQfiPfiQQQQfiaJ: qfi 'ai 11-1- 2 9 EQWQEQ-fllfihbfih a-l fi -r 3 1 7. 9? e lfii illi .mqiwqslnin numbexi'and soften 10 m iisdicqmnie lv hmas ios-thesieeunmr mggi g and reggtive atgaosnhereoonsisting largely 1 would pre er to use chlorine assuchbutaln Order.

I to. maintain proper working conditions around .Q. compounds such gsea rmntetrachloridea 2:

ii e 99. 1.21 51$19..mi$n oxicmhlorine a 4 1 9 iiwail aed. hlorioeanaparbonmas l F 1 .3559: ener l. any. chlorine com: ss: mm naa isnw de ompose under theilemperitures presentin the mold during casting and 'will libeiate chlorine in adequate amounts.

may similarly be located by taking {urthercuts ofithe bar. Generallrspeaidng. mostofisuchjj "seams" are found irithe"artic le iustbeiowithe surface, but oi'te'nsome are""i'ound" a t ffgreater depths below the surface. These .hair ,line f. seams" are quite objectionable insteel'articies;lntended for certain uses and render such articles";

unsatisfactory amounts. Q

I have discovered that the "hair line seams are more often encountered in steels which contain ingredients which, under ordinary Ltreatlngaand' casting conditions, tend to form in the steel nonmetalllc substances of higher fusing point than that of the steel. For example, these seams" are common under prior, standard, steel making 0 practices. in steels of the SAE 2345 type have the following general composition if present in excess of certain f by the presence of oxidized deoxidizers in the which "Jcor'iium' 'or th like are added to the steel in the for the'inteiidedipiupo'se" may housed. {believe thatiwhaiieverearbon 6mm enmay'be pres-Q unneccssary'in bringing about the 'desired results" and; asstated above: would prefer 'tous'e chlorine gas .except that .it tends to make 'unsat'isfacto the worlsfins.:conditlons--about the-molds 3o Lbelievgthatthe hair=line.seams" are" caused steel. Ordinarily, deoxidizers, such as small amounts pi manganese, silicon, aluminum, ziri'urnace, in the ladle or in the mold. These sub- 35 stances oxidize more or less-completely and their oxides may remain entrapped in the steel. They may react with other non-metallic substances toforrn complex compounds. Many of these oxids or substances or compounds are relatively infusible. Where aluminum is the deoxidizer These steeis,. as well as others in the SAE 23 O( l" series, and other steels including steelsfioi the SAE 1000 series, which contain betweenabout seams'flhave beemfound in steel of the'S'AE 2345 type to which. between ip iind and 1 pound of aluminum erson-mu been added as a deoxidizer andiu whichisubstantlally-all the aluminum had been oid clized Treatment of similar steel by the present process has greatly reduced the number of "hair line seams."

In practicing the present process in a preferred manner. I tap the molten steel into a ladle and add the usual amounts of metallic deoxidizer. Then I drop, pour in a small stream, or otherwise suitably introduce, liquid carbontetrachloride into a mold for example, an ingot mold, just before, 6 and also during, pouring of the molten steel into the mold. Between about two pounds and about four pounds of this liquid for each 21" duodecagon mold making a 7500 pound ingot is sufficient for the desired results. This liquid vaporizes at once and being heavier than air tends to expel some oi the air and dilute the remainder, particularly at the surface of the pool of metal in the mold and to a greater or lesser extent around the flowing stream of steel.

Two to four pounds of carbontctrachloride per 7500 pounds of steel is roughly A to lpound per ton of steel. Good results have ibeen obtained with as little as about V pound per ton and also with more than 1% pounds of ca'rbontetrachlm ride per ton of steel. 2

The foregoing treatment gives unexpected results. Considerable quantities of oxides collect in the form of lumps on the tops of ingots. No such collection of lumps occurs during the-or dinary pouring of the same kindof steel. Collection of oxides in lump form as a result of the present process is believed to-be due to some physical or chemical change in the oxides in the metal which is brought about by the foregoing treatment. Chemical analysis made of these lumps has given the following ingredients and percentages thereof 4 Percent FeO 4.5 mo 14.11 S10 12.10 A1201 51.0 CaO 1.15 1, 2.0 MgO irace It seems probable that these lumps are collections of the dispersed substances which cause hair line seams, for chemical analyses of foreign material found in such seams shows between about and about of A120: and between about 20% and about 45% of s10. lay-methods of analysis in which the oxides of iron. manganese and calcium were removed before determination of 50 A120: and S102.

can'rrrrci'rs Patent No. 2,080,159.

Whatever may be the action which takes place by reason of the present process, the unexpected and practical result is that the number and size of hair line seams is greatly reduced, if not more or less completely eliminated, and quantities of 5 foreign material otherwise found in hair line seams collects in the form of lumps on the surface of the ingot.

It will be understood that the time when the metallic deoxidizer is added to the steel is not critical on the present process. For example, the deoxidlzer may be added in the furnace or in the mold and improved results, as regards decrease in the number of seams" may be obtained.

I have thus described my invention in detail so that others skilled in the art may understand and be able to practice the same, but not for the purpose of definingthe scope of my invention.

The scope is defined in what is claimed.

What is claimed is:

1. The method of treating steel to prevent the formation of hair line seams in articles rolled from such steel, which includes the steps of adding to molten steel a small amount of a metallic deoxidizer and bringing such steel into a mold containing carbon tetrachloride, a chlorine rich atmosphere, thereby collecting and bringing to the top surface of the steel "seam causing" oxides.

2. The method of treating steel to prevent the formation of "hair line seams" in articles rolled 80 fro'r'n such steel which includes the steps of making molten steel containing between about 30% and about 1.00% of manganese, adding thereto a small amount of a metallic deoxidizer, and collecting oxidized deoxidizers by bringing such steel into a mold together with between about 54 pound and about 1% pounds of carbontetrachloride per ton of steel, part of the carbon tetrachloride being placed in the mold before the steel enters the mold.

3. The method of treating steel which includes the of adding a small amount of metallic deoxidizer to molten steel containing manganese and collecting non-metallic oxides in the form of lumps on the top surface of the steel by pouring 4.5 such steel into a mold and bringing into the mold shortly prior to and during such pouring between about one-quarter pound and one and one-half pounds of carbon tetrachloride per ton of steel.

ROBERT S. ARCHER. 50

OF CORRECTION liay 11. 1937.

ROBERT .8. ARCHER.

It is hereby certified that error appears in the printed specification' of the above numbered patent requiring correction as follows:

first column, line 43, for ".50" read line 26, claim 1, strike out the words Page 1, .90; and page 2, second column,

"carbon tetrachloride"; and that the said Letters Patent should be read with these corrections therein that the same nayconrorm to the record of the case in the Patent Office.

Signed and sealed this 29th day of June, A. D. 1937.

(Seal) Henry Van Arsdale Acting Oat-1on0:- of Patents.

add the usual amounts of metallic deoxidizer. Then I drop, pour in a small stream, or otherwise suitably introduce, liquid carbontetrachloride into a mold for example, an ingot mold, just before, 6 and also during, pouring of the molten steel into the mold. Between about two pounds and about four pounds of this liquid for each 21" duodecagon mold making a 7500 pound ingot is sufficient for the desired results. This liquid vaporizes at once and being heavier than air tends to expel some oi the air and dilute the remainder, particularly at the surface of the pool of metal in the mold and to a greater or lesser extent around the flowing stream of steel.

Two to four pounds of carbontctrachloride per 7500 pounds of steel is roughly A to lpound per ton of steel. Good results have ibeen obtained with as little as about V pound per ton and also with more than 1% pounds of ca'rbontetrachlm ride per ton of steel. 2

The foregoing treatment gives unexpected results. Considerable quantities of oxides collect in the form of lumps on the tops of ingots. No such collection of lumps occurs during the-or dinary pouring of the same kindof steel. Collection of oxides in lump form as a result of the present process is believed to-be due to some physical or chemical change in the oxides in the metal which is brought about by the foregoing treatment. Chemical analysis made of these lumps has given the following ingredients and percentages thereof 4 Percent FeO 4.5 mo 14.11 S10 12.10 A1201 51.0 CaO 1.15 1, 2.0 MgO irace It seems probable that these lumps are collections of the dispersed substances which cause hair line seams, for chemical analyses of foreign material found in such seams shows between about and about of A120: and between about 20% and about 45% of s10. lay-methods of analysis in which the oxides of iron. manganese and calcium were removed before determination of 50 A120: and S102.

can'rrrrci'rs Patent No. 2,080,159.

Whatever may be the action which takes place by reason of the present process, the unexpected and practical result is that the number and size of hair line seams is greatly reduced, if not more or less completely eliminated, and quantities of 5 foreign material otherwise found in hair line seams collects in the form of lumps on the surface of the ingot.

It will be understood that the time when the metallic deoxidizer is added to the steel is not 10 critical on the present process. For example, the deoxidlzer may be added in the furnace or in the mold and improved results, as regards decrease in the number of seams" may be obtained.

I have thus described my invention in detail 15 so that others skilled in the art may understand and be able to practice the same, but not for the purpose of definingthe scope of my invention.

The scope is defined in what is claimed.

What is claimed is:

1. The method of treating steel to prevent the formation of hair line seams in articles rolled from such steel, which includes the steps of adding to molten steel a small amount of a metallic deoxidizer and bringing such steel into a mold 25 containing carbon tetrachloride, a chlorine rich atmosphere, thereby collecting and bringing to the top surface of the steel "seam causing" oxides.

2. The method of treating steel to prevent the formation of "hair line seams" in articles rolled 80 fro'r'n such steel which includes the steps of making molten steel containing between about 30% and about 1.00% of manganese, adding thereto a small amount of a metallic deoxidizer, and collecting oxidized deoxidizers by bringing such steel into a mold together with between about 54 pound and about 1% pounds of carbontetrachloride per ton of steel, part of the carbon tetrachloride being placed in the mold before the steel enters the mold.

3. The method of treating steel which includes the of adding a small amount of metallic deoxidizer to molten steel containing manganese and collecting non-metallic oxides in the form of lumps on the top surface of the steel by pouring 4.5 such steel into a mold and bringing into the mold shortly prior to and during such pouring between about one-quarter pound and one and one-half pounds of carbon tetrachloride per ton of steel.

ROBERT S. ARCHER. 50

OF CORRECTION liay 11. 1937.

ROBERT .8. ARCHER.

It is hereby certified that error appears in the printed specification' of the above numbered patent requiring correction as follows:

first column, line 43, for ".50" read line 26, claim 1, strike out the words Page 1, .90; and page 2, second column,

"carbon tetrachloride"; and that the said Letters Patent should be read with these corrections therein that the same nayconrorm to the record of the case in the Patent Office.

Signed and sealed this 29th day of June, A. D. 1937.

(Seal) Henry Van Arsdale Acting Oat-1on0:- of Patents.