US2899346A - Cast iron heat - Google Patents
Cast iron heat Download PDFInfo
- Publication number
- US2899346A US2899346A US2899346DA US2899346A US 2899346 A US2899346 A US 2899346A US 2899346D A US2899346D A US 2899346DA US 2899346 A US2899346 A US 2899346A
- Authority
- US
- United States
- Prior art keywords
- casting
- temperature
- heat
- subjecting
- order
- 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 - Lifetime
Links
- 229910001018 Cast iron Inorganic materials 0.000 title description 8
- 238000005266 casting Methods 0.000 claims description 66
- 238000010791 quenching Methods 0.000 claims description 22
- 230000000171 quenching Effects 0.000 claims description 22
- 229910000734 martensite Inorganic materials 0.000 claims description 14
- 238000010899 nucleation Methods 0.000 claims description 12
- 238000005087 graphitization Methods 0.000 claims description 10
- 150000002500 ions Chemical class 0.000 claims 4
- 229910001037 White iron Inorganic materials 0.000 description 20
- 238000001816 cooling Methods 0.000 description 20
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 20
- 238000005496 tempering Methods 0.000 description 12
- 238000000034 method Methods 0.000 description 10
- 229910052742 iron Inorganic materials 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 229910052799 carbon Inorganic materials 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 206010054107 Nodule Diseases 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 230000003111 delayed Effects 0.000 description 2
- 238000005755 formation reaction Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
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
- 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
Definitions
- the invention relates to improvements in the heat treatment of white cast iron parts which are graphitised by subsequent annealing. It relates more particularly to the process which consists of the following cycle of treatment comprising three phases:
- the process can also be applied to thin parts (i.e. less than 10 mm.) of complicated shape cast in chill moulds with or without pressure. It applies in this case more particularly to the following cast iron composition:
- a method of heat treating whiteiron castings which comprises subjecting a casting of said white iron to austenization with heat at a temperature of approximately 840 C., cooling the casting in still air sufliciently for the surface temperature of the casting to cool to a temperature in the order of 650 C. to 700 C., quenching the casting to form martensite, subjecting the casting to nucleation tempering with heat at a temperature in the order of 450 C., subjecting the casting to graphitization with heat at a temperature between 800 C. to 950 C. for a period of time in the order of two hours.
- a method of heat treating white iron castings which comprises subjecting a casting of said white iron to austenization with heat at a temperature of approximately 840 C. for a period of time in the order of 20 minutes to 1 hour and 30 minutes, cooling the casting in still air sufliciently for the surface temperature of the casting to cool to a temperature in the order of 650 C. to 700 C., quenching the casting to form martensite, subjecting the casting to nucleation tempering with heat at a temperature of approximately 450 C., cooling the casting in still air, subjecting the casting to graphitization with heat at a temperature between 800 C. to 950 C. for a period of time in the order of two hours.
- a method of heat treating white iron castings which comprises, subjecting a casting of said white iron to l austenization of approximately 840 C. for approximately one hour, cooling the casting in still air sufliciently for the surface temperature of the casting to cool to a temperature in the order of 650 C. to 700 C., quenching the casting in oil to form martensite, subjecting the casting to nucleation tempering with heat at a temperature of substantially 440 C. for 4 to 5 hours, subjecting the casting to graphitization with heat at a temperature of about 920 C. for about two hours.
- a method of heat treating white iron castings which comprises,- subjecting a"casting of said white iron to austenization of approximately 840 C. for less than one hour, cooling the-casting in still airsufliciently for the surface temperature "of the casting to' cool to a temperatu'rein the order of 650 C. to 700 C., quenching the casting in oil to form martensite, subjecting the casting to'nucleation tempering with heat at a temperature of substantially-440 C. for 4 to'5 hours, s nbjecting the casting to graphitization with heat at atemperature of about 920 C. for about 2 hours, cooling the casting in still air. 1
- iron has the composition: 2%'C, 1% Mn, 1.5% Si, 1.35% V
Description
No Drawing. a plication February 15, 1955 I Serial .No. 488,428
Claims priority, application Francefripiil 9 *6 elm-ms. rei ns-11:8;
The invention relates to improvements in the heat treatment of white cast iron parts which are graphitised by subsequent annealing. It relates more particularly to the process which consists of the following cycle of treatment comprising three phases:
(1) Austenitization followed by interrupted martensitic quenching;
(2) Tempering and nucleation of the graphite at a precise temperature of the order of 450 C., variable according to composition;
(3) Subsequent graphitisation at high temperature (generally between 800 C. and 950 C.).
This process leads to difliculties in the case of the treatment of heavy pieces whose diameters may be as much as and exceed 4 to 7 cm., such as crank-shafts for motor cars, due to the size of the salt baths which are necessary and the difliculty of obtaining an adequate cooling speed to obtain the quasimartensitic structure.
According to the invention it has been foundthat it is possible to obtain good results in the series production of such parts cast in the white state, even in core sand or in shells, without the risk of shrinkage cracks in spite of the size and shape of the parts, if, after the austenitization has taken place at a suitable temperature: between 780 and 880 C. during a period of time sufficient for the homogeneisation of temperature and structural equilibrium to take place (20 minutes to 1 hour 30 minutes), the part is then subjected to a cooling operationin still air until the surface is lowered to a temperature of between 650 C. and 700 C. (or approximately 680 C. to 780 C. at the centre), before being immersed in the hot or cold oil or water quenching tank. This definition of intermediate cooling is characterised by the fact that in those regions of the part which have been cooled to the greatest extent the structure has remained austenitic and is yet able to be hardened by martensitic quenching by immersion in the quenching medium.
It should be noted that by using this delayed quenching with white cast iron parts, it is possible to prevent the formation of shrinkage cracks with perfect reliability.
This process applies particularly to the following cast iron:
Cu Ni 8 P Zr Ti Al I with or without intermediate-cooling, .the: castings a:
2,899,346 e nt brought to 920- C.=-f6r2 hours and are .then cooled'f -J l .1 a The! following :feature's are thus obtained:
flotal absencepf primary cementite-;..
:"Numberbf graphite nodules .iper square millimetre: 2.000to 6.000; Traction eharacteristics: JR= to 4100 'rkgt-lmm a. AZPercent S to -7 f (according-to the French nbrmsrfor 'steels); p" Endurance limit in rotary bending test: E36 iltgt/mmth.
If necessary, after the graphitisation at 920 it'tis possible toscarry ounaspartiar or total: graphitisationof theqaearliteshetween GSOTCJ'andflOOB'G-Jon tolbarlzywut a quality treatment comprising quenching and tempering or to carry out a surface hardening operation.
The process can also be applied to thin parts (i.e. less than 10 mm.) of complicated shape cast in chill moulds with or without pressure. It applies in this case more particularly to the following cast iron composition:
till
0 Mn Si Cu S P Ti Al R=80 to kg./mm. A percent=5 to 7% I claim:
l. A method of heat treating whiteiron castings which comprises subjecting a casting of said white iron to austenization with heat at a temperature of approximately 840 C., cooling the casting in still air sufliciently for the surface temperature of the casting to cool to a temperature in the order of 650 C. to 700 C., quenching the casting to form martensite, subjecting the casting to nucleation tempering with heat at a temperature in the order of 450 C., subjecting the casting to graphitization with heat at a temperature between 800 C. to 950 C. for a period of time in the order of two hours.
2. A method of heat treating white iron castings which comprises subjecting a casting of said white iron to austenization with heat at a temperature of approximately 840 C. for a period of time in the order of 20 minutes to 1 hour and 30 minutes, cooling the casting in still air sufliciently for the surface temperature of the casting to cool to a temperature in the order of 650 C. to 700 C., quenching the casting to form martensite, subjecting the casting to nucleation tempering with heat at a temperature of approximately 450 C., cooling the casting in still air, subjecting the casting to graphitization with heat at a temperature between 800 C. to 950 C. for a period of time in the order of two hours.
3. A method of heat treating white iron castings which comprises, subjecting a casting of said white iron to l austenization of approximately 840 C. for approximately one hour, cooling the casting in still air sufliciently for the surface temperature of the casting to cool to a temperature in the order of 650 C. to 700 C., quenching the casting in oil to form martensite, subjecting the casting to nucleation tempering with heat at a temperature of substantially 440 C. for 4 to 5 hours, subjecting the casting to graphitization with heat at a temperature of about 920 C. for about two hours.
" '4. A'process as defined in claim 3, wherein the cast iron has the composition: 2% C, 1% Mn, 1% Si, 1.35% Cu, 0.75% Ni, 0.05% S, 0.05% P, 0.15% Zr, 0.03% Ti, 0.06% Al, the balancebeing iron.
-5. A method of heat treating white iron castings which comprises,- subjecting a"casting of said white iron to austenization of approximately 840 C. for less than one hour, cooling the-casting in still airsufliciently for the surface temperature "of the casting to' cool to a temperatu'rein the order of 650 C. to 700 C., quenching the casting in oil to form martensite, subjecting the casting to'nucleation tempering with heat at a temperature of substantially-440 C. for 4 to'5 hours, s nbjecting the casting to graphitization with heat at atemperature of about 920 C. for about 2 hours, cooling the casting in still air. 1
" 6.A' 'rocess as defined in claim 3, wherein the cast 4 Cu, 0.05% S, 0.05% P, 0.05% Ti, 0.05% Al, the balance being iron.
References Cited in the file of this patent 5 UNITED STATES PATENTS 2,077,116 Lauenstein-u; Apr. 13, 1937 2,185,894 Hultgren Jan. 2, 1940 2,331,886 Boegehold Oct. 19, 1943 2,501,059 Kluijtmans Mar. 21, 1950 Hune Sept. 8, 1953 OTHER REFERENCES Materials and Methods, vol. 32, issue 6, December 1950, pages 50-53. 15 Rehder: The Iron Age, Ian. 17, 1952, pages 89-93.
iron has the composition: 2%'C, 1% Mn, 1.5% Si, 1.35% V
Claims (1)
1. A METHOD OF HEAT TREATING WHITE ION CASTING WHICH COMPRISES SUBJECTING A CASTING OF SAID WHITE ION TO AUSTENIZATION WITH HEAT AT A TEMPERATURE OF APPROXIMATELY 840*C., COOLING THE CASTING IN STILL AIR SUFFICEINTLY FOR THE SURFACE TEMPERATURE OF THE CASTING TO COOL TO A TEMPERATUARE IN THE ORDER OF 650*C. TO 700*C., QUENCHING THE CASTING TO FORM MARTENSITE, SUBJECTING THE CASTING TO NUCLEATION TEMPERATURE WITH HEAT AT A TEMPERATURE IN THE ORDER OF 450*C., SUBJECTING THE CASTING TO GRAPHITIZATION WITH HEAT AT A TEMPERATURE BETWEEN 800*C. TO 950*C. FOR A PERIOD OF TIME IN THE ORDER OF TWO HOURS.
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2899346A true US2899346A (en) | 1959-08-11 |
Family
ID=3448149
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US2899346D Expired - Lifetime US2899346A (en) | Cast iron heat |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2899346A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3005736A (en) * | 1958-02-06 | 1961-10-24 | Renault | High-toughness cast-iron for relatively thick castings, and method of producing same |
| US4299622A (en) * | 1978-11-06 | 1981-11-10 | Sony Corporation | Magnetic alloy |
| US4911763A (en) * | 1988-07-15 | 1990-03-27 | Norcast Corporation | Process for producing a low alloy white cast iron |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2077116A (en) * | 1933-04-07 | 1937-04-13 | Link Belt Co | Ferrous alloy and process of prodcing ferrous alloy |
| US2185894A (en) * | 1937-01-25 | 1940-01-02 | Hultgren Axel Gustaf Emanuel | Method of producing malleable iron |
| US2331886A (en) * | 1938-09-10 | 1943-10-19 | Gen Motors Corp | Alloy malleable iron |
| US2501059A (en) * | 1946-09-20 | 1950-03-21 | Kluijtmans Christian | Manufacture of black-heart malleable cast iron |
| US2651570A (en) * | 1949-11-19 | 1953-09-08 | Wisconsin Alumni Res Found | Manufacture of malleablized white cast iron |
-
0
- US US2899346D patent/US2899346A/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2077116A (en) * | 1933-04-07 | 1937-04-13 | Link Belt Co | Ferrous alloy and process of prodcing ferrous alloy |
| US2185894A (en) * | 1937-01-25 | 1940-01-02 | Hultgren Axel Gustaf Emanuel | Method of producing malleable iron |
| US2331886A (en) * | 1938-09-10 | 1943-10-19 | Gen Motors Corp | Alloy malleable iron |
| US2501059A (en) * | 1946-09-20 | 1950-03-21 | Kluijtmans Christian | Manufacture of black-heart malleable cast iron |
| US2651570A (en) * | 1949-11-19 | 1953-09-08 | Wisconsin Alumni Res Found | Manufacture of malleablized white cast iron |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3005736A (en) * | 1958-02-06 | 1961-10-24 | Renault | High-toughness cast-iron for relatively thick castings, and method of producing same |
| US4299622A (en) * | 1978-11-06 | 1981-11-10 | Sony Corporation | Magnetic alloy |
| US4911763A (en) * | 1988-07-15 | 1990-03-27 | Norcast Corporation | Process for producing a low alloy white cast iron |
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