CA1064739A - Valve seat material for an internal combustion engine - Google Patents
Valve seat material for an internal combustion engineInfo
- Publication number
- CA1064739A CA1064739A CA221,563A CA221563A CA1064739A CA 1064739 A CA1064739 A CA 1064739A CA 221563 A CA221563 A CA 221563A CA 1064739 A CA1064739 A CA 1064739A
- Authority
- CA
- Canada
- Prior art keywords
- valve seat
- internal combustion
- combustion engine
- lead
- seat material
- 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
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/02—Making ferrous alloys by powder metallurgy
- C22C33/0207—Using a mixture of prealloyed powders or a master alloy
- C22C33/0228—Using a mixture of prealloyed powders or a master alloy comprising other non-metallic compounds or more than 5% of graphite
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/02—Making ferrous alloys by powder metallurgy
- C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
- F01L3/02—Selecting particular materials for valve-members or valve-seats; Valve-members or valve-seats composed of two or more materials
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Powder Metallurgy (AREA)
Abstract
TITLE OF THE INVENTION
A valve seat material for an internal combustion engine ABSTRACT OF THE DISCLOSURE
The present invention relates to a valve seat materi-al for an internal combustion engine, which comprises a sinter-ed ferrous alloy having the composition by weight: 3-15 % moly-bdenum, 2-12 % cobalt, 0.1-200 % carbon, optionally 0-15 % lead and 0-8 % glass and the remainder being iron except fox usual impurities and trace elements. In cases There it is desirable to raise the self-lubricating property further, in particular, 0.5-10 % tungsten or 0.5-10 % tungsten and 0.5-8 % nickel can, in addition, be incorporated is the matrix.
A valve seat material for an internal combustion engine ABSTRACT OF THE DISCLOSURE
The present invention relates to a valve seat materi-al for an internal combustion engine, which comprises a sinter-ed ferrous alloy having the composition by weight: 3-15 % moly-bdenum, 2-12 % cobalt, 0.1-200 % carbon, optionally 0-15 % lead and 0-8 % glass and the remainder being iron except fox usual impurities and trace elements. In cases There it is desirable to raise the self-lubricating property further, in particular, 0.5-10 % tungsten or 0.5-10 % tungsten and 0.5-8 % nickel can, in addition, be incorporated is the matrix.
Description
BACKGROU~ OF T~E INVEN~ION
;~ ~his invention relates to a valve seat material for an internal combustion engine. Of late, the characteristics required ~or valve seat materials tend to become increasingly severe with the size reduction o~ an internal combustion en-gine, with the rising of the output thereof and wi~h the in-crease o~ kinds of fuels used~ Generally a valve seat materi-al ~or an internal combustion engine should have the followins characteristics: -1) Sufficient strength for an impact load at a hightemperature such as b~ beating o~ a valve 7
;~ ~his invention relates to a valve seat material for an internal combustion engine. Of late, the characteristics required ~or valve seat materials tend to become increasingly severe with the size reduction o~ an internal combustion en-gine, with the rising of the output thereof and wi~h the in-crease o~ kinds of fuels used~ Generally a valve seat materi-al ~or an internal combustion engine should have the followins characteristics: -1) Sufficient strength for an impact load at a hightemperature such as b~ beating o~ a valve 7
2) ~xcellent wear resistance at a high temperature, in particular, in the case of the exhaust side exposed to an exhaust g?S at a high temperature,
3) Excellent heat resistln~ strength and
4) Cheapness.
Up to the present time, ordinary c,ast irons, low alloy cast . irons 3 ch~omium alloys and stainless cast steels have been ~ 9 1 used as a valve seat material for an internal combustion en-gine, but these materials have problems on the ability in an internal oombustion engine using a lead-free gasoline or liquid propane gas~ ~he valve seat on the exhaust side is always ex-posed ~o a combustion gas at a high temperature during the ope-ration of an internal combustion engine and subjected to an impact load by the beating of a valve and to a sliding action due to an irregular rotation of valve~ In an internal combus-tion engine using the ordinary lead-containing gasoline~ the .
lead contained in gasoline is converted into lead oxide and lead sulfate and sulfur~ phosphorus, calcium and sodium con-tained in lubricating oil or gasoline are converted into other combustion products such as calcium oxide, sodium oxide, phosphorus oxide and calcium sulfate, which may possibly form a lubricating film pla~ing a role as an antioxidant or anti-friction material between the contact surfaces of the valve and valve seat. In another internal combustion engine using a lead-~ree gasoline~ on the contra:r~, such lubricating pro-; ducts are not sufficientl~ formed and the valve and valve seat are brought into direct contact at a high temperature, resulting in rapid wearing of the valve seat and, sometimes, the valve itself due to adhesive wearing. Consequentl~, the englne cannot be opera~ed normally, since there is no tappet ; clearance due to such abnormal wearing~
.
SUMM~RY OF ~HE IN~ENTIOM
It is an object of the invention to provide an improv-ed valve seat material for an internal combustion engine, which overcomes the above described difficulties and which is resist-ant -to oxidation and wearing at high temperatures.
It is another object of the invention to provide a valve seat material for an internal combustion engine~ which is suitable for u.se of lead-free gasolines.
~ 73~
1 I-t is a further object of the invention to pro~ide a valve seat material for an internal combustion engine, which is capable of satisfying the severe requirements for internal combustion engines and which can be produced by the mass pro-duction system.
~hese objects can be accomplished by a valve seat for an internal combustion engine, which comprises a sintered ferrous alloy having the composition: 3-15 ~ by weight moly-bdenum, ~-12 % cobalt, 0~1-2.0 % carbon, 0-15 % lead, prefer-ably 2-15 ~ lead, and 0-8 ~ glass, preferably 0.5-8 ~ glass and the remainder being iron ex¢ept for usual impurities and trace elements.
DE~AI~ED DESCRIP~IO~ OF ~HE INVEN~ION
he above mentioned alloy has particular application to a valve seat insert for a reciprocating internal combustïon l~ ~ engine and can be produced preferably by mixing the correspond-I ing powders in the required proporl;ions, pressing the mixture to form a compact and sintering the compact.
~he features of the alloy according to the invention are as follows:
1 1) ~he base matrix is a sintered ferrous alloy con-taining Co 9 Mo and C as alloy elements.
` ~ 2) A phase of Mo-containing hard compounds such as FeMo, ~e3Mo2, FeMo3 and (FeMo)6C is dispersed in the base matri~.
3) At least one of lead and a low melting glass are optionally incorporated in this alloy, which are capable of meltin~ and forming a lubricating film on the surface of a ; valve seat during the operation o~ an internal combustion en-gine.
3o ~he alloy of the invention has generally the composi-tion by weight: 3-15 % molybdenum~ 2-12 % cobalt, 0.1-2 ~ carbon and the remainder being ixon except ~or usual impurities and ~a~3s~
1 trace elementsO In a case where it is desirable to raise the self-lubrica-ting propert~ further, in particular7 at least one of 2-15 % lead and 0.5-8 % glass can, in addition, be inco~po-rated therein.
In the above mentioned composition of the valve seat material according to the invention~ molybdenum dissolves in iron with other alloy elements to form solid solutions which strengthen the matrix and raise the heat resistance, and to ..
form a phase of hard compounds containing iron and carbon and having a hardness mHv (Micro Vickers Hardness) of 800 to 1500~ which assures of the wear resistance. ~he range of quantity of the molybdenum to be added is limited to 3 to 15 ~7 since if less than ~ %, the quantity of the foxmed hard phase is too little to raise the wear resistance and if more than 15 %, the machinability is lowered and the ~uality become~
; brittle~
Cobalt enters partly the molybdenum hard phase also, but the most part of cobalt dissolves in tke iron matrix to ~orm solid solutions, thus contributing to the improvement of the heat resistance of the matrix. ~he range of quantity of the cobalt to be added is limited to 2 to 12 ~ since if less than 2 %, the effect of increasing the heat resistance of the matrix i~ little and even if more than 12 %, this effect is ~ot so increased~
Carbon combines with molybdenum and iro~ to form their carbide~, thus improving the strength of the matri~
~he carbon is added in a ~uantity range of 0~1 to 2 ~, since if less than 0.1 %, this effect is little and if more than 2 %, the quality becomes brittle.
~ead plays a role of forming a lubricating film on the ~urface of a valve seat and preventing the valve and valve ~eat from the adhesion of metal during the running of the en-gine~ A preferred range of quantity of the lead to be added ~ 73~
1 is from 2 to 15 ~, since if less than 2 ~, this effect is lit-tle and if moxe than 15 ~, the strength of the alloy is lowered~
~ ow melting point glass plays also a xole of forming a lubricating film on the surface o~ a valve seat and prevent-ing the valve and valve seat from the adhesion of metal, and, in paxticular, forms a strong film at a high temperature of at ¦ least 400 C to thus raise -the wear resistance. As such a low melting point glass there can be used those containing B203, ~ P205, ZnO and PbO as main components and melting at a temper-ature of lower than 500 a, for example, 30 % B203 - 30 % P205 - 30 % PbO and 50 ~ PbO - 30 % ZnO - 20 ~ B203. A preferred - range of quantity of the low melting glass is 0.5 to 8 %, since if less than 0.5 %, the lubricating effect is little and if more than 8 ~, the strength of the alloy is lowered.
In one preferred embodiment of the valve seat mate-rial according to the present invention~ tungqten is further incorporated in the above described alloy composition in a j proportion of 0.5 to 10 %. In this case, the sintered ferrous allo~ has generally the composition by weight: 3-15 % molybde-num, 2--12 % cobalt, 0.5-10 % W, 0.1-2 ~ carbon and the remain-der ~eing iron except ~or usual impurities and trace elements.
In cases where it is desirable to raise the self-lubricating , property, in particular, at least one of 2-15 % lead and 0.5-8 % glass can, in addition, be incorporated in the matrix.
~ungsten having the similar effect to molybdenum dissolves in iron to form solid solutions, thus stren~thening the matrix and raising the heat resistance. ~he range of quantity of the tungsten to be added is limited to 0.5 to 10 %, since if less than 0~5 ~, this effect is little and if more than 10 ~ the machinability is markedly deterioxated~
In another preferred embodiment of the valve seat material according to the inventio~, tungsten in a proportion of 0.5 to 10 ~ and nickel in a proportion of 0~5 to 8 % are 6~73~
1 further incorporated in the above described allo~ composition.
~hat is to sa~, the sintered ~errous alloy has generall~ the composition b~ weight: 3~15 ~ mol~bdenum, 2-12 % cobalt, 0.5-10 ~ tungsten, 0.5-8 % nickel~ 0.1 2 % carbon and the remain-der being iron except for usual impurities and trace elements.
In cases where it is desirable to raise further the self-lubri-cating property~ in particular9 at least one oP 2-15 % lead and 0.5-8 ~o glass ~-an, in addition, be incorporated in the matrix.
. . .
Nickel serves to stxengthen the ferrite and to raise the tough-ness of the matrix~ ~he range of quantity of the nickel to be added is limited to 0~5 to 8 ~, since if less than 0.5 %, this e~ect is little, while if more than 8 ~, precipitation of cax-bides is suppressed too much.
~ he present invention will be further illustrated in greater detail in the following examples and comparative exam-ples. It will be self-evident to those skilled in the art that the ratios? ingredients in the following formulations and the order of operations can be modified within the scope o~ the present invention. ~herefoxe~ the prese~t invention is not ~20 to be interp~eted as being limited to the following examples.
All percents are by weight unless otherwise indicated.
.
A reduced iron powder of -100 mesh (~yler standard sieve), ~erromolybde~um (50 % Mo, 0.06 % C, 1.26 % Si) powder o~ -200 me~h, cobalt powder of -325 mesh, lead powder of -?50 me~h and low melting point glass powder o~ 30~oB203-30~P2S~ bO
were mixed so as to give each o~ the following compositions, formea in a densit~ of 90 % and sintered at 1130 C for 30 min- -utes ln a reducing atmosphere:
473~
1 Sample ~ Chemical Composition Density ~ardness No. (by wei~ht- ~e remainder) (y) fHRB*~
. _ , 1 Fe-3%Mo-0.1%C (for comparison) 90 60 2 ~e-5,~Mo-1%C (for comparison) 90 61 ~e-1o%Mo-1%a (for comparison) 90 . 65 4 Fe-15~Mo-1%C (for comparison) 90 68 Fe-15~Mo-2ya (for comparison 90 73 6 ~e-10%Mo-1%C-4%Pb-2%G**
(for comparison) 90 64 7 Fe-3%Mo-2%Co-0.1~C 90 G2 ~e-5%Mo-8~Co-1%C 90 73 ; 9 . ~e-10YMo-8%Co-1yC 90 74 ~e-15%Mo-8%Co-1%C 90 78 e-10yMo-4~Co-1%C 90 74 12 ~e-105~Mo~11%Co-1%C 90 79 Fe-15%Mo-12%Co-2~oC 9 78 14 Fe-10~Mo-8YCo-1%C-4YPb 90 72 Fe-10~Mo-8%Co-1%C-2%G 9 72 16 Fe-10%Mo-8~Co-1YC-4~Pb-2%G 90 73 Note: * Rockwell Hardnes~ B Scale ** Glass : EXAMPIE 2 :
A reduced iron powder of -100 mesh, ferromolybdenum (50 % Mo, 0.06 ~o C, 1~26 % Si~ powder o~ -200 mesh, tungsten , powder sf 325 mesh~ cobalt powder of -325 mesh, lead powder of -250 mesh and low melting point glass powder of 30YOB2O~-30%P205-30~oPbO were mixed so as to gi~e each of the following compositions, formed in a density of 90 % and sintered at 1130 : a for 30 minutes in-a reducing atmosphere:
73~ ~
Sample Chemical Composition DensityHardness No~ ~ (%) ~HRB) A 17 Fe-3%Mo-2~-2%W-0~190C 90 71 . 18 Fe-5%Mo-8%Co-8,6W-1%C 9 76 19 Fe-'10%Mo-5%Co 0.5%W-1.5;qÇa 9 85 Fe-1 0~6Mo-8,6Co~3%W-1~C 90 77 21 Fe-15%Mo-8%Co-3%W~ 1%C 90 81 22 Fe-10~Mo-4%Co-5yW-1,6C 90 77 23 Fe-10~Mo-11%Go-550~W-1%C 90 82 24 Fe-15,~Mo-12%Co-1090W-2%C 90 83 ~t 25 Fe-10%Mo-8%Co-5%W-1%C-4,6Pb 90 75 26 Fe-10,bMo-8%Co 5%W-1%C-2%G 90 75 27 Fe-10%Mo~8~6Co-5%W~1~6C-4%Pb-2%G 9 76 :EXAMPIE 3 A reduced iron powder of -100 mesh, ~erromolybdenum (50 % Mo, 0 06 % C, 1.26 % Si) powder of -200 rnesh, tungsterl powder of -325 mesh? cobalt powder of -325 mesh, nickel car-~; ~ bonyl powder of -325 mesh, lead powder of -250 mesh and low melting point glass powder of 30%B203-30~oP205-3090PbO were 20 mixed so as to give each o~ the ~ollowing compositions, îormed in a density of 90 % and then sintered at 1130 C for 30 min-ute~3 in a reducing atmosphere:
: Sample Chemical Composition Densi-ty3~ardne.ss : No. (by weight. :Ee remainder) _ _ (%)_(BRB~
28 Fe-3,6Mo-2~Co--2%W-296Ni-0.l%a 90 73 - ~ ~ 29 Fe-5%Mo-89o'Co-8%W-3%Ni-1%C 90 79 Fe~ 6Mo-5%ao-3,~W-0.5/Ni-1%C 90 . 86 31 Fe~ oMo-8%ao~3%W-3%Ni-1%a 90 80 32 Fe-10%Mo-4%Co-5%W-6~6Ni~ a 90 78 33 Fe-15%Mo-12%Co-10%W-8/6Ni-2%a 90 84 34 Fe-10~oMo-8%Co-5%W-3%Ni-1%a-4%Pb 9 78 Fe~ Mo-8%Co-5%W-3~oNi- 1%C-2%G 90 79 36 Fe-10%Mo-8%Co-5%W-3%Ni-1~C-4%Pb-2%G 90 79 .
4~73se 1 ~he so obtained Samples 1 to 36 (~xampies 1-3) were worked or fini~hed in a predetermined size and then subjected to the ~ollowing durability test:
Test of Durabilit~
Using a 360 cc~ water-cooling, two c~linder- a~d two caburetterengine at 7500 rpm with ~ull throttle and full load~
the tappet gap was first adjusted to 0.1 m/m and a period of time was measured irre~pective of the right and left c~linders when the gap became zero. ~he life of a ring for the valve seat was de~ined by the measured period of time. A gasoline was used having an octane number of 87 and containing lead in a quar.tit~ of 0.002 g/gallon.
~he measured results are tabulated below:
~able 1 Durability_(hrs) Sample No~irst ~estSecond ~est ` 3 51 60 ~ 5 65 64 :
; - 11 89 82 16 186 , 178 _ 9 _ -~ii9L73~
. 148 151 26 1~7 131 .
29 96 g5 '. ~ . 30 96 . g8 31 ~5 101 :: . 33 126 132 .34 156 162 I~ ~ 36 206 211 :~; 2~ As is evident from these results, the sintered ferrous alloys ~ having bhe composition according to the present i~vention can : : :: ~
fa~ouxabl~ be compared i~ darability with the ~imilar Fe Mo alloys we had~proposed. I
.
Up to the present time, ordinary c,ast irons, low alloy cast . irons 3 ch~omium alloys and stainless cast steels have been ~ 9 1 used as a valve seat material for an internal combustion en-gine, but these materials have problems on the ability in an internal oombustion engine using a lead-free gasoline or liquid propane gas~ ~he valve seat on the exhaust side is always ex-posed ~o a combustion gas at a high temperature during the ope-ration of an internal combustion engine and subjected to an impact load by the beating of a valve and to a sliding action due to an irregular rotation of valve~ In an internal combus-tion engine using the ordinary lead-containing gasoline~ the .
lead contained in gasoline is converted into lead oxide and lead sulfate and sulfur~ phosphorus, calcium and sodium con-tained in lubricating oil or gasoline are converted into other combustion products such as calcium oxide, sodium oxide, phosphorus oxide and calcium sulfate, which may possibly form a lubricating film pla~ing a role as an antioxidant or anti-friction material between the contact surfaces of the valve and valve seat. In another internal combustion engine using a lead-~ree gasoline~ on the contra:r~, such lubricating pro-; ducts are not sufficientl~ formed and the valve and valve seat are brought into direct contact at a high temperature, resulting in rapid wearing of the valve seat and, sometimes, the valve itself due to adhesive wearing. Consequentl~, the englne cannot be opera~ed normally, since there is no tappet ; clearance due to such abnormal wearing~
.
SUMM~RY OF ~HE IN~ENTIOM
It is an object of the invention to provide an improv-ed valve seat material for an internal combustion engine, which overcomes the above described difficulties and which is resist-ant -to oxidation and wearing at high temperatures.
It is another object of the invention to provide a valve seat material for an internal combustion engine~ which is suitable for u.se of lead-free gasolines.
~ 73~
1 I-t is a further object of the invention to pro~ide a valve seat material for an internal combustion engine, which is capable of satisfying the severe requirements for internal combustion engines and which can be produced by the mass pro-duction system.
~hese objects can be accomplished by a valve seat for an internal combustion engine, which comprises a sintered ferrous alloy having the composition: 3-15 ~ by weight moly-bdenum, ~-12 % cobalt, 0~1-2.0 % carbon, 0-15 % lead, prefer-ably 2-15 ~ lead, and 0-8 ~ glass, preferably 0.5-8 ~ glass and the remainder being iron ex¢ept for usual impurities and trace elements.
DE~AI~ED DESCRIP~IO~ OF ~HE INVEN~ION
he above mentioned alloy has particular application to a valve seat insert for a reciprocating internal combustïon l~ ~ engine and can be produced preferably by mixing the correspond-I ing powders in the required proporl;ions, pressing the mixture to form a compact and sintering the compact.
~he features of the alloy according to the invention are as follows:
1 1) ~he base matrix is a sintered ferrous alloy con-taining Co 9 Mo and C as alloy elements.
` ~ 2) A phase of Mo-containing hard compounds such as FeMo, ~e3Mo2, FeMo3 and (FeMo)6C is dispersed in the base matri~.
3) At least one of lead and a low melting glass are optionally incorporated in this alloy, which are capable of meltin~ and forming a lubricating film on the surface of a ; valve seat during the operation o~ an internal combustion en-gine.
3o ~he alloy of the invention has generally the composi-tion by weight: 3-15 % molybdenum~ 2-12 % cobalt, 0.1-2 ~ carbon and the remainder being ixon except ~or usual impurities and ~a~3s~
1 trace elementsO In a case where it is desirable to raise the self-lubrica-ting propert~ further, in particular7 at least one of 2-15 % lead and 0.5-8 % glass can, in addition, be inco~po-rated therein.
In the above mentioned composition of the valve seat material according to the invention~ molybdenum dissolves in iron with other alloy elements to form solid solutions which strengthen the matrix and raise the heat resistance, and to ..
form a phase of hard compounds containing iron and carbon and having a hardness mHv (Micro Vickers Hardness) of 800 to 1500~ which assures of the wear resistance. ~he range of quantity of the molybdenum to be added is limited to 3 to 15 ~7 since if less than ~ %, the quantity of the foxmed hard phase is too little to raise the wear resistance and if more than 15 %, the machinability is lowered and the ~uality become~
; brittle~
Cobalt enters partly the molybdenum hard phase also, but the most part of cobalt dissolves in tke iron matrix to ~orm solid solutions, thus contributing to the improvement of the heat resistance of the matrix. ~he range of quantity of the cobalt to be added is limited to 2 to 12 ~ since if less than 2 %, the effect of increasing the heat resistance of the matrix i~ little and even if more than 12 %, this effect is ~ot so increased~
Carbon combines with molybdenum and iro~ to form their carbide~, thus improving the strength of the matri~
~he carbon is added in a ~uantity range of 0~1 to 2 ~, since if less than 0.1 %, this effect is little and if more than 2 %, the quality becomes brittle.
~ead plays a role of forming a lubricating film on the ~urface of a valve seat and preventing the valve and valve ~eat from the adhesion of metal during the running of the en-gine~ A preferred range of quantity of the lead to be added ~ 73~
1 is from 2 to 15 ~, since if less than 2 ~, this effect is lit-tle and if moxe than 15 ~, the strength of the alloy is lowered~
~ ow melting point glass plays also a xole of forming a lubricating film on the surface o~ a valve seat and prevent-ing the valve and valve seat from the adhesion of metal, and, in paxticular, forms a strong film at a high temperature of at ¦ least 400 C to thus raise -the wear resistance. As such a low melting point glass there can be used those containing B203, ~ P205, ZnO and PbO as main components and melting at a temper-ature of lower than 500 a, for example, 30 % B203 - 30 % P205 - 30 % PbO and 50 ~ PbO - 30 % ZnO - 20 ~ B203. A preferred - range of quantity of the low melting glass is 0.5 to 8 %, since if less than 0.5 %, the lubricating effect is little and if more than 8 ~, the strength of the alloy is lowered.
In one preferred embodiment of the valve seat mate-rial according to the present invention~ tungqten is further incorporated in the above described alloy composition in a j proportion of 0.5 to 10 %. In this case, the sintered ferrous allo~ has generally the composition by weight: 3-15 % molybde-num, 2--12 % cobalt, 0.5-10 % W, 0.1-2 ~ carbon and the remain-der ~eing iron except ~or usual impurities and trace elements.
In cases where it is desirable to raise the self-lubricating , property, in particular, at least one of 2-15 % lead and 0.5-8 % glass can, in addition, be incorporated in the matrix.
~ungsten having the similar effect to molybdenum dissolves in iron to form solid solutions, thus stren~thening the matrix and raising the heat resistance. ~he range of quantity of the tungsten to be added is limited to 0.5 to 10 %, since if less than 0~5 ~, this effect is little and if more than 10 ~ the machinability is markedly deterioxated~
In another preferred embodiment of the valve seat material according to the inventio~, tungsten in a proportion of 0.5 to 10 ~ and nickel in a proportion of 0~5 to 8 % are 6~73~
1 further incorporated in the above described allo~ composition.
~hat is to sa~, the sintered ~errous alloy has generall~ the composition b~ weight: 3~15 ~ mol~bdenum, 2-12 % cobalt, 0.5-10 ~ tungsten, 0.5-8 % nickel~ 0.1 2 % carbon and the remain-der being iron except for usual impurities and trace elements.
In cases where it is desirable to raise further the self-lubri-cating property~ in particular9 at least one oP 2-15 % lead and 0.5-8 ~o glass ~-an, in addition, be incorporated in the matrix.
. . .
Nickel serves to stxengthen the ferrite and to raise the tough-ness of the matrix~ ~he range of quantity of the nickel to be added is limited to 0~5 to 8 ~, since if less than 0.5 %, this e~ect is little, while if more than 8 ~, precipitation of cax-bides is suppressed too much.
~ he present invention will be further illustrated in greater detail in the following examples and comparative exam-ples. It will be self-evident to those skilled in the art that the ratios? ingredients in the following formulations and the order of operations can be modified within the scope o~ the present invention. ~herefoxe~ the prese~t invention is not ~20 to be interp~eted as being limited to the following examples.
All percents are by weight unless otherwise indicated.
.
A reduced iron powder of -100 mesh (~yler standard sieve), ~erromolybde~um (50 % Mo, 0.06 % C, 1.26 % Si) powder o~ -200 me~h, cobalt powder of -325 mesh, lead powder of -?50 me~h and low melting point glass powder o~ 30~oB203-30~P2S~ bO
were mixed so as to give each o~ the following compositions, formea in a densit~ of 90 % and sintered at 1130 C for 30 min- -utes ln a reducing atmosphere:
473~
1 Sample ~ Chemical Composition Density ~ardness No. (by wei~ht- ~e remainder) (y) fHRB*~
. _ , 1 Fe-3%Mo-0.1%C (for comparison) 90 60 2 ~e-5,~Mo-1%C (for comparison) 90 61 ~e-1o%Mo-1%a (for comparison) 90 . 65 4 Fe-15~Mo-1%C (for comparison) 90 68 Fe-15~Mo-2ya (for comparison 90 73 6 ~e-10%Mo-1%C-4%Pb-2%G**
(for comparison) 90 64 7 Fe-3%Mo-2%Co-0.1~C 90 G2 ~e-5%Mo-8~Co-1%C 90 73 ; 9 . ~e-10YMo-8%Co-1yC 90 74 ~e-15%Mo-8%Co-1%C 90 78 e-10yMo-4~Co-1%C 90 74 12 ~e-105~Mo~11%Co-1%C 90 79 Fe-15%Mo-12%Co-2~oC 9 78 14 Fe-10~Mo-8YCo-1%C-4YPb 90 72 Fe-10~Mo-8%Co-1%C-2%G 9 72 16 Fe-10%Mo-8~Co-1YC-4~Pb-2%G 90 73 Note: * Rockwell Hardnes~ B Scale ** Glass : EXAMPIE 2 :
A reduced iron powder of -100 mesh, ferromolybdenum (50 % Mo, 0.06 ~o C, 1~26 % Si~ powder o~ -200 mesh, tungsten , powder sf 325 mesh~ cobalt powder of -325 mesh, lead powder of -250 mesh and low melting point glass powder of 30YOB2O~-30%P205-30~oPbO were mixed so as to gi~e each of the following compositions, formed in a density of 90 % and sintered at 1130 : a for 30 minutes in-a reducing atmosphere:
73~ ~
Sample Chemical Composition DensityHardness No~ ~ (%) ~HRB) A 17 Fe-3%Mo-2~-2%W-0~190C 90 71 . 18 Fe-5%Mo-8%Co-8,6W-1%C 9 76 19 Fe-'10%Mo-5%Co 0.5%W-1.5;qÇa 9 85 Fe-1 0~6Mo-8,6Co~3%W-1~C 90 77 21 Fe-15%Mo-8%Co-3%W~ 1%C 90 81 22 Fe-10~Mo-4%Co-5yW-1,6C 90 77 23 Fe-10~Mo-11%Go-550~W-1%C 90 82 24 Fe-15,~Mo-12%Co-1090W-2%C 90 83 ~t 25 Fe-10%Mo-8%Co-5%W-1%C-4,6Pb 90 75 26 Fe-10,bMo-8%Co 5%W-1%C-2%G 90 75 27 Fe-10%Mo~8~6Co-5%W~1~6C-4%Pb-2%G 9 76 :EXAMPIE 3 A reduced iron powder of -100 mesh, ~erromolybdenum (50 % Mo, 0 06 % C, 1.26 % Si) powder of -200 rnesh, tungsterl powder of -325 mesh? cobalt powder of -325 mesh, nickel car-~; ~ bonyl powder of -325 mesh, lead powder of -250 mesh and low melting point glass powder of 30%B203-30~oP205-3090PbO were 20 mixed so as to give each o~ the ~ollowing compositions, îormed in a density of 90 % and then sintered at 1130 C for 30 min-ute~3 in a reducing atmosphere:
: Sample Chemical Composition Densi-ty3~ardne.ss : No. (by weight. :Ee remainder) _ _ (%)_(BRB~
28 Fe-3,6Mo-2~Co--2%W-296Ni-0.l%a 90 73 - ~ ~ 29 Fe-5%Mo-89o'Co-8%W-3%Ni-1%C 90 79 Fe~ 6Mo-5%ao-3,~W-0.5/Ni-1%C 90 . 86 31 Fe~ oMo-8%ao~3%W-3%Ni-1%a 90 80 32 Fe-10%Mo-4%Co-5%W-6~6Ni~ a 90 78 33 Fe-15%Mo-12%Co-10%W-8/6Ni-2%a 90 84 34 Fe-10~oMo-8%Co-5%W-3%Ni-1%a-4%Pb 9 78 Fe~ Mo-8%Co-5%W-3~oNi- 1%C-2%G 90 79 36 Fe-10%Mo-8%Co-5%W-3%Ni-1~C-4%Pb-2%G 90 79 .
4~73se 1 ~he so obtained Samples 1 to 36 (~xampies 1-3) were worked or fini~hed in a predetermined size and then subjected to the ~ollowing durability test:
Test of Durabilit~
Using a 360 cc~ water-cooling, two c~linder- a~d two caburetterengine at 7500 rpm with ~ull throttle and full load~
the tappet gap was first adjusted to 0.1 m/m and a period of time was measured irre~pective of the right and left c~linders when the gap became zero. ~he life of a ring for the valve seat was de~ined by the measured period of time. A gasoline was used having an octane number of 87 and containing lead in a quar.tit~ of 0.002 g/gallon.
~he measured results are tabulated below:
~able 1 Durability_(hrs) Sample No~irst ~estSecond ~est ` 3 51 60 ~ 5 65 64 :
; - 11 89 82 16 186 , 178 _ 9 _ -~ii9L73~
. 148 151 26 1~7 131 .
29 96 g5 '. ~ . 30 96 . g8 31 ~5 101 :: . 33 126 132 .34 156 162 I~ ~ 36 206 211 :~; 2~ As is evident from these results, the sintered ferrous alloys ~ having bhe composition according to the present i~vention can : : :: ~
fa~ouxabl~ be compared i~ darability with the ~imilar Fe Mo alloys we had~proposed. I
.
Claims
1. A valve seat material for an internal combustion engine r which comprises a sintered ferrous alloy having the composition:
percent by weight molybdenum ............. 3 to 15 cobalt ............. 2 to 12 tungsten ............. 0.5 to 10 carbon ............. 0.1 to 2 nickel ............. 0 to 8 lead ............. 2 to 15 glass ............. 0.5 to 8 the remainder being iron except for usual impurities and trace elements.
percent by weight molybdenum ............. 3 to 15 cobalt ............. 2 to 12 tungsten ............. 0.5 to 10 carbon ............. 0.1 to 2 nickel ............. 0 to 8 lead ............. 2 to 15 glass ............. 0.5 to 8 the remainder being iron except for usual impurities and trace elements.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2569274A JPS50119705A (en) | 1974-03-07 | 1974-03-07 | |
| JP2569474A JPS5428828B2 (en) | 1974-03-07 | 1974-03-07 | |
| JP2569374A JPS5428827B2 (en) | 1974-03-07 | 1974-03-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1064739A true CA1064739A (en) | 1979-10-23 |
Family
ID=27285111
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA221,563A Expired CA1064739A (en) | 1974-03-07 | 1975-03-07 | Valve seat material for an internal combustion engine |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1064739A (en) |
| DE (1) | DE2509747C3 (en) |
| FR (1) | FR2263371B1 (en) |
| GB (1) | GB1445075A (en) |
| IT (1) | IT1060816B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU572425B2 (en) * | 1983-07-01 | 1988-05-05 | Sumitomo Electric Industries, Ltd. | Valve seat insert |
| US4671491A (en) * | 1984-06-12 | 1987-06-09 | Sumitomo Electric Industries, Ltd. | Valve-seat insert for internal combustion engines and its production |
| DE3607515A1 (en) * | 1986-03-07 | 1987-09-10 | Ringsdorff Werke Gmbh | METHOD FOR PRODUCING AN IMPERMEABLE SINTER BODY |
| EP0604773B2 (en) † | 1992-11-27 | 2000-08-30 | Toyota Jidosha Kabushiki Kaisha | Fe-based alloy powder adapted for sintering, Fe-based sintered alloy having wear resistance, and process for producing the same |
| GB2307917B (en) * | 1995-12-08 | 1999-03-17 | Hitachi Powdered Metals | Manufacturing process of sintered iron alloy improved in machinability,mixed powder for manufacturing modification of iron alloy and iron alloy product |
| US5819154A (en) * | 1995-12-08 | 1998-10-06 | Hitachi Powdered Metal Co., Ltd. | Manufacturing process of sintered iron alloy improved in machinability, mixed powder for manufacturing, modification of iron alloy and iron alloy product |
-
1975
- 1975-03-04 IT IT8361375A patent/IT1060816B/en active
- 1975-03-05 GB GB913875A patent/GB1445075A/en not_active Expired
- 1975-03-06 DE DE19752509747 patent/DE2509747C3/en not_active Expired
- 1975-03-06 FR FR7507071A patent/FR2263371B1/fr not_active Expired
- 1975-03-07 CA CA221,563A patent/CA1064739A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| AU7879775A (en) | 1976-09-09 |
| GB1445075A (en) | 1976-08-04 |
| DE2509747A1 (en) | 1975-09-18 |
| FR2263371B1 (en) | 1980-11-14 |
| IT1060816B (en) | 1982-09-30 |
| DE2509747C3 (en) | 1978-11-16 |
| FR2263371A1 (en) | 1975-10-03 |
| DE2509747B2 (en) | 1978-03-23 |
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