CA1042237A - Grey cast iron - Google Patents
Grey cast ironInfo
- Publication number
- CA1042237A CA1042237A CA223,182A CA223182A CA1042237A CA 1042237 A CA1042237 A CA 1042237A CA 223182 A CA223182 A CA 223182A CA 1042237 A CA1042237 A CA 1042237A
- Authority
- CA
- Canada
- Prior art keywords
- cast iron
- inoculating
- alloy
- grey cast
- iron
- 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.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/08—Manufacture of cast-iron
Abstract
ABSTRACT OF THE DISCLOSURE
This invention relates to a grey aluminium cast iron with lamellar graphite, high mechanical strength and low ledeburitic hardening, which cornprises 2 to 4% C, 0 to 1% Si, 1 to 3% Al, 0 to 0.7% Mn, 0 to 0.05% S,and 0 to 0.1% P, and inoculated with 0,3 to 2% inoculating alloy which contains from 20 to 70% rare earths. The cast iron alloy may be economically produced in an industrial scale.
This invention relates to a grey aluminium cast iron with lamellar graphite, high mechanical strength and low ledeburitic hardening, which cornprises 2 to 4% C, 0 to 1% Si, 1 to 3% Al, 0 to 0.7% Mn, 0 to 0.05% S,and 0 to 0.1% P, and inoculated with 0,3 to 2% inoculating alloy which contains from 20 to 70% rare earths. The cast iron alloy may be economically produced in an industrial scale.
Description
'~ L0~ '7 -~ This invention relates to a grey cast iron with lamellar graphite, hlgh mechanical strength and low ledeburitic hardening, which comprises,:in weight per cent:
2 to 4% C
' o to 1% Si 1 to 3% Al 0 to 0.7/0 Mn - 0 to 0~05% S
: 0 to 0.1% P
:. ' and inoculated with 0.3 to 2% inoculating alloy.
A cast iron of such type has been disclosed in , Belgian Patent 710,679 in the name of the Applicant.
.
According to said previous patent, the inocu- -lating alloy comprises as active inoeulating element, an ele-ment chosen in the group comprised of Ca, Ba, Sr.
A first drawback of calcium alloys lies in .
such alloys causing the formation of a large amount of reac-tion slag. Said slag remains ln suspension in the liquid iron and due to the density difference rises slowly to the bath surface. It is consequently required to slag-off the bath before the casting but even after such slagging, s~g forms again on the surface. It is impossible to wait long enough to slag-off completely the cast iron, as such iron cools too much in the ladle. There results therefrom that some slag is always taken along inside the mold during the cas-ting operation. To avoid slag entering the part, slag traps have to be provided inside the casting channel, which makes the casting system intricate.
A second drawback of the calcium alloys lies .
,~ ' - 1 - ~ '' ~ .
.
' o to 1% Si 1 to 3% Al 0 to 0.7/0 Mn - 0 to 0~05% S
: 0 to 0.1% P
:. ' and inoculated with 0.3 to 2% inoculating alloy.
A cast iron of such type has been disclosed in , Belgian Patent 710,679 in the name of the Applicant.
.
According to said previous patent, the inocu- -lating alloy comprises as active inoeulating element, an ele-ment chosen in the group comprised of Ca, Ba, Sr.
A first drawback of calcium alloys lies in .
such alloys causing the formation of a large amount of reac-tion slag. Said slag remains ln suspension in the liquid iron and due to the density difference rises slowly to the bath surface. It is consequently required to slag-off the bath before the casting but even after such slagging, s~g forms again on the surface. It is impossible to wait long enough to slag-off completely the cast iron, as such iron cools too much in the ladle. There results therefrom that some slag is always taken along inside the mold during the cas-ting operation. To avoid slag entering the part, slag traps have to be provided inside the casting channel, which makes the casting system intricate.
A second drawback of the calcium alloys lies .
,~ ' - 1 - ~ '' ~ .
.
3'~
in the usual industrial alloys haviny too much silicon~ Now the cast iron to which pertains this invention, which has for features a high mechanical strength and a low hardness, should have after inoculatio%n, a silicon content lower than 1% and preferably than~5~.
, . . .
-~. This silicon limitation causes problems by the ~::
, industrial manufacture where there should be reckoned with : :: , ., the accumulation of the silicon content in the batches due to the use of returns. ;
Indeed assuming that the scrap contains a%
.j :,, i of silicon and the inoculating medium ~/~ of silicon, when ~ inoculating with 1% of the alloy, the silicon content for ,~ the first melting will be :
~, a + xO
; :
When using r% of returns, the second batch . . .
, will be comprised of : (100 - r) scrap and r returns.
~he silicon amount in the second melting is : `
a. 100-r + r (a + x ) + x = a + (1 + r ) x , 100 100 100 100 100 100 By going further along these lines, one finds ~or the nth melting a silicon content equal to :
a + (1 + r + r2 + ,,, r ) x 100 100 100 loo ..
.. , , ,.. ~
`~ When going to the infinite, the relation ~
:, tends towards :
a ~100 100 (1) By taking :. ,. ~: .
r = 40h a = 0.3% (normal Si content in steel scrap) x = 66% (in the case of SiCa which is the usual inoculating `
'~, ; - 2 -.
: ' -- -- , .. ,.. ~ . .. .. ..
3'7 .;, alloy in the industry), it is found that the limit silicon content will be equal to 1~4~/
: . , The use of SiCa is thus substantially exclu-ded ~or the industrial production of aluminum cast iron.
From formula (1) there is derived that the limit silicon content in the cast iron will remain lower than 0.75% if the silicon content in the inoculating medium is not higher than 27%. Now there is no industrial alloy that contains enough ~; 10 calcium with a silicon content lower than 27%.
~`' For the industrial production of aluminum , cast irons, there has been produced a special alloy with the following composition : 3~/0 Fe, 15% Ca, 25% Si, 3~/0 Al.
As this alloy is not produced in large amounts J .
the manufacturing cost is very high, about 60 Belgian francs per pound.
In the previous patent in the name of the ; Applicant, there has been disclosed an inoculating alloy the ,; .
composition of which (Fe~lCa) is free from Si ; it is howe-ver an alloy obtained in the laboratory, the industrial production of which cannot be considered due to the prohibi-tive cost of removing Si.
This invention has for object to obviate the ; drawbacks due to the inoculating alloys disclosed in the first patent in the name of the ~pplicant, by providing ano-ther type of inoculating alloys whlch allow to make the cas-ting easier and to reduce the cost of manufacturing the alloy.
For this purpose according to the invention, the inoculating alloy contains as active inoculating element from S to 75% ra- -30- , :
in the usual industrial alloys haviny too much silicon~ Now the cast iron to which pertains this invention, which has for features a high mechanical strength and a low hardness, should have after inoculatio%n, a silicon content lower than 1% and preferably than~5~.
, . . .
-~. This silicon limitation causes problems by the ~::
, industrial manufacture where there should be reckoned with : :: , ., the accumulation of the silicon content in the batches due to the use of returns. ;
Indeed assuming that the scrap contains a%
.j :,, i of silicon and the inoculating medium ~/~ of silicon, when ~ inoculating with 1% of the alloy, the silicon content for ,~ the first melting will be :
~, a + xO
; :
When using r% of returns, the second batch . . .
, will be comprised of : (100 - r) scrap and r returns.
~he silicon amount in the second melting is : `
a. 100-r + r (a + x ) + x = a + (1 + r ) x , 100 100 100 100 100 100 By going further along these lines, one finds ~or the nth melting a silicon content equal to :
a + (1 + r + r2 + ,,, r ) x 100 100 100 loo ..
.. , , ,.. ~
`~ When going to the infinite, the relation ~
:, tends towards :
a ~100 100 (1) By taking :. ,. ~: .
r = 40h a = 0.3% (normal Si content in steel scrap) x = 66% (in the case of SiCa which is the usual inoculating `
'~, ; - 2 -.
: ' -- -- , .. ,.. ~ . .. .. ..
3'7 .;, alloy in the industry), it is found that the limit silicon content will be equal to 1~4~/
: . , The use of SiCa is thus substantially exclu-ded ~or the industrial production of aluminum cast iron.
From formula (1) there is derived that the limit silicon content in the cast iron will remain lower than 0.75% if the silicon content in the inoculating medium is not higher than 27%. Now there is no industrial alloy that contains enough ~; 10 calcium with a silicon content lower than 27%.
~`' For the industrial production of aluminum , cast irons, there has been produced a special alloy with the following composition : 3~/0 Fe, 15% Ca, 25% Si, 3~/0 Al.
As this alloy is not produced in large amounts J .
the manufacturing cost is very high, about 60 Belgian francs per pound.
In the previous patent in the name of the ; Applicant, there has been disclosed an inoculating alloy the ,; .
composition of which (Fe~lCa) is free from Si ; it is howe-ver an alloy obtained in the laboratory, the industrial production of which cannot be considered due to the prohibi-tive cost of removing Si.
This invention has for object to obviate the ; drawbacks due to the inoculating alloys disclosed in the first patent in the name of the ~pplicant, by providing ano-ther type of inoculating alloys whlch allow to make the cas-ting easier and to reduce the cost of manufacturing the alloy.
For this purpose according to the invention, the inoculating alloy contains as active inoculating element from S to 75% ra- -30- , :
4,~37 re earths.
In a preferred embodiment of the invention, the inoculating alloy contains from 20 to 7~/0 rare earths.
::'1 ' , .
; The active inoculating medium is comprised o one or more generally several rare earths (TR) as the man of the art knows. Usually the active inoculating medium is comprised of an alloy which is well known under the name of misch metal, which contains about 5~/0 Cerium and about
In a preferred embodiment of the invention, the inoculating alloy contains from 20 to 7~/0 rare earths.
::'1 ' , .
; The active inoculating medium is comprised o one or more generally several rare earths (TR) as the man of the art knows. Usually the active inoculating medium is comprised of an alloy which is well known under the name of misch metal, which contains about 5~/0 Cerium and about
5~/0 other rare earths such as lanthanum, neodymium and pra-~ :~
10seodymium.
It is significant to demonstrate the impor-tance o~ this invention, to mention as disclosed in an arti-, . , cle by Dawson in BCIRA Journal of Research 1961, vol. 9, ~ -p.l99, fig. 7, that an addition of more than 0.1 % misch me-tal to silicon cast iron, which corresponds to the addition ~' of 0.05% Cerium in the cast iron results in obtaining ins-. ~
tead of gre~ iron, a complete white hardening of the cast ~ ~ -: .
iron. It will be clear from the following examples of the .. : .
invention and particularly from example 5, that in the case of the al~mlnum cast iron to which this invention pertains, ~;
an increasing addition up to 1.5% misch metal, which corres-ponds to an addition of 0.56% Cerium in the cast iron, re-sults in reducing the hardening depth.
; Other details and features of the invention ` will stand out from the following non-limitative examples of ; grey aluminum cast iron which have been inoculated according - to the invention.
Each example comprisesa table of the iron characteristics according to the percentage of inoculating al-"' .~ ' ~4~37 ~i loy. By way of comparison, the characteristics have been given .~ ,i , ` for the same cast iron which has however been inoculated with : :
, ; 1% SiCa, the Ca content being 33%. By way of additional com-''~` parison, in column 5 has been yiven (Si iron HB), the normal .~ Brinell hardness (HB) of a grey silicon cast iron the tensile ,~ strength of which corresponds to the tensile strength of the ...~
cast iron according to the invention, as shown in column 3. The - Brinell hardness given in column 5 has been computed according to the usual formula:
HB~= 100 + 4.3~
being the tensile strength.
Composition of the cast iron ';: ':
C Si Mn P S Al :' 3.74 0.15 0.53 0.018 0.045 2.35 x .
sllicon as determined beore inoculating Inoculating with an alloy of the type FeSi(RE) comprised of:
. - RE : Misch metal : 22%
.,1 - Silicon : 40 ,j - Remainder : iron Table 1 , : % inoculat- Hardening Tensile HB 10/3000/15 Si ... ~ing medium depth, mm strength kgf/mm2 iron .. added kgf/mm (~ 30 mm) HB :~
,, (1? (2) ~ 30 mm) (4) (5) ... ~
.~ 0.3 1.5 30.2 177 230 .
.. 0.4 -0.5 31.6 178 236 ~ -. 0.5 0 30.5 178 236 ; 30 1% SiCa 1 30.5 __ 174 _ 231 ., - ~ 30 mm means that tests or measurements have been made on ` test pieces extracted from bars of a diameter of 30 mm in -rough cast condition;
- 5 - ; ~
~;', '' .
- HB lOJ3000/15 is the international symbol giving the hard-ness measured by the Brinell method, with a ball of 10 mm, ~ loaded with 3000 kgf for 15 seconds.
: EXAMPLE 2 .
, Composition of the cast iron - -- . . .
,; x ;, C Si Mn P S Al 2.92 0.21 0.55 0.020 0.050 2.58 XSilicon as determined before inoculating Inoculation with an alloy of the type FeSi(RE) comprised of:
- RE : Misch metal : 22%
- Silicon : 40%
- Remainder : iron Table 2 ,: :-. .:
. . .__ , ., % inocula- Hardening Tensile HB 10j3000/15 Si :~
ting medium depth, mm strength Kgf/mm2 iron added Kgf/mm2 (~ 30 mm) HB
(~ 30 mm) -~
(1) (2) (3) (4) (5) 0.3 7.5 42.1 -- 242 282 `
0.4 6.5 ~2.5 241 283 " 20 0.6 1.5 44.6 239 292 `, 0.8 0.5 47 235 302 l 1% SiCa _ _ 46.8 236 301 :~ EXAMPLE 3 :j '- '-- ~, Composition of the cast iron , C SiX Mrl P S Al 2.94 0.26 0~55 0.016 0.072 2.38 XSilicon as determined before inoculating Inoculating with an alloy of the type Si (RE) com-' prised of :
- RE: Misch metal : 66%
- Silicon : 33%
,.
-'~ TABLE 3 ;~` % inocula- Hardening tensllë ¦ HB 10/3000/15 Si ting me- dep~, mm strength kgf/mm2 iron dium added kgf/mm2 (~ 30 mm) HB
(~ 30 mm) (1) (2) (3) (4) (5) "." ~.. __ .~ ... . ..
0.3 10.5 47.5 265 304 0.4 6 49.2 268 311 0.6 0 , 52.1 268 325 1% SiCa 4 47.8 256 305 ~, :
C_mposition of the cast iron C Si Mn P S Al 3.13 0.15 0.57 0.025 0.044 2.08 XSilicon as determined before inoculating f-~ Inoculating wlth an alloy of the type FeSi(Tn) comprised of :
` . R~ ;
~ Mlsch metal : 5%
:' - Silicon : 40%
.,. . :
- Remainder : iron % inocula- Hardening Tensile HB 10/3000/15 Si ting me- depth, mm strength kgf/mm2 iron dium added kgf/mm2 (~ 30 mm) HB
; (~ 30 mm) ` (1) (2) (3) ~4) (5) ,. , _ ',' :.
0.3 10.5 35.1 247- 252 0.6 6.5 36.2 245 256 1 1.5 37.6 246 262 ' 1.5 0 42.3 242 282 1% SiCa 43.? 246 286 `' ,~ ~,:
` 30 ~ 7 ~
`~ ~ lr~4i~237 -' Composition of the cast iron C Si Mn P S ~1 - 3.37 0.130.60 0.028 0.054 2.65 XSilicon as determined before inoculating (R~) ~- Inoculating with an alloy of the type FeSi~
comprised of: ;
RE ~ -- Tn : Misch metal : 75%
' , - Silicon: 12.5%
- Remainder: iron ~ABLE 5 -.... ,.__......... . . ~ . ~., : , % inocula- Hardening Tensile HB 10/3000/15 Si - ~
ting me- depth, mm strength kgf/mm2 iron ;
dium kgf/mm2 (~ 30 ITun) HB
(~ 30 mm) -., ,' (1) ~. . .__ ' ~ ~5) ~. .
0.3 15 35.9 229 254 0.8 7 42.7 249 284 ^ -, 1.2 4 42.5 232 283 ,~
', 1.5 2 45.1 242 294 20 lYo SiCa 47 248 302 C SiX Mn P S Al , 3.32 0.130057 0.026 0.071 2025 .. ~' . . . :
Silicon as determined before inoculating Inoculating with an alloy of the type FeSi~Ca :: , , comprised of:
-~: Misch metal: 25%
- Calcium: lO~/o .' ' , ~ .
4Z;~3'~
- Silicon : 40~/0 - Remainder : iron ~, , ._ . . ...... , ._, .. , . , ., __ % inocula- Hardening Tensile HB 10/3000/15 Si ~ ting me- depth, mm strength kyd/mm2 iron -~ dium added kgf/mm2 (0 30 mm) HB
. (0 30 mm) (1) (2) (3~ (4) (5) . ___. ...._ ~ 0.3 14 34.9 245 250 :, :,. 0.6 10 34.8 235 250 : -1 3 38.1 246 264 :. 1.5 1 41.6 241 279 , 10 1% SiCa . __ 3904 236 270 . . EXAMPLE 7 ... . ... .
: Composition of the cast iron . C Si Mn P S Al 3.13 0.16 0.58 0.027 0.047 2.44 ` A XAluminum as determined before inoculating Inoculating with an alloy of the type FeAl~ t ~.
comprised of :
R~
Misch metal : 50/0 - Aluminum : 25%
- - Iron : 25%
, , ' ~;'' , ' ' .~
'.' ` , .. .. .
::' . ' ' ''~
' ~, , ,. ' ' ' ` ' ~' ' ' , , "' ' '~
_ ;~ :
~ 4Z~3 ~
. .
.
, ` ... . . ........................... . ,.
% inocula- :~ardening Tensile HB lO/3000/15 Si ting me- depth, mm strength kgf/mm2 iron dium added kgf/mm2 (~ 30 mm) HB
(~ 30 mm) , (l) (2) (3) (4) (5) . ~ .. _ . _ .... . _ ......
;~ 0.3 6 42.3 246 282 .
0.6 2 44.9 245 293 . l l 45.6 243 296 ~ 10 1% SiCa _ 43. 2 246 286 ;. ..
The examples show that it is desirable to . . .
use an inoculating alloy the active element of which comprises . ' :
between about 2~/o (22% in the examples) and about 70% (66% in the examples) by weight of the alloy.
; It is then possible to use but from O. 3 to .. .. . . .
~, O.~/O by weight of inoculating alloy to obtain very satisfying , characteristics in the cast iron, as regards the three con-ditions under consideration : low ledeburitic hardening, high tensile strength, not too high a hardness.
r', me tablesalso show (columns 3 and 5) that the aluminum cast ironsinoculated with an alloy based on rare ~ ;
earths are substantially less hard, for the same strength, :~ than the conventional silicon cast iron.
. , ~: ., .
It must be understood that the invention is in no way limited to the above examples and that many changes can be brought therein without departing from the scope of the invention as defined by the appended claims.
For instance other inoculating alloys such as Al ~ ; Cu (TR)--; CuSi-~R~ ; Ni ~ ; NiSit~R~ can be used. ~ :
.
." , . ; .
:,. . .
10seodymium.
It is significant to demonstrate the impor-tance o~ this invention, to mention as disclosed in an arti-, . , cle by Dawson in BCIRA Journal of Research 1961, vol. 9, ~ -p.l99, fig. 7, that an addition of more than 0.1 % misch me-tal to silicon cast iron, which corresponds to the addition ~' of 0.05% Cerium in the cast iron results in obtaining ins-. ~
tead of gre~ iron, a complete white hardening of the cast ~ ~ -: .
iron. It will be clear from the following examples of the .. : .
invention and particularly from example 5, that in the case of the al~mlnum cast iron to which this invention pertains, ~;
an increasing addition up to 1.5% misch metal, which corres-ponds to an addition of 0.56% Cerium in the cast iron, re-sults in reducing the hardening depth.
; Other details and features of the invention ` will stand out from the following non-limitative examples of ; grey aluminum cast iron which have been inoculated according - to the invention.
Each example comprisesa table of the iron characteristics according to the percentage of inoculating al-"' .~ ' ~4~37 ~i loy. By way of comparison, the characteristics have been given .~ ,i , ` for the same cast iron which has however been inoculated with : :
, ; 1% SiCa, the Ca content being 33%. By way of additional com-''~` parison, in column 5 has been yiven (Si iron HB), the normal .~ Brinell hardness (HB) of a grey silicon cast iron the tensile ,~ strength of which corresponds to the tensile strength of the ...~
cast iron according to the invention, as shown in column 3. The - Brinell hardness given in column 5 has been computed according to the usual formula:
HB~= 100 + 4.3~
being the tensile strength.
Composition of the cast iron ';: ':
C Si Mn P S Al :' 3.74 0.15 0.53 0.018 0.045 2.35 x .
sllicon as determined beore inoculating Inoculating with an alloy of the type FeSi(RE) comprised of:
. - RE : Misch metal : 22%
.,1 - Silicon : 40 ,j - Remainder : iron Table 1 , : % inoculat- Hardening Tensile HB 10/3000/15 Si ... ~ing medium depth, mm strength kgf/mm2 iron .. added kgf/mm (~ 30 mm) HB :~
,, (1? (2) ~ 30 mm) (4) (5) ... ~
.~ 0.3 1.5 30.2 177 230 .
.. 0.4 -0.5 31.6 178 236 ~ -. 0.5 0 30.5 178 236 ; 30 1% SiCa 1 30.5 __ 174 _ 231 ., - ~ 30 mm means that tests or measurements have been made on ` test pieces extracted from bars of a diameter of 30 mm in -rough cast condition;
- 5 - ; ~
~;', '' .
- HB lOJ3000/15 is the international symbol giving the hard-ness measured by the Brinell method, with a ball of 10 mm, ~ loaded with 3000 kgf for 15 seconds.
: EXAMPLE 2 .
, Composition of the cast iron - -- . . .
,; x ;, C Si Mn P S Al 2.92 0.21 0.55 0.020 0.050 2.58 XSilicon as determined before inoculating Inoculation with an alloy of the type FeSi(RE) comprised of:
- RE : Misch metal : 22%
- Silicon : 40%
- Remainder : iron Table 2 ,: :-. .:
. . .__ , ., % inocula- Hardening Tensile HB 10j3000/15 Si :~
ting medium depth, mm strength Kgf/mm2 iron added Kgf/mm2 (~ 30 mm) HB
(~ 30 mm) -~
(1) (2) (3) (4) (5) 0.3 7.5 42.1 -- 242 282 `
0.4 6.5 ~2.5 241 283 " 20 0.6 1.5 44.6 239 292 `, 0.8 0.5 47 235 302 l 1% SiCa _ _ 46.8 236 301 :~ EXAMPLE 3 :j '- '-- ~, Composition of the cast iron , C SiX Mrl P S Al 2.94 0.26 0~55 0.016 0.072 2.38 XSilicon as determined before inoculating Inoculating with an alloy of the type Si (RE) com-' prised of :
- RE: Misch metal : 66%
- Silicon : 33%
,.
-'~ TABLE 3 ;~` % inocula- Hardening tensllë ¦ HB 10/3000/15 Si ting me- dep~, mm strength kgf/mm2 iron dium added kgf/mm2 (~ 30 mm) HB
(~ 30 mm) (1) (2) (3) (4) (5) "." ~.. __ .~ ... . ..
0.3 10.5 47.5 265 304 0.4 6 49.2 268 311 0.6 0 , 52.1 268 325 1% SiCa 4 47.8 256 305 ~, :
C_mposition of the cast iron C Si Mn P S Al 3.13 0.15 0.57 0.025 0.044 2.08 XSilicon as determined before inoculating f-~ Inoculating wlth an alloy of the type FeSi(Tn) comprised of :
` . R~ ;
~ Mlsch metal : 5%
:' - Silicon : 40%
.,. . :
- Remainder : iron % inocula- Hardening Tensile HB 10/3000/15 Si ting me- depth, mm strength kgf/mm2 iron dium added kgf/mm2 (~ 30 mm) HB
; (~ 30 mm) ` (1) (2) (3) ~4) (5) ,. , _ ',' :.
0.3 10.5 35.1 247- 252 0.6 6.5 36.2 245 256 1 1.5 37.6 246 262 ' 1.5 0 42.3 242 282 1% SiCa 43.? 246 286 `' ,~ ~,:
` 30 ~ 7 ~
`~ ~ lr~4i~237 -' Composition of the cast iron C Si Mn P S ~1 - 3.37 0.130.60 0.028 0.054 2.65 XSilicon as determined before inoculating (R~) ~- Inoculating with an alloy of the type FeSi~
comprised of: ;
RE ~ -- Tn : Misch metal : 75%
' , - Silicon: 12.5%
- Remainder: iron ~ABLE 5 -.... ,.__......... . . ~ . ~., : , % inocula- Hardening Tensile HB 10/3000/15 Si - ~
ting me- depth, mm strength kgf/mm2 iron ;
dium kgf/mm2 (~ 30 ITun) HB
(~ 30 mm) -., ,' (1) ~. . .__ ' ~ ~5) ~. .
0.3 15 35.9 229 254 0.8 7 42.7 249 284 ^ -, 1.2 4 42.5 232 283 ,~
', 1.5 2 45.1 242 294 20 lYo SiCa 47 248 302 C SiX Mn P S Al , 3.32 0.130057 0.026 0.071 2025 .. ~' . . . :
Silicon as determined before inoculating Inoculating with an alloy of the type FeSi~Ca :: , , comprised of:
-~: Misch metal: 25%
- Calcium: lO~/o .' ' , ~ .
4Z;~3'~
- Silicon : 40~/0 - Remainder : iron ~, , ._ . . ...... , ._, .. , . , ., __ % inocula- Hardening Tensile HB 10/3000/15 Si ~ ting me- depth, mm strength kyd/mm2 iron -~ dium added kgf/mm2 (0 30 mm) HB
. (0 30 mm) (1) (2) (3~ (4) (5) . ___. ...._ ~ 0.3 14 34.9 245 250 :, :,. 0.6 10 34.8 235 250 : -1 3 38.1 246 264 :. 1.5 1 41.6 241 279 , 10 1% SiCa . __ 3904 236 270 . . EXAMPLE 7 ... . ... .
: Composition of the cast iron . C Si Mn P S Al 3.13 0.16 0.58 0.027 0.047 2.44 ` A XAluminum as determined before inoculating Inoculating with an alloy of the type FeAl~ t ~.
comprised of :
R~
Misch metal : 50/0 - Aluminum : 25%
- - Iron : 25%
, , ' ~;'' , ' ' .~
'.' ` , .. .. .
::' . ' ' ''~
' ~, , ,. ' ' ' ` ' ~' ' ' , , "' ' '~
_ ;~ :
~ 4Z~3 ~
. .
.
, ` ... . . ........................... . ,.
% inocula- :~ardening Tensile HB lO/3000/15 Si ting me- depth, mm strength kgf/mm2 iron dium added kgf/mm2 (~ 30 mm) HB
(~ 30 mm) , (l) (2) (3) (4) (5) . ~ .. _ . _ .... . _ ......
;~ 0.3 6 42.3 246 282 .
0.6 2 44.9 245 293 . l l 45.6 243 296 ~ 10 1% SiCa _ 43. 2 246 286 ;. ..
The examples show that it is desirable to . . .
use an inoculating alloy the active element of which comprises . ' :
between about 2~/o (22% in the examples) and about 70% (66% in the examples) by weight of the alloy.
; It is then possible to use but from O. 3 to .. .. . . .
~, O.~/O by weight of inoculating alloy to obtain very satisfying , characteristics in the cast iron, as regards the three con-ditions under consideration : low ledeburitic hardening, high tensile strength, not too high a hardness.
r', me tablesalso show (columns 3 and 5) that the aluminum cast ironsinoculated with an alloy based on rare ~ ;
earths are substantially less hard, for the same strength, :~ than the conventional silicon cast iron.
. , ~: ., .
It must be understood that the invention is in no way limited to the above examples and that many changes can be brought therein without departing from the scope of the invention as defined by the appended claims.
For instance other inoculating alloys such as Al ~ ; Cu (TR)--; CuSi-~R~ ; Ni ~ ; NiSit~R~ can be used. ~ :
.
." , . ; .
:,. . .
Claims (9)
1. Grey cast iron, with lamellar graphite, high mechanical strength and low ledeburitic hardness, comprising, in weight percent, 2 to 4% C
0 to 1% Si 1 to 3% Al 0 to 0.7% Mn 0 to 0.05% S
0 to 0.1% P
with the balance essentially iron, and inoculated with 0.3 to 2% of an inoculating alloy, in which the inoculating alloy contains from 5 to 75% rare earths.
0 to 1% Si 1 to 3% Al 0 to 0.7% Mn 0 to 0.05% S
0 to 0.1% P
with the balance essentially iron, and inoculated with 0.3 to 2% of an inoculating alloy, in which the inoculating alloy contains from 5 to 75% rare earths.
2. Grey cast iron as claimed in claim 1, in which the active inoculating element is misch metal.
3. Grey cast iron as claimed in claim 1, in which said cast iron is inoculated with from 0.5 to 2% inoculating alloy.
4. Grey cast iron as claimed in claim 1, in which the inoculating alloy contains from 20 to 70% rare earths.
5. Grey cast iron as claimed in claim 2, in which the inoculating alloy contains from 22% to 66% rare earths.
6. Grey cast iron as claimed in claim 2, in which said cast iron is inoculated with 0.3 to 0.8% inoculating alloy.
7. Grey cast iron as claimed in claim 6, in which the inoculating alloy has a maximum content of 40% Si.
8. Grey cast iron as claimed in claim 1, in which the inoculating medium is chosen from the group comprising Si(RE) ; FeSi(RE) FeAlSi(RE) ; FeAl(RE) Al(RE) ; FeAl(RE) CuSi(RE) ; Ni(RE) ; NiSi(RE)
9. Grey cast iron as claimed in claim 1, in which the inoculating alloy contains an additional active element chosen from the group comprised of Ca, Ba, Sr.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE142346A BE812706R (en) | 1974-03-22 | 1974-03-22 | Lamellar graphitic grey cast iron - having high strength and low ledeburite formation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1042237A true CA1042237A (en) | 1978-11-14 |
Family
ID=3842646
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA223,182A Expired CA1042237A (en) | 1974-03-22 | 1975-03-21 | Grey cast iron |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS514016A (en) |
| CA (1) | CA1042237A (en) |
| CH (1) | CH602948A5 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5356834A (en) * | 1976-11-01 | 1978-05-23 | Hazama Gumi | Construction method of underground structure that use tunnel |
| JPS5365215A (en) * | 1976-11-25 | 1978-06-10 | Kubota Ltd | Cast iron with high damping capacity |
| JPS5487628A (en) * | 1977-12-21 | 1979-07-12 | Chiyurusukii Pk Tefunorogichie | Chillproof cast iron |
| JPS55128304A (en) * | 1979-03-28 | 1980-10-04 | Hitachi Ltd | Rolling mill with surface flaw detector of roll |
| JPH0347324A (en) * | 1989-07-13 | 1991-02-28 | Kubota Corp | Plural layer column construction for underground structure |
| JP2520034B2 (en) * | 1990-01-17 | 1996-07-31 | 大豊建設株式会社 | segment |
| JP5466247B2 (en) * | 2009-02-12 | 2014-04-09 | テクシド ド ブラジル リミターダ | Method for obtaining highly resistant gray cast iron alloys for combustion engines and general castings |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5636214B2 (en) * | 1973-08-25 | 1981-08-22 |
-
1975
- 1975-03-18 CH CH341275A patent/CH602948A5/en not_active IP Right Cessation
- 1975-03-21 CA CA223,182A patent/CA1042237A/en not_active Expired
- 1975-03-22 JP JP3486575A patent/JPS514016A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| CH602948A5 (en) | 1978-08-15 |
| JPS514016A (en) | 1976-01-13 |
| JPS559052B2 (en) | 1980-03-07 |
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