# US 4,396,440 A · Crushing bodies forged from steel

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- Number: US 4,396,440 A
- Document ID: US4396440A
- Status: Granted
- Kind: A
- Application number: 06/300,739
- Filed: 1981-09-10
- Granted: 1983-08-02
- Earliest claimed: 1978-07-11
- Assignees: Acieries Thome Cromback
- Inventors: Michel Thome
- Web page: https://patentgrep.com/patent/US4396440A

## CPC

- C22C 38/18: containing chromium
- B02C 17/20: Disintegrating members
- C22C 38/36: with more than 1.7% by weight of carbon
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- B02C: CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN ({household tools and machines for pulverising foodstuffs, e.g. coffee and spice mills A47J42/00; pharmaceutical mortars A61J3/02; mechanical processing of refuse and garbage B03B9/06; dressing mould materials by grinding B22C5/04}; obtaining metallic powder by crushing, grinding or milling B22F9/04; {recovery of plastics by disintegrating B29B17/00; crushing raw materials in starch making C08B30/02; beaters for papermaking D21D1/02; crushing devices specially for transport in mines E21F13/002; slag crushing devices F23J1/00; fuel milling devices in combustion apparatus F23K1/00; household devices for crushing coal F24B15/02; ice disintegrating devices F25C5/02})

## Abstract

The invention relates to crushing bodies forged from steel having a high carbon content and a finely divided martensitic structure throughout, comprising a carbide content of 2 to 6% by weight, in the form of mixed iron and chromium carbides of the (Fe, Cr).sub.3 C type. The process for manufacturing these crushing bodies consists in bringing up to a temperature of the order of 900.degree. to 1100.degree. C. a bar or billets of cast or moulded steel and having the desired composition, said bar is possibly cut into billets at said temperature, and said billets are forged at said temperature of 900.degree. to 1100.degree. C. These crushing bodies allow the crushing of very abrasive materials, for a limited cost.

## Claims

### Claim 1

Finished industrial products comprising crushing bodies, for crushing abrasive materials, forged from steel having a high carbon content and a finely divided martensitic structure throughout, said forged steel being non-graphitic and said bodies having no graphitic carbon content therein, and said bodies comprising 1.7 to 2% carbon and 0 to 2% chromium, in percentage by weight; a carbide content of 2 to 6% by weight, in the form of mixed iron and chromium carbides of the (Fe,Cr).sub.3 C type.

### Claim 2 (depends on 1)

Crushing bodies are defined in claim 1, when said bodies comprise, in percentage by weight, 0.5 to 2% silicon, 0 to 1% copper, and 0.5 to 2% manganese.

### Claim 3 (depends on 1, 2)

Crushing bodies as defined in claims 1 or 2, said bodies comprising traces of special elements such as boron, titanium or niobium.

### Claim 4 (depends on 1, 2)

Crushing bodies as defined in claims 1 or 2, said bodies having a 7000/mm.sup.2 carbides therein comprising a carbide content of approximately 6% by weight and having a hardness of 500 to 650 HB.