US140673A

US140673A - Improvement in the manufacture of steel for boiler-plates

Info

Publication number: US140673A
Authority: US
Publication date: 1873-07-08
Anticipated expiration: 1890-07-08

Description

UNITED STATES PATENT OFFIon.

OGDEN BOLTON, J OF OHARTIERS TOWNSHIP, AND JOHN PEDDER, or

' r IITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN THE MANUFACTURE OF'STEEL FOR BOILER-PLATES, &c.

Specification forming part of Letters PateiitNo. 40,673, dated July 8, 1873; application filed April 12, 1873.

To all whom it may concern:

Be itknown that we, OGDEN BOLTON, Jr., of Ohartierstownship, andJOHNPEDDER, ofPittsburg, in the county of Allegheny and State'of Pennsylvania, have invented a new and useful Improvement in the Manufacture of Boiler- Plate Steel and we do hereby declare the following to be a full, clear, and exact description thereof.

Our invention consists in the manufacture of homogeneous boiler-plate steel, of a uniformly low quality, by subjecting a hard or high steel plate or ingot to the process of decarbonization, by the use of suitable known decarbonizing agents, at less than a melting temperatiire.

To enable others skilled in the art to make use of our improvement, we will proceed to describe its manner of operation and use.

i In the manufacture of homogeneous boilerplate steel it has been found that however carefully the work is carried on all the plates will not be of uniform quality, andvhence the harder plates have to be thrown out, with a consequent loss or, if, as is commonly the case, they are worked in the danger of disaster from explosion or excessive pressure is thereby materially increased. By our process any such plates, which are found to be too hard, are readily decarbonized till they are brought to the desired standard, and then they are worked in without loss or danger. Also, it is well'known that in making such boiler-plates of steel on a large scale the pouring of soft steel such as is required, is attended, with considerable risk of waste and loss. If the steel be made a little harder such risk is largely obviated, but the steel is then too hard for boiler-plate. By our process we,

make the boiler-plate hard, and then decarbonize it to such degree that it'shall be equal to-the best boiler-plate made, and of the same uniform quality; and such decarbonizing process we perform on the ingots themselves, or on the worked steel at any desired subsequent stage in its manufacture. The steel to be decarbonized is inclosed in a suitable box, case, retort, or furnace, and is covered on all sides, either in separate blocks or sheets, or in alternate layers, with any known suitable oxidizing agents or substances capable of evolving, when heated, oxygen, chlorine, or fluorine, or other gases which will combine with the carbon of the steel; or such gases may be generated in a separate retort and conveyed directly to, and brought into close contact with, the steel to be decarbonized. While subjected to this process the steel is to be heated to any desired temperature, but preferably to about a cherry-red heat. The 'process is carried on in about the manner adopted in the cementation process, and for about the same length of time, varying with the thickness of the plate, the amouni of the reduction desired, the temperature employed, &c., the effect of which conditions, as

efiecting the result, are within the knowledge of the skilled workman, and need not be stated The utility of the process is alsov in detail. obvious- The plates, when brought to a uniformly low quality, are removed and worked up in the usual way.

The conditions under which the ophration above described can be successfully carried on will vary considerably, as in other kindred operations, but for the general purposes we believe the following to be best: 1 We employ steel containing; from to .4 (three-tenths to four-tenths) pergcent. of carbon, as this is the" easiest to run forour purpose, and bring the same to ingot or plate form to a thickness of about one inch. Such plates, when embedded in or surrounded by metallic or other suitable oxide, in any suitable known heating-furnace such, for example, as is used in-the cementation process-is kept at about a cherrywred heat for from one and a half to two days, by which they will be brought to the condition desired. With every increase of, say, .1 (onetenth) per cent. of carbon in the steel the decarbonizing operation should be continued about or a little more than half a day longer.

The plates produced by the process above set forth will come under the headot homogeneous boiler-plate steel, though theprocess may be arrested before the same degree of decarbonization is carried to the center as exits at the surface. For practical purposes it will be homogeneous, and such plates are so recognized in the art. 7

Whatwe claim as our inventlon to secure by Letters Patent, is-

- The manufacture of homogeneous boiler- In testimony whereof we, the said OGDEN BOLTON, J r., of Ghartiers township, and JOHN ,and desire PEDDER, have hereunto set our hands.

' OGDEN BOLTON, JR.

JOHN PEDDER.

plate steel-by bringing a hard or high steel to a uniformly low grade, through the agency of deca-rbonizing agents brought to bear on the same after pouring, and while in an unmelted state, substantially in the manner Witnesses: v or A. S NICHOLSON, G. H. CHRISTY.

set forth.