EP0052584A1
Expired / Lapsed
EP
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A method of producing a steel body comprising hard material inserts
Assignee: Institut Cerac SA
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Filing: 1981-10-19
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Granted: —
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Expires: 2001-10-19
Abstract
Abstract A method of producing a steel body (1) comprising hard material inserts, (2) particularly a drill bit for rock drilling, in which steel powder is compacted at least partially around the inserts from a cold state to a high density preform. The preform is then sintered and because of the choice of alloy the steel powder shrinks substantially during the sintering. A high strength drill bit is produced in which the inserts may have almost any form, in particular a form optimized for a particular application.
Inventors
- 👤 Raybould Derek
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 20:08
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/56; B; B22; B22F; B22F7/00; B22F7/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
A method of producing a steel body comprising hard material inserts in which preformed hard material inserts are placed in a die in a desired pattern, steel powder is added to at least parti - ally surround the inserts and the powder is compacted, characterized there by that the steel powder is compacted from a cold state to a high density preform, that said preform is subsequently sintered, whereby for said steel powder is chosen a steel alloy which undergoes substantial shrinkage during the sintering to produce a firm fixation of the hard material inserts in the steel body.
Claim 2
Independent Claim
99 words
A method of producing a steel body comprising hard material inserts in which preformed hard material inserts are placed in a die in a desired pattern, steel powder is added to at least parti - ally surround the inserts and the powder is compacted, characterized there by that the steel powder is compacted from a cold state to a high density preform, that said preform is subsequently sintered, whereby for said steel powder is chosen a steel alloy which undergoes substantial shrinkage during the sintering to produce a firm fixation of the hard material inserts in the steel body.
Claim 3
Dependent Claim
24 words
A method according to claim 1, characterized there by that the steel powder is impacted by a high velocity punch to effect said compaction.
Claim 4
Dependent Claim
17 words
A method according to claim 1 or 2, characterized there by that said sintering comprises sinter forging.
Claim 5
Independent Claim
34 words
A method according to any of the preceding claims, characterized there by that the steel powder is compacted around irregularities on the hard material inserts to mechanically lock the inserts in the steel body.
Claim 6
Independent Claim
56 words
A method according to any of the preceding claims, characterized there by that said hard material inserts comprise a part having a larger cross-sectional area than the cross -sectional area at the surface of said steel body and that the steel powder is compacted around said part to mechanically lock the inserts in the steel body.
Claim 7
Independent Claim
32 words
A method according to any of the preceding claims, characterized there by that a steel powder comprising 4-16 % Ni, 0.25-1.5 % Cu, 0.2-0.5 Z Mo and 0.3-0.9 % C is used.
Claim 8
Independent Claim
34 words
A method according to any of the preceding claims, characterized there by that a layer of metal is metallurgically bonded, first to the hard material inserts and then during the sintering to the steel.
Claim 9
Independent Claim
28 words
A method according to any of the preceding claims, characterized there by that the steel powder has varying composition whereby a sub-surface layer of lower hardness is obtained.
Claim 10
Independent Claim
28 words
A method according to any of the preceding claims, characterized there by that the hard material inserts comprise hard metal discs having a surface layer of sintered diamonds.
References Cited (Backward Citations)
GB530639A
Cited
US3673676A
Cited
US3837068A
Cited
US4164527A
Cited
FR2384574A1
Cited
GB2017153A
Cited
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