US1466636A - Treatment of manganese-steel castings - Google Patents

Description

Patented mg. 28, 1923.

TENT QFFICE.

' STANLEY AIEG AND GEORGE E. HANKS, OF HIGH BRIDGE, NEW JERSEY, ASSIGNORS TO TAYLOR-WHAR'ION IRON AND STEEL COMPANY, OF HIGH BRIDGE, NEW JER- SEE", A CORPORATION OF NEW JERSEY.

rnm'rmnnr "or MANGANESE-STEEL cAs'rINGs.

No Drawing.

To all whom it may concern:

Be it known that we, STANLEY APGAR and GEORGE R. HANKS, citizens of the United States, residing at High Bridge, in the county of. Hunterdon and State of New Jersey, have invented certain new and useful Improvements in the Treatment of Manganese-Steel Castingsi of which the following is a specification.

The object of our invention is to provide a dependable method of heat treatin manganese steel castings of large size an intricate section. We are aware of the method proposed by Brinton in his patent 812,811, and also of the Hadfield method. Brintons method was undoubtedly an advance over the Hadfield practice, and he refers to the successful heat treatmentof castings weighing up to eight tons. But present day operations are of greater magnitude, and the Brinton method is not dependable with castings weighing thirteen to twenty tons and up wards'and embodying sections of large surface area compared totheir volume.

ln practicing our invention, the castin is permitted to remain in the mould until 1t can be handled without bending, whereupon it is removed and the large surface areas which disperse the heat rapidly are enveloped in a sand blanket. Thus protected, the casting is placed in a furnace which has been previously brought to'a temperature of about 500- C. The furnace is immediately sealed and held without firing in order to establish an even temperature of the furnace and casting. We maintain accurate pyrometer control, and when the reading indicates an even temperature we disperse the 40 heat slowly and uniformly, and, at asafe point, remove the sand blanket.

L The castin denuded of sand is then heated slowly' an uniformly, to the usual temperaturefor. the treatment of manganese 5 steel, and is then quenched in water.

By our method of procedure we avoid the setting up ofi dangerous shrinkage stresses such as are prevalent when the castings are cooled below a red heat and during the,

heatin up of the castings from, the minitem vApplication filed June 5, 1922. Serial No. 566,139.

which consists 1n blanketing the casting as soon as it can be handled without bending, and while so protected introducing it into a furnace previously heated to an annealing temperature, sealing the furnace and controlling the heat so as to bring the furnace and casing to an even temperature, reducing the temperature slowly and uniformly to a predetermined point, removing the blanket, and reheating slowly-and uniformly-to the usual temperature for the treatment of manganese steel, and then quenching in water;

:2. The method of treatin manganese steel castings of large size and intricate form, which consists in sand protecting excessive heat dispersing sections-as soon as the castm can be handled without bending, and .wfiile so protected introducing the casting into a furnace heated to about 500 (3;, sealing the furnace and holding it without fir-' ing until the furnace and-the casting are at an even temperature, permitting the temperature to decline slowly and uniformly to a predetermined point, removing the sand raising the temperature at a slow and regulated rate to the usual temperature for the treatment of manganese steel, and rapidl quenching. I

- 3. Tile method of treating manganese steel castings of large size and intricate form, which consists in charging the casting, while hot from the casting heat, into a furnace heated to an annealing temperature,

maintaining proper control-t0 establish an even temperature of the furnace and casting,

gradually reducing the temperature to a predetermined oint, and then slowly and uniformly heatmg the, casting .to the usual rature for thetreatmentof manganese stee and quenching, In testimony whereof we aifix-our signatures. STANLEY APGAR. GEORGE R: HANKS.