EP1458517A2 - Vermicular cast iron of high machinability - Google Patents
Vermicular cast iron of high machinabilityInfo
- Publication number
- EP1458517A2 EP1458517A2 EP02782549A EP02782549A EP1458517A2 EP 1458517 A2 EP1458517 A2 EP 1458517A2 EP 02782549 A EP02782549 A EP 02782549A EP 02782549 A EP02782549 A EP 02782549A EP 1458517 A2 EP1458517 A2 EP 1458517A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- cast iron
- machinability
- vermicular cast
- vermicular
- content
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
- C22C37/10—Cast-iron alloys containing aluminium or silicon
Definitions
- the present report is about vermicular cast iron of high machinability, and more specifically, to a vermicular cast iron that presents a bigger amount of graphite in its microstructure.
- the vermicular cast iron comprises a group of Fe-C-Si alloys and also contains Mn, P, S, with controlled additions of Mg, presenting graphite predominately in vermicular form (form IV according to Standard ASTM A247), with up to 20% of nodules (forms I and II Standard ASTM A247) in its microstructure .
- its ultimate tensile strength may be changed from 350 to 500 Mega Pascal through complementary additions of pearlitic elements such as Mn, Cr, Cu and Sn.
- the vermicular cast iron has been increasingly applied in automotive components such as internal combustion engine blocks, internal combustion engine heads, disks and brake drums.
- the low machinability of conventional vermicular cast iron is a characteristic known to the material which reflects in the decrease of a tool life when compared to the machining of gray cast iron.
- the decrease in the tool or component life is real and effective, being its quantitative parameter dependent on the machining operation in particular. It can be observed that such reduction is of at least 50% in milling and boring operations, and could decrease up to 95% the life of the tool in cylinder hole reaming operations.
- One of the goals of the present invention is to provide vermicular cast iron of high machinability, that allows an increase in the life of tools to be used with the cast part together with the innovated characteristics.
- Another goal of the present invention is to provide vermicular cast iron of high machinability that presents a machinability at least 40% bigger than the conventional vermicular cast iron, machinability evaluated by the life of the cutting tool.
- vermicular cast iron of high machinability that comprises the inclusion of a defined amount of graphite in its microstructure and in the limitation of harmful chemical elements, besides defining the parameters for the correct pearlite interlamellar spacing.
- the ideal amount of graphite in the microstructure is between 10 and 13%.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Powder Metallurgy (AREA)
- Cutting Tools, Boring Holders, And Turrets (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Vermicular cast iron of high machinability free from microporosities, comprises classes between 350 and 500 MEGA PASCAL of ultimate tensile strength, presenting machinability at least 40 % bigger than that of conventional vermicular cast iron; the machinability being evaluated by the life of the cutting tool.
Description
'VERMICULAR CAST IRON OF HIGH MACHINABILITY"
The present report is about vermicular cast iron of high machinability, and more specifically, to a vermicular cast iron that presents a bigger amount of graphite in its microstructure.
As known to experts in the area, the vermicular cast iron comprises a group of Fe-C-Si alloys and also contains Mn, P, S, with controlled additions of Mg, presenting graphite predominately in vermicular form (form IV according to Standard ASTM A247), with up to 20% of nodules (forms I and II Standard ASTM A247) in its microstructure .
To obtain the desired class of that iron alloy, its ultimate tensile strength may be changed from 350 to 500 Mega Pascal through complementary additions of pearlitic elements such as Mn, Cr, Cu and Sn.
The vermicular cast iron has been increasingly applied in automotive components such as internal combustion engine blocks, internal combustion engine heads, disks and brake drums.
When applied to automotive components, additions of Ti may be done to increase the resistance to wear out and to improve the lubrication of the cylinder in engine blocks. To be applied in components of the automotive line, the substitution of gray cast iron by vermicular cast iron is usually done to increase the tensile strength of the said components. This substitution, however, brings some
manufacturing problems not yet entirely solved.
One of these problems is the low machinability of the vermicular cast iron when compared to the gray cast iron. The low machinability of conventional vermicular cast iron is a characteristic known to the material which reflects in the decrease of a tool life when compared to the machining of gray cast iron.
The decrease in the tool or component life is real and effective, being its quantitative parameter dependent on the machining operation in particular. It can be observed that such reduction is of at least 50% in milling and boring operations, and could decrease up to 95% the life of the tool in cylinder hole reaming operations. One of the goals of the present invention is to provide vermicular cast iron of high machinability, that allows an increase in the life of tools to be used with the cast part together with the innovated characteristics.
Another goal of the present invention is to provide vermicular cast iron of high machinability that presents a machinability at least 40% bigger than the conventional vermicular cast iron, machinability evaluated by the life of the cutting tool.
This and other goals and advantages of the present invention are achieved with vermicular cast iron of high machinability that comprises the inclusion of a defined amount of graphite in its microstructure and in the limitation of harmful chemical elements, besides defining
the parameters for the correct pearlite interlamellar spacing.
With the definition of the correct amount of graphite in the vermicular cast iron, it is possible to incorporate an important microstructural aspect as the graphite acts as a lubricant to the cutting tool, thus maximizing its life.
While the amount of graphite varies from 8 to 11% (in volume) in the conventional vermicular cast iron, in the vermicular cast iron of high machinability, object of this invention, the ideal amount of graphite in the microstructure is between 10 and 13%.
This range of graphite percentage quantification is obtained through the adequate dimensioning of the contents of Carbon and Silicon, which shall be between 3,5 and 3,8% for C and between 2,0 and 2,6% for Si.
An even better improvement in the machinability of the vermicular cast iron is obtained, if compared to the conventional vermicular iron, when elements that form carbide or carbonitrides (Cr, Mn, Ti ) are limited.
With the limitation of the content of Chromium to a maximum of 0,050%, of the content of Manganese to a maximum of 0,40% and of the content of Titanium to a maximum of 0,015%, it is possible to obtain an effective machinability of the component or part conceived by the vermicular cast iron. It is important to mention that those limitations are only achieved, in practice, with the use of metallic raw materials of high purity.
In addition, the machinability of the vermicular cast iron is improved with the formation of pearlite of lamellar spacing bigger than 0,5 microns, which is obtained under controlled conditions of part cooling at a temperature ranging between 800° and 650°C.
The machinability advantages previously mentioned are thus increased.
Despite the fact that a preferred constructive concept has been described and illustrated, it is important to mention that changes are feasible and possible to be carried out without deviating from the scope of the present invention.
Claims
Claims
1- 'VERMICULAR CAST IRON OF HIGH MACHINABILITY" free from microporosities, comprising classes between 350 and 500 MEGA PASCAL of ultimate tensile strength, characterized by presenting a machinability at least 40% bigger than the conventional vermicular cast iron, the machinability being evaluated by the life of the cutting tool.
2- 'VERMICULAR CAST IRON OF HIGH MACHINABILITY", as per claim 1, characterized by presenting around 10 to 13% of graphite in its microstructure, being that graphite predominately vermicular, with 0 to 20% of nodules and absence of lamellar graphite.
3- 'VERMICULAR CAST IRON OF HIGH MACHINABILITY", as per claim 2, characterized by the fact that the metallic matrix microstructure is comprised of ferrite and pearlite, proportion of 50 to 100% pearlite, according to class (350 to 500 Mega Pascal) , and the pearlite presenting a minimum interlamellar spacing of around 0,5 microns in a section thickness of 5mm.
4- 'VERMICULAR CAST IRON OF HIGH MACHINABILITY", as per claim 1, or 2, or 3, characterized by presenting a content of Carbon between 3,5 and 3,8%, a content of Si between 2,0 and 2,6%, a content of Cr lower than 0,05%, a content of Mn lower than 0,40% and a content of Ti lower than 0,015 %.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BR0105987 | 2001-11-27 | ||
BR0105987A BR0105987B1 (en) | 2001-11-27 | 2001-11-27 | high machinable vermicular cast iron. |
PCT/BR2002/000164 WO2003045625A2 (en) | 2001-11-27 | 2002-11-26 | Vermicular cast iron of high machinability |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1458517A2 true EP1458517A2 (en) | 2004-09-22 |
EP1458517A4 EP1458517A4 (en) | 2005-02-23 |
Family
ID=3948158
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP02782549A Withdrawn EP1458517A4 (en) | 2001-11-27 | 2002-11-26 | Vermicular cast iron of high machinability |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP1458517A4 (en) |
BR (1) | BR0105987B1 (en) |
WO (1) | WO2003045625A2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101605905B1 (en) * | 2009-12-22 | 2016-03-23 | 두산인프라코어 주식회사 | Cgi cast iron and preparation method thereof |
BR102016021139B1 (en) * | 2016-09-13 | 2021-11-30 | Tupy S.A. | VERMICULAR CAST IRON ALLOY AND INTERNAL COMBUSTION ENGINE HEAD |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1069058A (en) * | 1965-05-04 | 1967-05-17 | Int Nickel Ltd | Cast iron |
US4409028A (en) * | 1979-10-24 | 1983-10-11 | Moore William H | Process for producing cast iron |
JPH04128340A (en) * | 1990-09-19 | 1992-04-28 | Hitachi Ltd | Compact vermicular graphite cast iron and sheave for elevator using the same |
EP0769615A1 (en) * | 1995-10-17 | 1997-04-23 | Ford Motor Company Limited | Engine cylinder block |
JPH09202935A (en) * | 1996-11-15 | 1997-08-05 | Hitachi Ltd | Compacted vermicular graphite cast iron and sliding device using the same |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6036754A (en) * | 1983-08-08 | 1985-02-25 | Kubota Ltd | Composite cylinder liner |
CN85107725B (en) * | 1985-10-17 | 1987-12-23 | 陕西机械学院 | Creeping graphite cast iron for manufacturing mould for glass bottle |
DE19654893C2 (en) * | 1996-07-25 | 1999-06-10 | Federal Mogul Burscheid Gmbh | Piston rings of internal combustion engines made of a cast iron alloy |
US5858127A (en) * | 1996-08-02 | 1999-01-12 | Gunite Corporation | Metal alloys and brake drums made from such alloys |
SE9904257D0 (en) * | 1999-11-23 | 1999-11-23 | Sintercast Ab | New cast iron alloy |
-
2001
- 2001-11-27 BR BR0105987A patent/BR0105987B1/en not_active IP Right Cessation
-
2002
- 2002-11-26 WO PCT/BR2002/000164 patent/WO2003045625A2/en not_active Application Discontinuation
- 2002-11-26 EP EP02782549A patent/EP1458517A4/en not_active Withdrawn
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1069058A (en) * | 1965-05-04 | 1967-05-17 | Int Nickel Ltd | Cast iron |
US4409028A (en) * | 1979-10-24 | 1983-10-11 | Moore William H | Process for producing cast iron |
JPH04128340A (en) * | 1990-09-19 | 1992-04-28 | Hitachi Ltd | Compact vermicular graphite cast iron and sheave for elevator using the same |
EP0769615A1 (en) * | 1995-10-17 | 1997-04-23 | Ford Motor Company Limited | Engine cylinder block |
JPH09202935A (en) * | 1996-11-15 | 1997-08-05 | Hitachi Ltd | Compacted vermicular graphite cast iron and sliding device using the same |
Non-Patent Citations (2)
Title |
---|
ROHRIG, K.: "Cast Iron With Vermicular Graphite-Processing, Properties, Applications.ÄGusseisen mit Vermiculargraphit - Herstellung , Eigenschaften, Anwendung .Ü." KONSTRUIEREN & GIESSEN 16, (1), 7-27, PHOTOMICROGRAPHS, GRAPHS, 29 REF. ISSN: 0341-6615, 1991, XP009041753 * |
See also references of WO03045625A2 * |
Also Published As
Publication number | Publication date |
---|---|
WO2003045625A3 (en) | 2003-10-23 |
BR0105987A (en) | 2002-11-12 |
BR0105987B1 (en) | 2009-08-11 |
EP1458517A4 (en) | 2005-02-23 |
WO2003045625A2 (en) | 2003-06-05 |
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Legal Events
Date | Code | Title | Description |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
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17P | Request for examination filed |
Effective date: 20040614 |
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AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR |
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A4 | Supplementary search report drawn up and despatched |
Effective date: 20050111 |
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RIC1 | Information provided on ipc code assigned before grant |
Ipc: 7C 22C 37/00 A |
|
17Q | First examination report despatched |
Effective date: 20050317 |
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STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
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18D | Application deemed to be withdrawn |
Effective date: 20050728 |