AU601249B2 - Gray cast iron having both increased wear resistance and toughness - Google Patents
Gray cast iron having both increased wear resistance and toughness Download PDFInfo
- Publication number
- AU601249B2 AU601249B2 AU82879/87A AU8287987A AU601249B2 AU 601249 B2 AU601249 B2 AU 601249B2 AU 82879/87 A AU82879/87 A AU 82879/87A AU 8287987 A AU8287987 A AU 8287987A AU 601249 B2 AU601249 B2 AU 601249B2
- Authority
- AU
- Australia
- Prior art keywords
- wear resistance
- cast iron
- iron
- product
- austenite
- 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.)
- Ceased
Links
- 229910001060 Gray iron Inorganic materials 0.000 title claims description 32
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 51
- 229910052799 carbon Inorganic materials 0.000 claims description 28
- 239000010439 graphite Substances 0.000 claims description 23
- 229910002804 graphite Inorganic materials 0.000 claims description 23
- 239000003795 chemical substances by application Substances 0.000 claims description 17
- 229910000859 α-Fe Inorganic materials 0.000 claims description 17
- 229910001566 austenite Inorganic materials 0.000 claims description 16
- 239000011159 matrix material Substances 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 15
- 239000000203 mixture Substances 0.000 claims description 15
- 238000010791 quenching Methods 0.000 claims description 15
- 238000010438 heat treatment Methods 0.000 claims description 13
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 12
- 239000007787 solid Substances 0.000 claims description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 9
- 230000005496 eutectics Effects 0.000 claims description 9
- 230000000171 quenching effect Effects 0.000 claims description 8
- 229910052710 silicon Inorganic materials 0.000 claims description 8
- 239000010703 silicon Substances 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 6
- 229910052759 nickel Inorganic materials 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 6
- 238000007711 solidification Methods 0.000 claims description 6
- 230000008023 solidification Effects 0.000 claims description 6
- 238000012360 testing method Methods 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000010949 copper Substances 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 5
- 229910052750 molybdenum Inorganic materials 0.000 claims description 5
- 239000010936 titanium Substances 0.000 claims description 5
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 4
- 239000011733 molybdenum Substances 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 241000765309 Vanadis Species 0.000 claims 1
- 210000002837 heart atrium Anatomy 0.000 claims 1
- MYWUZJCMWCOHBA-VIFPVBQESA-N methamphetamine Chemical compound CN[C@@H](C)CC1=CC=CC=C1 MYWUZJCMWCOHBA-VIFPVBQESA-N 0.000 claims 1
- 239000011572 manganese Substances 0.000 description 12
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 11
- 238000005266 casting Methods 0.000 description 11
- 229910052748 manganese Inorganic materials 0.000 description 11
- 229910001018 Cast iron Inorganic materials 0.000 description 10
- 230000015572 biosynthetic process Effects 0.000 description 9
- 229910001562 pearlite Inorganic materials 0.000 description 7
- 235000000396 iron Nutrition 0.000 description 6
- 239000003570 air Substances 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 5
- 229910000734 martensite Inorganic materials 0.000 description 5
- 229910052804 chromium Inorganic materials 0.000 description 4
- 239000011651 chromium Substances 0.000 description 4
- 150000001247 metal acetylides Chemical class 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 229910052720 vanadium Inorganic materials 0.000 description 4
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 3
- 238000005275 alloying Methods 0.000 description 3
- 238000013016 damping Methods 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 238000005087 graphitization Methods 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- -1 iron carbides Chemical class 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 239000003643 water by type Substances 0.000 description 2
- 229910001339 C alloy Inorganic materials 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- 229910021588 Nickel(II) iodide Inorganic materials 0.000 description 1
- 229910000805 Pig iron Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 229920001074 Tenite Polymers 0.000 description 1
- 241001122767 Theaceae Species 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000011081 inoculation Methods 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- QMQXDJATSGGYDR-UHFFFAOYSA-N methylidyneiron Chemical compound [C].[Fe] QMQXDJATSGGYDR-UHFFFAOYSA-N 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- BFSQJYRFLQUZKX-UHFFFAOYSA-L nickel(ii) iodide Chemical compound I[Ni]I BFSQJYRFLQUZKX-UHFFFAOYSA-L 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D5/00—Heat treatments of cast-iron
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Description
L.J. DYSON Registered Patent Attorney THE COMMISSIONER OF PATENTS.
Edwd. Waters Sons.
Melbourne.
COMMONWEALTH OF AUSTRAL 0 1 4 t ^f PATENTS ACT 1952-69 COMPLETE SPECIFICATION
(ORIGINAL)
Class Int. Class Application Number: Lodged: 4* Complete Specification Lodged: Accepted: Published: Priority Related Art Related Art: 4 Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: FORD MOTOR COMPANY OF CANADA, LIMITED The Canadian Road, Oakville, Ontario, Canada.
BELA VICTOR KOVACS EDWD. WATERS SONS, 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.
Complete Specification for the invention entitled: GRAY CAST IRON HAVING BOTH INCREASED WEAR RESISTANCE AND TOUGHNESS The following statement is a full description of this invention, including the best method of performing it known to us 1.
61h..- To: The Commissioner of Patents.
I-R 69- I GRAY CAST IRON HAVING BOTH INCREASED WEAR RESISTANCE AND TOUGHNESS Background of the Invention Technical Field The invention relates to the art of making gray cast iron and, more particularly, to the technology Description of the Prior Art "o iv Gray cast iron is the least expensive of all the 15 cast metals. This is due to the type of raw materials used: pig iron, cast iron scrap; steel scrap, limestone, coke and air, all of which are relatively inexpensive.
Most gray cast iron used commercially is used primarily in the as-cast condition. There has been some attention 0 tT to heat treatment and low alloying for gray cast irons through the years.
The general concensus of foundry operators in this country indicates that the composition of gray cast iron should be about (using weight percentages here and throughout the description): 2.0-4.0 carbon; 1.25-3.25 silicon; .75-1.25 manganese; .08-.12 sulfur; and .07-.20 phosphorus.
In the field of abrasive wear, gray cast iron is usually used where the required impact toughness in I 30 service is not severe. Such cast iron is resistant to abrasive wear because of the presence of a high amount of carbides in the matrix of the cast iron. Most gray cast irons will contain at least 10% by weight primary complex :i -2iron carbides. Unfortunately, however, these carbides are normally massive and impart a degree of brittleness to the cast iron which considerably limits its usefulness with reference to impact strength. While relegating gray cast iron to applications without the need for hig'i impact strength, the main developmental effort has been to improve machining.
One attempt to provide greater machinability while retaining excellent wear resistance and fatigue i0 resistance of gray cast irons involves heat treating the as-cast iron to reduce hardness while retaining the carbidic microstructure (see U.S. patent 4,230,506). In this patent, the cast metal was alloyed with a combination of carbide forming agents such as chromium, nickel, copper, molybdenum, and vanadium. They were used in combination to provide a composite total in an amount of 2.25-3.85%; this is a considerable amount of carbide forming agent. The improvement in machinability was achieved by heat treating to an austenitizing temperature, slowly cooling over a period of 1-1/2 hours to a temperature level of 400 0 F, and then air cooling.
Slow cooling promoted the production of pearlite and reduced the hardness of such cast iron, making it more readily machinable. After machining, the iron was quenched to transform any retained austenite to martensite.
The problem with the 4,230,506 patent is that wear resistance is retained or improved at the sacrifice of toughness and strength characteristics, making it unsuitable for applications that require a high level for both of these characteristics.
Similarly, in U.S. patent 3,384,515, the solution to the problem of machinability was to control heat treating to permit the promotion of complex iron carbides while providing for incipient spheroidization of
A
r 3 :;ii~ 3 pearlite, thereby avoiding martensite and reducing the hardness of the material. The same problem with respect to lack of enhancement of toughness and strength characteristics in such a carbidic cast iron remains.
In U.S. patent 2,885,284, an attempt was made to provide for an increase in both the abrasive wear as well as the impact properties of the gray cast iron. The Icontribution of this patent is to incorporate high r amounts of alloying ingredients in the form of aluminum and manganese to promote contrary characteristics.
Aluminum is added in amounts greater than 1% to promote graphitization and manganese is added in amounts greater than 1.5% to promote carbide stabilization. There is no attempt to modify or introduce any unusual heat treating parameters; there is simply a reliance upon conventional processing and heat treating steps. The disclosure i admits, in column 2, lines 27-33, that the amount of t aluminum or manganese that is incorporated will depend c upon which characteristic is desired in the final t t product, namely, to increase toughness the carbon must be predominantly in the form graphite promoted by the use of aluminum,-and to provide for increased hardness the carbon must be predominantly in the form of carbides, which is promoted by the incorporation of manganese.
This disclosure is an "either/or" teaching in that the there is no suggestion that both of such characteristics can be achieved at a high level at the same time.
It is an object of this invention to provide a gray cast iron having both increased wear resistance and i 30 toughness which can be achieved by modification both in the chemistry and the heat treating techniques for gray cast iron.
In addition, it is an object of this invention to provide the above type of gray cast iron which additionally has high tensile strength, high damping
I
rmu*sr~ 4 capacity, high heat conductivity, and more ductility than conventional cast irons.
Summary of the Invention The above objects have been achieved by development of chemistry and process controls which disperse a predetermined mixture of eutectic carbide particles and flake graphite throughout a matrix of high carbon austenite and ferrite.
i 10 The invention specifically is a method comprising: solidifying a hypoeutectic gray iron melt to which has been added a carbide forming agent in an I amount of by weight, selected from the group consisting of Ti, V, Cr, and Mo and, advantageously, a high carbon austenite-ferrite forming agent in an amount of by weight, selected from the group consisting of nickel and copper and (ii) at a solidification rate to form a matrix with a mixture of flake graphite and Seutectic carbide suspended in the matrix; and heat treating the solid by heating to a temperature and I for a period of time to fully austenitize the solid and (ii) quenching the solid to a temperature level and for a period of time to decompose austenite to form a high carbon austenite and ferrite matrix, I ar c-oo\\' The hypoeutectic gray iron contains less than 4.35% carbon equivalent and preferably comprises, by weight, 2.5-3.0% carbon, 2.0-2.5% silicon, .5-.90% manganese, and the remainder iron.
Preferably, the heat treating comprises heating to a temperature level of 1560-1590 0 F for a period of time of 1.5-2.5 hours; and the quenching step comprises quenching to a temperature level of 450-800°F for a period of time of 1.5-2.5 hours. The rate at which such quenching is carried out is preferably in the range of 300-375F per minute.
1
I
Ir a S 4 It S t S 54 5 The resultant cast iron will comprise a microstructure preferably having the suspended mixture comprised of 40-60% flake graphite and the remainder of the mixture eutectic carbide. Such mixture is controlled by the selection of the solidification rate and by the selection of chemistry for the gray cast iron melt. The casting will preferably have a tensile strength of 45-55 ksi, an impact strength of 30-35 ft. lb, and an elongation of about The wear resistance of such casting is 2-3 times greater than conventional gray cast irons and when measured by a standard sleeve test is .0028-.0019 inch per 1000 hours. The casting also is characterized by resistance to scuffing whereby the ratio of horsepower to produce scuffing divided by the normal horsepower is greater than 1.5. These wear resistance parameters are achieved through attainment of a type A graphite flake in the casting.
Summary of the Drawings Figure 1 is a photo-micrograph of the structure of the casting produced by the method of this invention, the microstructure being shown at an enlargement of 500X. Areas of flake graphite, eutectic carbide, and austenite ferrite are indicated.
:1 :1 r S At 954* Detailed Description and Best Mode The preferred method for making a gray cast iron having both increased wear resistance and impact toughness comprises: solidifying a hypoeutectic gray iron melt to which has been added a carbide forming first agent in an amount of by weight, selected from the group consisting of titanium, vanadium, chromium, and molybdenum, and a second agent to facilitate the formation of high carbon austenite-ferrite, said second agent being present in an c~ ~~ia 6 amount of by weight, selected from the group consisting of nickel and copper and (ii) at a solidification rate to form a matrix with a mixture of flake graphite and eutectic carbide suspended in the matrix; and heat treating the solid by heating to a temperature and for a predetermined period of time to fully austenitize the solid (ii) quenching the solid to a temperature level and for a period of time to decompose austenite to form a high carbon austenite-ferrite matrix and (iii) air cooling the solid.
,Chemistry A conventional wear resistant gray iron usually contains 3.0-4.0% carbon, 1.5-3.0% silicon, and .5-.9 manganese. This method lowers the carbon content and o ^adds both a carbide forming agent and an agent to S, facilitate the formation of high carbon austenite-ferrite o during heat treatment. The carbide forming agent is made o in addition to the normal carbide forming tendencies of manganese which is a normal part of gray cast iron.
Aluminum is specifically absent from the present .I chemistry because it is a graphitizer which works against carbide formation and encourages pin hole defects. The addition .of a graphitizing agent is conspicuously absent from the present invention because graphitization can be controlled through process parameters with a given lower amount of ca-bon.
Specifically, the chemistry comprises, preferably, 2.5-3.0% by weight carbon (a hypoeutectic iron-carbon alloy would comprise less than 35% carbon equivalent). If the carbon content were to be below it would be difficult to provide the desired amount of carbide/graphite ratio (40:60 to 60:40) that is necessary for the wear resistance of this invention. If the carbon content were in excess of processing 7 parameters would tend to form an excessive amount of graphite. It is desirable for the starting melt for this invention that it have a carbon equivalent in the range of 3.2-4.35 because below 3.2 too much carbide is formed, and above 4.35 too much graphite is formed, making it difficult to control the graphite/carbide ratio. Silicon is present in an amount of 2.0-2.5% and manganese remains at If the silicon and manganese contents were to be below the designated amounts of 2.0 and i°o. 10 respectively, there would be insufficient volumes of graphite or carbide formation; if the upper limit of manganese was exceeded, Mn segregation will occur and a nonuniform matrix structure will result. If the.upper limit of silicon is exceeded, excessive carbide and/or graphite formation will occur.
The additional carbide forming agent, which is o Sadded to the gray iron melt herein, comprises molybdenum, titanium, chromium, or vanadium. Any one or all of these ingredients may be added as long as they are present in the alloy melt in an amount in the range of as combined. If less than is employed, the carbide volume will be too low; if greater than is employed, then too much carbide will be present.
In order to promote the decomposition of austenite into high carbon austenite and ferrite, without the formation of pearlite or martensite, during the heat treatment and cooling sequence, it is desirable to add either nickel and/or copper in an amount of which functions as a pearlite suppressor and thus an austenite-ferrite former. If the amount of these elements, singly or combined, were to be below then pearlite formation in larger castings will occur, and if exceeding the alloying agent would be wated and is uneconomical.
The above melt is fully solidified at a rate I t rrt 8 over a period of 4-16 minutes to ensure the formation of a carbon mixture in the form of 40-60% by volume graphite and the remainder eutectic carbide.
Processing The solidification of the melt as indicated above is then subjected to a heat treatment sequence which comprises heating to an austenitizing temperature in the range of 1560-1590'F (848.9-865.6 0 C) and held at 10 such temperature for a period of 1.5-2.5 hours, during which time the casting will be fully austenitized. The casting is then quenched to a temperature level of 450-800°F and held for a period of 1.5-2.5 hours. The quench rate should be in the range of 300-375 0 F per minute. If the quench rate were to be slower than 300°F per minute, the opportunity for formation of pearlite would be increased. If the quench rate were to exceed 375 0 F per minute, the tendency for forming quenching cracks (due to high thermal stresses) would be experienced. The quench rate is important because it attempts, by way of processing, to determine the desirable matrix of austenite and ferrite. By observing the quench rate and the required chemistry, such heat treatment sequence will result in a cast iron matrix of austenite-ferrite having a suspended carbon mixture in the form of 40-60% flake graphite and the remainder in the form of eutectic carbide particles. This pro ortioned mixture is one of the key aspects of providing for simultaneous enhancement of wear resistance and impact resistance.
Following the decomposition of austenite to high carbon austenite and ferrite, the casting or solidification is then cooled to room temperature by air cooling.
1~ o ar o o, Do 0 00 0 0) 00 0 9 Microstructure The resulting casting will have a microstructure which consists of a high carbon au.tenite and ferrite matrix with a suspended mixture of flake graphite and eutectic carbide particles. There is a conspicuous absence of martensite or pearlite in the microstructure. The suspended mixture particles constitute about 20% by volume of the microstructure. The graphite particles will be in the form of type A flake graphite because of good inoculation using ferro-silicone. Such type A graphite will influence the damping capacity, thermal conductivity, and machinability of the gray cast iron.
The physical characteristics of such gray cast iron S will have a wear resistance which is at least 2-3 times 15 greater than that of conventional gray cast irons, and with the limited samples that have been tested to date the wear resistance shows .0028-.0019 inch per 1000 hours of a S conventional sleeve test, such test being outlined in the Metals Handbook.
In addition, the wear resistance is characterized by resistance to scuffing wherein the ratio of horsepower to produce scuffing divided by the normal horsepower is greater than 1.5. Gray cast iron, having a type A graphite in a S martensitic matrix, normally exhibits a resistance to scuffing in the range of 1.39-1.45.
C-s' a. C-VN LsE).
The impact resistance was Eested to be in the range of 25-35 ft.lbf, where a conventional gray cast iron has a charpy notch impact value normally in the range of 1-2 ft.lbf. The v-notch used for the test had a 450 included angle, a 0.079 depth, and a 0.010 radius at the bottom of the notch.
The tensile strength of such resultant cast iron is 45-55 ksi, which is in the high range for gray cast iron, and elongation of The hardness for such material is the range of 160-248 BHN.
eaC 0006 *aad a 4 10 Examples Several examples were prepared by melting a gray iron starting material which consisted of silicon in an amount of manganese with phosphorus being and sulphur being The carbon content of the gray iron was varied according to that sh-,/n in Table I along with variations in the added carbide forming agent, and variations in the addition of nickel as an agent to 4 encourage the decomposition of austenite to high 0 austenite and ferrite. Heat Treatment was employed as indicated (such treatment being to heat the casting to 1570 0 F for two hours, quench to 600 0 F, and hold for two 4 hours, then air cool). The wear resistance and impact resistance were recorded for each such example.
While various enx-a h -we £-tae.
been illustrated and described, it will be o-a us to those skilled in the art that vario anges and modifications may be made -iout departing from the invention, and jb'-intended to cover in the appended claims- such changes and equivalents as fall within -true sp rint -and scope of the inetion.
j -4 4 ,*Q a tea S S S S I S C C C 14*5 4 4 TABLE I: C arbo n Content Sample Carbide Former Additive None Austenite! Ferrite Promoter None Heat Treatment Applied No Wear Resistance Poor Impact Resistance (ft. lbE) 2 Mo. .5 Yes Moderate to Good NiI2. 0 Good V. 5 MoI. 5 Ti/. 1 Mo! .1 tv Very Good Good Poor Poor 32 1 (damping very low) 3 None
Claims (6)
1. A method of making a more wear resistant gray cast iron with high wear resistance and impact strength, comprising: solidifying a hypoeutectic gray iron melt to which has been added a carbide forming first agent in an amount of by weight, selected from the group consisting of titanium, vanadi.um, and molybdenum, said solidification being at a rate to form a matrix with a 10 mixture of flake graphite and eutectic carbide suspended in said matrix; and heat treating said solid by heating to a temperature and for a period of time to fully aus-.enitize the solid, (ii) quenching said solid to a 15 predetermined temperature level and holding at said level for a period of time to decompose austenite to form a high carbon austenite and ferrite matrix, (iii) air cooling the solid to room temperature.
2. The method as in claim 1, in which said solidifying step additionally comprises adding a high carbon austenite-ferrite forming agent in an amount of selected from the group consisting of nickel and copper.
3. The method as in claim 1, in which said hypoeuctectic iron contains less than 4.35% carbon equivalent.
4. The method as in claim 1, in which said hypoeutectic gray iron melt comprises, by weight, 2.5-3.0% carbon, 2.0-2.5% silicon, manganese, and the remainder iron. The method as in claim 1, in which said step comprises heating to 1560-1590 0 F for 1.5-2.5 hours.
6. The method as in claim 1, in which step comprises quenching to a temperature level of
450-800OF for 1.5-2.5 hours. 7. is 3 8. comp mixt 9. meth stre ft. 1 char than 11. resi test Art Ar A AIII r a. *r a a atr At A A Al W~OI b *i 4. 4.4 L V 12. resi scuf 13. for WATE The 1 1wt. AUST LJD/j 13 7. The method as in claim 6, in which said quench rate is 300-3750F/minute. 8. The method as in claim 1, in which said mixture is comprised of 40-60% flake graphite and the remainder of said mixture being eutectic carbide particles. 9. The product resulting from the practice of the method of claim 1, which is characterized by a tensile strength of 40-50 ksi, and an impact strength of 30-35 ft.lbf. The product as in claim 9, which is further S*characterized by wear resistance which is 2-3 times greater than that of conventional gray cast iron. t S, 11. The product as in claim 10, in which said wear resistance is .0019-.0028 inch per 1000 hours of sleeve I test. 12. The product as in claim 10, in which said wear resistance is further characterized by a resistance to scuffing ratio greater than 13. The product as in claim 9, in which the graphite for said product is in the type A form. DATED this 14th day of March, 1990 FORD MOTOR COMPANY OF CANADA, LIMITED WATERMARK PATENT TRADEMARK ATTORNEYS, "The Atrium", 290 Burwood Road Hawthorn, Victoria, 3122 AUSTRALIA LJD/AGB:JJC (3/20)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US945145 | 1978-09-22 | ||
| US94514586A | 1986-12-22 | 1986-12-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU8287987A AU8287987A (en) | 1988-06-23 |
| AU601249B2 true AU601249B2 (en) | 1990-09-06 |
Family
ID=25482696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU82879/87A Ceased AU601249B2 (en) | 1986-12-22 | 1987-12-21 | Gray cast iron having both increased wear resistance and toughness |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0272788B1 (en) |
| JP (1) | JPS63166929A (en) |
| AU (1) | AU601249B2 (en) |
| CA (1) | CA1311993C (en) |
| DE (1) | DE3780138T2 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0272788B1 (en) * | 1986-12-22 | 1992-07-01 | Ford Motor Company Limited | A method of making wear resistant gray cast iron |
| US5242510A (en) * | 1992-09-25 | 1993-09-07 | Detroit Diesel Corporation | Alloyed grey iron having high thermal fatigue resistance and good machinability |
| GB9718982D0 (en) * | 1997-09-09 | 1997-11-12 | T & N Technology Ltd | Disc brake rotor |
| US6395107B1 (en) * | 2000-01-28 | 2002-05-28 | Sundaresa V. Subramanian | Cast iron for use in high speed machining with cubic boron nitride and silicon nitride tools |
| DE10064248A1 (en) | 2000-12-22 | 2002-07-04 | Zf Sachs Ag | Cast iron alloy for a friction element of a friction clutch and friction element for a friction clutch |
| CN102211178B (en) * | 2011-04-14 | 2013-09-18 | 河北坤腾泵业有限公司 | Composite suspending agent for producing roller sleeve and disc lining of vertical mill |
| ITUB20152456A1 (en) * | 2015-07-24 | 2017-01-24 | Zanardi Fond S P A | PROCEDURE FOR THE PRODUCTION OF MECHANICAL COMPONENTS IN LAMELLAR IRON OR VERMICULAR. |
| CN109609737B (en) * | 2018-12-13 | 2020-09-25 | 苏州东海玻璃模具有限公司 | Method for eliminating stress of vermicular graphite cast iron glass mold |
| CN113337686B (en) * | 2021-05-31 | 2022-02-18 | 东风商用车有限公司 | Engine cylinder cover and preparation method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0018703A2 (en) * | 1979-05-06 | 1980-11-12 | Textron Inc. | Camshaft manufacturing process |
| AU8287987A (en) * | 1986-12-22 | 1988-06-23 | Ford Motor Company Of Canada Limited | Gray cast iron having both increased wear resistance and toughness |
| AU577616B2 (en) * | 1984-09-04 | 1988-09-29 | Ford Motor Company Of Canada Limited | Cg cast iron |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR89010E (en) * | 1967-07-19 | |||
| GB545102A (en) * | 1940-05-30 | 1942-05-11 | Mond Nickel Co Ltd | Improvements relating to cast iron |
| GB840490A (en) * | 1957-06-06 | 1960-07-06 | Goetzewerke | Improvements relating to the manufacture of piston rings |
| US3384515A (en) * | 1965-06-21 | 1968-05-21 | Gen Motors Corp | Process of preparing improved cast iron articles |
| JPS55128563A (en) * | 1979-03-28 | 1980-10-04 | Nissan Motor Co Ltd | Cast iron excellent in wear and seizure resistance |
| JPS6052515A (en) * | 1983-09-01 | 1985-03-25 | Hitachi Metals Ltd | Manufacture of tough and hard gray cast iron |
| JPS6119759A (en) * | 1984-07-05 | 1986-01-28 | Toyota Motor Corp | Abrasion resistant cast iron |
-
1987
- 1987-11-13 EP EP87310035A patent/EP0272788B1/en not_active Expired - Lifetime
- 1987-11-13 DE DE19873780138 patent/DE3780138T2/en not_active Expired - Lifetime
- 1987-11-24 JP JP29593687A patent/JPS63166929A/en active Pending
- 1987-11-27 CA CA000553034A patent/CA1311993C/en not_active Expired - Lifetime
- 1987-12-21 AU AU82879/87A patent/AU601249B2/en not_active Ceased
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0018703A2 (en) * | 1979-05-06 | 1980-11-12 | Textron Inc. | Camshaft manufacturing process |
| AU577616B2 (en) * | 1984-09-04 | 1988-09-29 | Ford Motor Company Of Canada Limited | Cg cast iron |
| AU8287987A (en) * | 1986-12-22 | 1988-06-23 | Ford Motor Company Of Canada Limited | Gray cast iron having both increased wear resistance and toughness |
Also Published As
| Publication number | Publication date |
|---|---|
| CA1311993C (en) | 1992-12-29 |
| EP0272788B1 (en) | 1992-07-01 |
| DE3780138D1 (en) | 1992-08-06 |
| EP0272788A1 (en) | 1988-06-29 |
| AU8287987A (en) | 1988-06-23 |
| DE3780138T2 (en) | 1993-02-11 |
| JPS63166929A (en) | 1988-07-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Davis | ASM specialty handbook: cast irons | |
| EP1384794B1 (en) | Spheroidal cast iron particulary for piston rings and method for its production | |
| US2485760A (en) | Cast ferrous alloy | |
| US4596606A (en) | Method of making CG iron | |
| US8333923B2 (en) | High strength gray cast iron | |
| Sckudlarek et al. | Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium | |
| US6258180B1 (en) | Wear resistant ductile iron | |
| US4891076A (en) | Gray cast iron having both increased wear resistance and toughness | |
| Stefanescu | Classification and basic metallurgy of cast iron | |
| JP7369513B2 (en) | Spheroidal graphite cast iron alloy | |
| Hsu et al. | Influence of stepped austempering process on the fracture toughness of austempered ductile iron | |
| AU601249B2 (en) | Gray cast iron having both increased wear resistance and toughness | |
| US4541878A (en) | Cast iron with spheroidal graphite and austenitic-bainitic mixed structure | |
| KR101883290B1 (en) | Method for manufacturing for austempered ductile cast iron | |
| JPS58185745A (en) | Spherical graphite cast iron parts and their manufacture | |
| US4475956A (en) | Method of making high strength ferritic ductile iron parts | |
| Davis | Classification and basic metallurgy of cast irons | |
| JPH0238645B2 (en) | KOKYODOKYUJOKOKUENCHUTETSUNOSEIZOHOHO | |
| Lee et al. | Influence of casting size and graphite nodule refinement on fracture toughness of austempered ductile iron | |
| US4547221A (en) | Abrasion-resistant refrigeration-hardenable ferrous alloy | |
| US4867804A (en) | Manufacturing process of toughened bainitic nodular graphite cast iron | |
| Mourad et al. | Effect of copper addition on microstructure and mechanical properties of ductile cast iron | |
| JPS6196054A (en) | Spheroidal graphite cast iron and manufacture thereof | |
| JPS5867844A (en) | Spherical graphite cast iron excellent in tenacity and preparation thereof | |
| JP2567258B2 (en) | Iron-based casting having high strength, high rigidity, and high toughness, and a method for producing the same |