US1066258A - Manganese-steel casting and process of producing the same. - Google Patents

Description

rinrra s'ra'rns. rarnn'r orrron.

Enoan ous'rnn, or PHILADELPHIA,. rzaivnsynvanm.

manoannsn-srnnn oasrnve AND Paoo'sss or PRODUCING THE SAME.

N Drawing".

Specification of Letters Iatent.

To alifwhomt may concern: g

Be it known that I, ltnsan A. .CUSTER, a-

I citizen of-the Unit-ed States, residing at Philadelphia, inthe county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in "iii Manganese-Steel Castings and the Process of lFroducing the Same, of which the following is a'specification.

, The primary object of this invention is to produce casting-s from manganese steel without reheating or subsequent treatment of any kind, which will have a uniformly fine,

even andclosely knit crystalline structure *and, besides possessing the usual hardness 'ofmanganese steel castlngs, Wlll also pos-- sess, though in "a non-annealedand nohquenched condition, the toughness and ductility which are usually characteristic only of manganese steel castings which have been reheated and quenched in the usual manner.

The invention consists in the novel prodnot itself and in the process by which that product is produced.

toughness or ductility, the crystalline struc-,

turo or molecular arrangement, dis'closedby the microscope, being relatively lar 'e and loosely knit before the castings are reheated and quenched or annealed. To increase the toughness and ductility of the castings it has been customary heretofore to reheat the castings to a relatively high temperature and then to quench the same by plunging them in water or by other-suitable means. This reheating of the castings, which is continued until the metal is in a somewhat soft and plastic condition, permits ajmolecular readjustment of the metal and. removes the internal stresses which result from slow cooling, and the effect produced by the quenching is to retain the desirable condition developed by the reheating, so that the castings, after being quenched are hard,

tough, and somewhat ductile instead of being hard and brittle, Microscopical examination of such cas tings, after reheating and quenching, shows some improvement in the crystalline structure, although it is not marked. The production of manganese steel castings which possess a desirable degree of Patented July 1, 1913." Application filed March 15, 1911. Serial No. 614,729.

toughness and ductility therefore requires three main operations, namely, the casting of the metal, the reheating. of the casting and the quenching of the casting after reheating. 1

It has been'discove'red that by the present invention'it is possible to produce in onev operation a manganese steel casting, nonannealed and non-quenched, which is characterized by great toughness, great ductility and'a uniformly fine and closely knit-crystalline structure, these desirable characteristics being possessed in an even greater de-' gree than they .are possessed by manganese steel castings produced by the processes heretoforeemployed. V r

In accordance with this invention the casting is made in a permanent mold with a matrix which yields the. desired form, so

that only a minimum of grinding or fluishing isrequired' The matrix of the mold is first filled'with molten inetalof such temperature that substantially allof the metal in the matrix will be at or above the melting point of the metal when the pouring is linisl'ied. Then the metal is cooled swiftly and uniformly so that the temperatures of at least the outer portions of the casting, that is, of all portions of the casting in contactwith theinold, will be practically the sameat any given instant. The swift cooling is continued past the various critical. points until the temperatures of all portions of the surface of the casting 'in contact with the.

is preferable to allow the casting to remaiir in the mold until the temperature of all portions of the-surface thereof is well below the crystallizing point, in order that the' creation of internal strains or stresses may be prevented absolutely and that the crystal.

line structure obtained when the cooling passed through the'upper critlcal polnt may be permanently fixed. The molten metal is I cooled swiftly to a point below the crystallizing point in order to prevent segregation of the various constituents of'the metal and "the formation of secondary or wealrening structures and is cooled. uniformly with rev lions;

has a.

mental structure" L .r'

' sucl'i'elefects have once ,i: th order to case-11155111 Woultl resultfrom 1' A LOllS diil'ereni; [rat-es of c olingiiidiiferent; 901* known the Zm'angenese o ill 13 steel gn/ oslup itsheut with gives up its heat reluctantly. Consequently it is necessary after the setting hastaken place to =avccelerate the radiation of heat from the ousti ig beyond the normal rat-e s 1 the desired. poolingas This result secured l which possesses not s tcondo A i In the ore v i" T isle to eiupi el as 'eteto'lore employee.

iron. which fed quickly,

iElOlO of enjother Lt w ofhiziteiizrlswhich conductivity and heat oi but it a P material or possesses the storage anol tear o;

By the term um-ngzmese steel, as employed heRimrefernce is had particularly to a StfifilWlLlClIQOIItQlZIS from 11 percent.v

to. 15 per cent. of manganese, huh-these w. limits, may be varied if:

ranges whi'o psi-"0" duotioto of a commeiei ventioii therejtore is not i nes'e steel of any phi elys iix The product of the onp ovecl process, not only possesses the characteristics above re- 5821 86. to but is freefr'om-the arious detri- "aims which often.

Jl in the usual moulty or impossibility some hy reheatiug 'lSSlbl'S' With-- clesi'aiecl within. the ssilole 501' the [prouct and the in exist" in 'casti her because 0 of i'GnlGVllig or c'ui'fin to tern erutuie 'Wll'l. out permaneu free from 'UTOClUCELl wfthe em moms to of producin P v in cooling manganese C ell which co the metal. 03. ing swiftlyfrom u ten'ipemture at or above eetrepid'ity while it 1s molten but that Lifter it sets t c hut it neat storage I greater than that usually possessed s it. is ieter so thatthe l y I .fll resist the wear pi cticol maybe employecl.-

fine 21ml closely lii 'inangane'se steel and clos this 1 the' ou'izei portions of the cast- 'ieee'eee the melting poiixt' of the metal to etempoxhtu e l elow the crystallizing g oint" of the metalgfz utl'then allowing the casting to cool. to normal 'afsmospheric. temperature.

producing castings vmlng enese steel, which'jconsists .111 pour the metal filo) el m'old which has relatively 1 large heat conducting ca,pzicity,'whereby the metal of the outer port-ions of the casting is brought swiftly from a tempetatura ator .above the melting. pointif to a, temperature below the c 'ystal'lizing point Without. "per-- mitting segregution'to occur, andthen allowing the .casting to coolto normal atmospheric temper atuie.

3; A, projcess of producing castings from mahganese steel; Which'consists in crystallizing the metal of the ,castiiig Without the formationof secondary 'and weakening.

'struoturesby swiftly drawing the heatfrom" the outer portions of the casting until the "temperature thereof is at or'below the crystal-lizing point, and then ,allow'ing the-cast ing to cool toatn'iospheric temperature.

4. A process of producing castings from manganese steel without quenching, such ca-stings having a uniformly fine crystalline structure throughout which consists in cooling the metal of the outer portions of the casting swiftly from a temperature at or above the melting point of the metal. by

pouring the metal into a mold which has it high conducting and: heat-storing capacity,-

causing-the casting to remain in the mold until the temperature of the outer portion thereof is at 01. below the crystallizing point of the metal,- ancl then removing the casting from then'iolcl and allowing the some to cool to nornial atmospheric temperature. 3

-5. A non-annealed and 11011(1U.811Cl1( manganese steel -custing which possesses toughness and due lily and has 21 uuiformlv irystzilline structure.- MA non-mine which possesses toughness anti Clue V I has a uniformly knit 'crystalliue structure and is tree from secondary structures and from lute 121 stifiihs This"specification signed and- .YllllOSriOLl dag of-Felwwzary, A. D. 191L EDGAR A. CUSTE R.

I v Signerlin the preseutzeof- JOSEPH M. H GHES,

"hucl nou-quenched