US1017908A - Manufacture of sheets or plates of manganese steel. - Google Patents

Description

-others' skilled the art to which it apper- OF 'N'EW YORK, N. Y.

rraxoracruanlor snnn'rs oarraras or momma srnnn v Specification of Letters Patent.

Application filed January 10, 1812. Serial No. 310,878.

To all whom it may eoncem: I Be itlknown that I, Wmrmno S. Porran, a citiz'enof the United States, and residing at the Ap, org Apartments, :atthe corner of 6. Broadwa. an Seventy-eighth street, .in the boron hwof Manhattan, in, the city, county,

and; tate=of New York, have inventedcer- .t'ain new, and useful Improvements in the Manufacture of Sheets or Plates of Manand I do hereby declare the j ollowing to be a full, clear, and exact de-- scriptionof the invention, suchras'wvillenabg tainsttomake and use thesame a In an ap lication for Letters Patent of the United tateqfiled by me under date of November'4th, 1911, Serial No. 658,425, I have-described the manufacture of sheets or 3 plates from manganesesteelbil-lets or blanks 1 (having g8 percentage of manganese above 5; percent. and usually containing about 12 7 gr the final vproduct of the operation ing of a substantiall uniform, fine ed condition throng out, and :having the desired stifinessor ductility appropriate to the usewfor which it ,is intended; V

In my application referred to, the method described involves first heating the manese steel :billet or sheet bar until it is Er d ught into a uniform and ductile condition throughout, ,appro riate to the rolling o tion'. Tothislen ,the necessary plasticity is imparted to the billet or sheet bar, by raising it to a temperature whiehrfor the 85 notion of the best results, will usually above the melting .point of the eutectic alloy, that is, above 1 125 G. (ea-y H25 .C.

to 1225" 0., according to the ductility required-for =rolling), but which, in some in- 40 stances, may he-asllow :as 1060 (3., provided.

submuent' reduction from the billet to the sheetror plate in .a single heat is not consid- 1 In accordance .with the present invention,

the blank in the condition of ductility to which it :has been :bro operation referred to, will :be thoroughly worked, by a partial rolling operation, which terminates .at .a temperature from to 800 {0. to 10W .0., andithereafter continu- I ing the rolling. ration with light pressure and slight uctions (according to the stifiness -.des1red) until .at the completion of the 0 ration, the-,stemperature has fallen'so lowt reversion ,outof the .uniforrmaustenite condition of thexmetal is impossible.

htaby the heating In; the ractice the present invention,';the 1n1t1al eating of the blankis preferably Patented Feb. 20,1912.

carried to temperaturesabove 1125" 0., {and the rolling, "u to the time of nearly completm there uction tofinished dimensions, shoul be-carried on rapidly, with considerable reductions in each stage of the rollin so that the steel is brought to a fine-grain wrought condition. Thereafter, the rol a wing; 1s preferably conducted inrolls whic are supplied with a considerable amount of cooling water, is so conducted that in each p age through these rolls, the metal is not nsidera' 'ly reduced or elongated, thereby stiffening of the roduct. This seco roll tinue unti :the metal approaches a black heat, or even below the black heat, that is,-

at temperatures ranging from 550 C. to 400? C., or lower.

It is characteristic of the present invention that :rolling in the ordinary manner, that isnyto say, with hea reductions, is avoided at temperatures be ow 800 0., and particularly below 720 0., below which latter -,temper ature rolling with hea reductions leaves the metal im a very st' :and brittle condition, similar to that produced by the cold-rolling or wire-drawing of mild steel, so that in such case, :a subsequent annealing operation is necessar to relieve the sheet or plateof strains or StlfillGSS. I have found, however, that by continuing the rolling at temperatures below this limit with ,a moderate amount of pressure, such, for example, as the weight of the ordinary sheet ,roll but with inconsiderable reductions or elongations, the metal is not only tough because of the avoidance of the excessive reduction at the lower heat, but ma be cooled entirely without having so cred those separations which would 'have wcurred during the cooling if not accompanied by the pressure of the rolls. For exam le, if the plate were brought to finished imensions by rolling until at a tem stature of above 720 and then air-coo ed until at the ordinary temperature, the air-cooled sheet havin sufiered alterations in cooling from 720 to 420 would lack the desired'ductility andtouglmess; whereas, subjected to the pressure of the rolls with but light reductions, the separations which might have at temperatures below 720 C. are avoided, and the finished sheet voiding any undue strainmfi or a n my an coinci entcool-ingshouldbeconis strong and tough, and has-a ductility correspondmg to the temperature at which the heavy reductions were terminated and the lighter reductions begun.

'By' sing wateron the rolls during therolling with but light: reductions, the more rapid cooling incident to the contactlwith thecold, wetvrolls further tends to obviate the separations incident to: slow cooling without applied pressure.

vHaving thus descrlbedf, intention, -what Iclaimlis;

l. 1.. The methodof making sheets or plates of. manganesesteel, which comprises heating a billet or blank of manganese steel,until in 1a uniform and. ductile condition thr'ough out, partially. rolling until :in, a thoroughly worked condition at temperatures. which, m

f the; finishing stage of, the partial rolling,

are between 800? C, and 10? 5 6., thereafter working with light pressure and but slight ured uctions until the temperature-has fallen solow that; reversion out of the uniform,

; austenite condition will not take place; substantially .fiS described.

2. "lhe method of making sheets or plates of manganese steel, which comprises heatmg a uniform and ductilecondition throughout, I

a billet or blank of manganese steel until in partially; rolling, until in a thoroughly worked condition at temperatures which, in

the finishing stage ofthe-partial rolling, are between 800 C. and 107 5 0., and thereafter working with'light pressure and but-slight reductions, together with gradual water- Vquenching until the temperature has fallen so low xhat reversion out of the uniform, austenite condition will not stantially as described.

3. The method 'of making sheets or plates of manganese steel, which comprisesheat:

ing a billet o'r'blank of manganese steel 1111-- til in a uniform; and" ductile condition throughout, partially rolli'ng until in a thoroughly worked condition at tem eratures which, 'in the finishing stage oi the partial rolling, are between 800 G.- and 107 5 C.,and thereafter workingzwith light pressure and but slight reductions-to, substanbtiailly 'a black heat {substantially as descrre "In testimony whereof I affixinj signature; .in presence i take place sub-'