US856250A - High-manganese steel with low carbon. - Google Patents

Description

' nese steel in order to avoid cracks therein or I or when they are being heated preparatory to in carbon, that is, containing say less than ROBERT ABBOTT HADFIELD, OF SHEFFIELD, ENGLAND.

HIGH-MANGANESE STEEL WITH LOW CARBON.

Specification of Letters Patent.

Patented June 11,1907.

Application filed April 16, 1907. Serial No. 368,583.

To all whom it may concern.-

Be it known that I, ROBERT ABBOTT-HAD- FIELD, a subject of the King of Great Brit-v ain, and a resident of Sheffield, county of York, England, have invented an Improve-'- ment in High-Manganese Steel with Low Carbon, of which the following description, in connection with the accompanying drawing, is a specification, like letters on the draw-- in representing like parts.

In the manufacture of .high manganese steel, wherein the product is required to contain, say, from 10% to 14% and upward of. manganese it has not heretofore been found practicable, orindeed commercially ossible, to kee the percentage of carbon as ow as is desira le.

As a consequence of the comparatively and undesirably high percentage of carbon (owing to the common use of ordinary ferro-manganese, containing from 6% to 9% of carbon) and'because of the fact that manganese steel is a bad conductor of heat,- it results that great care has to be taken in treating castings and forgings made from such high manga-.

fracture thereof when they are being cooled,-

being subjected to a water toughening process, as well as during such processand thereafter. In the course of my studies and exeriments to overcome such objectionable features due to the high percentage of carbon in such steel I have discovered that by using, in the manufacture of steel of the character specified, an alloy of manganese and iron low 2% to 3% of carbon, instead of the ordinary ferro-manganese, I am enabled to produce a magnetic .high manganese steel in forms result is due to the fact that owing to the comparatively low percentage of carbon in the manganese steel made in accordance with my invention the steel is rendered much less liable to fracture during the cooling, or heating and cooling treatment for toughening it hereinbefore mentioned, and such steel is distinguished by its relatively strong magnetic character.

' A low carbon manganese-iron alloy suitable for use in the manufacture of high manganese steel in accordance with my present invention is that now produced in the electric furnace and which contains usually from to (seventy to ninety percent) of manganese with less than 2% to 3% (two to three percent) of carbon. 1 1: 5

In carrying out my invention low carbon manganese-iron alloy such as specified is added, referably in a molten condition, to a base 0 molten decarbonized iron, such as that used in the production of acid steel, and from which practically the whole of the carbon, silicon, and manganese have been eliminated in suitable manner, as for instance by the pneumatic or the open hearth method. The manganese alloy and the iron are preferably weighed in' molten condition to insure that the resulting manganese steel shall accurately contain the desired percentage of manganese. The manganese steel thus produced is then poured into molds to form castings, or into molds to form ingots which are forged in any suitable manner requisite for dealing with manganese steel. I

By the process described I am enabled to produce in a practical manner and on a commercial scale a manganese steel having a much lower ercenta e of carbon than heretofore, and w ch stee can therefore be easily and readily heated and cooled with much less liability to fracture than heretofore.

A further advantage resulting from my invention is'that articles can be safely made of much thicker sectionv of the improved manganese steel than of ordinary manganese 1 steel. Thus, owing to the difficulties hereinbefore mentioned, and to the fact that higher percentage of carbon in manganese steel as heretofore made tends to prevent as perfect or complete a toughening as is desirable, it has not heretofore beerf possible to produce on a practical scale, from high manganese steel, articles of more than about three or four inches in -thickness when the same reuired toughening. On the other hand artic es canbe made of the improved steel herein described of much thicker section while admitting of theirbeing properly toughened. The steel made in accordance with my prescut invention is characterized by its rela- 3 If desired the manganese steel inanufaclured in accordance with my invention may contain other elements than iron, manganese and carbon, as for example, it may contain nickel, chromium, tungsten, molybdenum and vanadium in varying proportions, say from one-tenth of one percent to thirty per cent (1% to 30%).

Having fully described my invention, What I claim as new and desire to secure by Letters Patent is: I

1. The herein-described steel containing] less than 1.0% of carbon and/from 10% to 14% of manganese, capable of being reai'lily heet-treated and toughened in the mass with- I out cracking, andilistinguished by its relatively strong magnetic character.

2. The herein-described steel containing less than 1.0 of carbon and a high percentage of manganese, distinguished by its relatively strong magnetic character, and cnpable of being readily heat-treated and tfliiglh ened in the mass without cracking.

In testimony whereof, [have signed my name to this specification, in the presence of two subscribing witnesses. V

ROBERT ABBOTT IIA DFIELI).

Witnesses:

PERCY PHILLIPEPS, 'ALFR n NUT'rmo.