CN1539026A - Carburized and quenched member and method for production thereof - Google Patents
Carburized and quenched member and method for production thereof Download PDFInfo
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- CN1539026A CN1539026A CNA028088751A CN02808875A CN1539026A CN 1539026 A CN1539026 A CN 1539026A CN A028088751 A CNA028088751 A CN A028088751A CN 02808875 A CN02808875 A CN 02808875A CN 1539026 A CN1539026 A CN 1539026A
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/20—Carburising
- C23C8/22—Carburising of ferrous surfaces
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
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Abstract
A carburizing and hardening method enhances strength while sufficiently reducing hardening strain, without increasing the production cost, and a carburized and hardened member produced thereby. The raw material is an alloy steel which contains Fe as a main component, 0.10 to 0.50 wt. % C and 0.50 to 1.50 wt. % Si and having a hardenability J, based on an end quenching test, in a range of 35 to 50 (at 12.5 mm). After the raw material is formed into the desired shape, a carburized layer is formed by carburizing in an oxidation inhibiting atmosphere. After the carburizing, quenching is performed with cooling, uninterrupted by temperature rise, from a pearlite transformation point (A1 point) to a martensite transformation start point (Ms point), and with a severity of quenching H in a range of 0.01 to 0.08 (cm<SUP>-1</SUP>).
Description
Technical field
The present invention relates to the carburizing and quenching parts and the manufacture method thereof of a kind of fatigue strength and dimensional precision excellence.
Background technology
For example in the transmission of power of automatic transmission with in the gear of parts etc., for improving surface hardness and toughness simultaneously, the carburizing and quenching parts of having implemented carburizing and quenching that adopt more.
Existing carburizing and quenching parts, generally adopt case-hardening steel (JIS:SCM420H, SCR420H, SNCM220) etc. to be configured as desirable shape after, place it in and carry out gas cementation in the carburizing atmosphere, quenching in wet goods then is made.
Yet,, require further can reduce cost and improve performance to above-mentioned carburizing and quenching parts.
Owing to reduce cost and improve performance is opposed, in the carburizing and quenching parts of the common carburization quenching method made that passes through the above-mentioned existing case-hardening steel of employing, need solve existing variety of issue one by one.
When one of problem that the carburizing and quenching parts are had is intensity after further improving carburizing and quenching, further suppress quenching strain, improve dimensional precision.
But, well-known, in the time of improving hardening capacity, usually, be associated with the increase quenching strain.Bring up to carburizing and quenching intensity before, might reduce processibility, increase tooling cost.
At the invention of relevant existing issue, its purpose is to provide a kind of carburizing and quenching parts and manufacture method thereof that can realize high strength under the situation that fully suppresses quenching strain just in the present invention.
Summary of the invention
The 1st aspect of the present invention, it is a kind of carburizing and quenching member manufacturing method, it is characterized in that adopting as steel billet (material) at the steel alloy of 35～50 (at12.5mm) with Si's and the end hardening test the hardening capacity J that contains Fe, contains the C of 0.10～0.50 weight % and 0.50～1.50 weight % simultaneously as principal constituent, after this steel billet being configured as the parts of desired shape, in preventing oxidizing atmosphere, form cementation zone by carburizing treatment
After carburizing treatment, from pearlitic transformation point (A1 point) under dull refrigerative condition the martensitic transformation starting point (Ms point), and be 0.01～0.08 (cm at quenching severity of quench H
-1) condition under carry out quench treatment.
At this, above-mentioned hardening capacity J according to the end hardening test is the value that the terminal hardening capacity (being commonly referred to as Jominy end hardening test method(s)) by the JIS:G0561 defined obtains.In addition, (at12.5mm) be meant in the bar-shaped test film of Jominy end hardening test usefulness, from the value of its water-cooled side end face apart from the locational hardening capacity J of 12.5mm.
In addition, above-mentioned quenching chilling value H be expression by Grossmann built justice and by the index of the intensity of extensively universal quenching, when the thermal conductivity of the steel of treated material is γ (kcal/mh a ℃), the surface heat transfer coefficient of above-mentioned steel is α (kcal/mh in quenching atmosphere
2℃) time, by H=0.5 * (α/γ) definition.
Then, in the present invention, the particular alloy steel that C content and Si content and hardening capacity are in the above-mentioned characteristic range adopts as steel billet, after in preventing oxidizing atmosphere, forming cementation zone, satisfy at the same time under both situations of condition of above-mentioned dull refrigerative condition and above-mentioned specific quenching severity of quench H and quench by carburizing treatment.That is, when definitely possessing all these material behaviors and creating conditions, the carburizing and quenching parts that can obtain fully to suppress quenching strain and realize high strength.
If further this point is described,, can guarantee the appropriate toughness and the intensity of non-carburizing portion (inside) behind the carburizing and quenching by allowing the above-mentioned C content be 0.10～0.50 weight %.On the other hand, when C content during less than 0.1 weight %, not too can obtain above-mentioned effect, in addition, when surpassing 0.50 weight %, hardness is too high before quenching, and might increase tooling cost and reduce toughness.In addition,, increase transformation stress, because big quenching strain becomes the major cause that reduces the parts precision because the tissue inter-variable of the non-carburizing portion inside behind the carburizing and quenching leads rising.
In addition, in the present invention, actively contain Si in its composition, in addition, its content is 0.50～1.50 weight %.Then, above-mentioned carburizing treatment is carried out in preventing oxidizing atmosphere.Like this, under the situation of the grain boundary oxidation that when suppressing carburizing treatment, is easy to generate, can improve face fatigue strength, improve hardening capacity, improve annealing softening opposing etc.At this,, particularly, there is the problem that reduces the effect of the anti-oxidation of crystal boundary in the carburizing treatment if the content of above-mentioned Si during less than 0.50 weight %, will reduce above-mentioned raising effect.On the other hand, if when surpassing 1.50 weight %, above-mentioned raising effect is saturated, the difficulty that becomes of the even austenitizing before quenching simultaneously.In addition, for the reduction of the plastic working, machinability or the plasticity that prevent material, preferably the content with Si is suppressed to below the 0.70 weight %.Therefore, the content of Si is more preferably more than 0.50 weight %, in the scope below the 0.70 weight %.
In addition, the above-mentioned hardening capacity J of above-mentioned steel billet is limited to 35～50 (at12.5mm).Like this, even the scope of above-mentioned quenching severity of quench H is limited to above-mentioned scope, can obtain excellent quenching effect.On the other hand, if above-mentioned hardening capacity J less than 35 o'clock, in the quenching technology after carburizing treatment, can not give sufficient quenching effect to above-mentioned cementation zone and non-carburizing portion (inside), can not realize desirable high strength.For this reason, more preferably above-mentioned hardening capacity J is more than 38.In addition,, particularly,, increase transformation stress, have the problem that is easy to generate quenching strain by allowing the tissue inter-variable of inside of non-carburizing portion lead rising if above-mentioned hardening capacity J surpasses at 50 o'clock.In addition, because this hardening capacity J is high more, the hardness before the carburizing and quenching is high more, reduces processibilities such as the preceding plastic working of carburizing treatment, machinability.For this reason, in order to prevent the reduction of these processibilities, preferred above-mentioned hardening capacity J is below 45.
In addition, above-mentioned quenching severity of quench H is limited to 0.01～0.08 (cm
-1).Then,, can when quenching, suppress quenching strain, guarantee the excellent size precision by using as steel billet with above-mentioned alloy with above-mentioned particular carbon amount and quenching performance.On the other hand, if above-mentioned quenching severity of quench H less than 0.01 (cm
-1) time and above-mentioned hardening capacity J same less than 35 o'clock situation, in the quenching technology after carburizing treatment, can not give sufficient quenching effect to above-mentioned cementation zone and non-carburizing portion (inside), can not realize desirable high strength.In addition, if quenching severity of quench H surpasses 0.08 (cm
-1) time and above-mentioned hardening capacity J to surpass 50 o'clock situation same, particularly,, increase transformation stress because the tissue inter-variable of the inside of non-carburizing portion leads rising, have the problem that is easy to generate quenching strain.
In addition, above-mentioned quench treatment not only in the scope of above-mentioned quenching severity of quench H, and must carried out under dull refrigerative condition the Ms point from the A1 point as mentioned above.In this so-called dull cooling, be meant in the cooling way no longer to be heated that promptly, the material temperature in the cooling can not rise again.Therefore when satisfying above-mentioned dull refrigerative condition, containing material temperature continues to descend, also allow temperature keep certain and will never rise even perhaps occur the descend state stop of temperature on the way, and then situation about descending, allow that certainly speed of cooling changes.
Then, by such dullness is cooled off as necessary condition, can suppress separating out of carbide.
In addition, under above-mentioned dull refrigerative condition, can select not with above-mentioned carburizing portion in carry out the refrigerative condition under the situation about intersecting of the nose zone of the S curve shown in the so-called constant temperature transformation curve.Like this, can guarantee sufficient martensitic transformation.
Then, in the present invention, as mentioned above, by possess above-mentioned C content, Si content, hardening capacity J, prevent in the oxidizing atmosphere carburizing treatment, satisfy both all conditions such as quench treatment of condition of above-mentioned dull refrigerative condition and above-mentioned specific quenching severity of quench H simultaneously, can under the situation that fully suppresses quenching strain, obtain to realize the carburizing and quenching parts of high strength, as long as lack in the above-mentioned important document, just may not reach desirable purpose.This is found through test of many times for the first time by this case applicant.
The 2nd aspect of the present invention is the carburizing and quenching parts that adopt above-mentioned manufacture method to make, and the surface hardness that it is characterized in that above-mentioned cementation zone is 700～900Hv, and the inside hardness of the non-carburizing portion of above-mentioned cementation zone inboard is 250～450Hv.
These carburizing and quenching parts adopt above-mentioned excellent manufacture method, and are adjusted to the divisional processing condition, and the inside hardness with the surface hardness of cementation zone and non-carburizing portion is limited to above-mentioned characteristic range as described above.Like this, for will act on the parts additional load produced to the imposed stress of parts and since concavo-convex, the hole of component shape etc. produced after near the concentrated stress the parts surface is synthetic, be attached to stress distribution on the parts, can guarantee static strength (tensile strength, flexural strength, transverse strength etc.) and dynamic strength (face fatigue strength, bending fatigue strength, distortion fatigue strength etc.) from the surface up to inner (heart portion).
If the surface strength of above-mentioned cementation zone is during less than 700Hv, near the stress concentration the parts surface, existence can not be guaranteed the temperature of its intensity.And may appear at the insufficient problem of the most lip-deep wear resistant.On the other hand,, on the top layer, generate carbide such as carbon body, insufficient strength on the contrary, the problem that particularly exists toughness to reduce if when surface hardness surpasses 900Hv.
In addition, if during less than 250Hv, particularly there is the insufficient problem of static strength in the inside hardness of above-mentioned non-carburizing portion.On the other hand,, consider,, produces big transformation stress, form big quenching strain thus, become the major cause of parts precision reduction if when guaranteeing that 450Hv carries out quench treatment according to the transformation ratio of tissue if when inner hardness surpasses 450Hv.
Description of drawings
Fig. 1 represents the explanatory view of rotoflector fatigue experiment sheet.
Fig. 2 (a) expression par orthographic plan of gear.
Fig. 2 (b) expression par sectional view of gear.
Specific embodiments
In the carburizing and quenching member manufacturing method aspect the of the present invention the 1st, above-mentioned carburizing treatment is preferably carried out in the reduced atmosphere of 1～30hPa that reduces pressure.Like this, can obtain the atmosphere of above-mentioned anti-oxidation, the grain boundary oxidation in the time of can fully preventing carburizing easily by reducing pressure.At this, when the pressure relief value of above-mentioned reduced atmosphere during, oxidation is suppressed to occur superfluous less than 1hPa, and the device that is used to pressurize also becomes high reliever, the problem that exists cost to increase.On the other hand, if when surpassing 30hPa, the effect of inhibited oxidation reduces, and exists in the problem that can produce coal in the cementing furnace.
In addition, above-mentioned carburizing treatment is preferably carried out under the atmosphere that with the rare gas element is principal constituent.At this moment, also can form the atmosphere of above-mentioned anti-oxidation easily.As above-mentioned non-rare gas element, nitrogen, argon gas etc. are for example arranged.
In addition, preferably arrive 0.6～1.5 weight % and carry out above-mentioned carburizing treatment like that according to the surface carbon amount of above-mentioned cementation zone.The surface carbon concentration of cementation zone influences the surface hardness of carburizing and quenching material, when the surface carbon concentration of cementation zone during less than 0.6 weight %, there is the insufficient problem of surface hardness, on the other hand, if surpass 1.5 weight %, the amount of separating out of carbide increases, and the through hardening performance of substrate significantly descends, and has the insufficient problem of surface hardness.
In addition, from the grain boundary oxidation that the surface produced of above-mentioned steel billet preferably below 3 μ m.That is, the one-tenth of steel billet is grouped into, and preferably preventing oxidizing atmosphere, Heating temperature, heat-up time etc. when adjusting above-mentioned carburizing is suppressed at above-mentioned grain boundary oxidation below surperficial 3 μ m.
Can reduce grain-boundary strength if generate grain boundary oxide (portion), generally the intensity than carburizing and quenching layer (portion) is low, if grain boundary oxidation surpasses 3 μ m, when producing in the depths, because the undercapacity of parts and hardness reduction etc. might cause the reduction of wear hardness.In addition, when grain boundary oxidation generated, its peripheral alloying element also can enter into grain boundary oxide owing to the compound reaction of chemical.Like this, the element that improves the through hardening performance in the carburizing and quenching layer of grain boundary oxide periphery enters into above-mentioned grain boundary oxide and is consumed, the zone that the additive exhaustion around the grain boundary oxide layer, occurs, the through hardening performance deficiency that carburizing and quenching layer itself might occur, thereby cause the hardness deficiency, the situation of undercapacity.
In addition, the surface compression residual stress of above-mentioned steel billet is preferably at 300～800MPa.That is, the one-tenth of steel billet is grouped into, and preferably preventing oxidizing atmosphere, Heating temperature, heat-up time etc. when adjusting above-mentioned carburizing allows above-mentioned surface compression residual stress more than 300MPa.Like this, the pulling force imposed stress of near surface, because near the compressive residual stress the parts surface, can mitigate effects stress, particularly can improve dynamic strength (face fatigue strength, bending fatigue strength, distortion fatigue strength).On the other hand, if when above-mentioned surface compression residual stress surpasses 800Mpa, martensite volume increases, and the speed of cooling in the time of must increasing quench treatment will go beyond the limit.For this reason, exist to produce big quenching strain, can not guarantee the problem of the dimensional precision of parts.
Above-mentioned surface compression residual stress can be by generating martensite to the cementation zone quench treatment, produced the stress under compression field by the volumetric expansion of following phase transformation and obtain.But, when martensitic growing amount more after a little while, that is, and retained austenite more for a long time, perhaps troostitic structures can not form enough compressive residual stress fields more for a long time.Therefore, reduce retained austenite (specifically below 25%) and reduce troostitic structures (specifically below 10%), have advantageous effect according to the viewpoint that improves such compressive residual stress effect.In addition, the absorption of the volumetric expansion during martensitic transformation more after a little while, can not relax pressure to allowing retained austenite on every side or troostitic structures viscous deformation at martensite volume, and increasing the surface compression residual stress has great effect.But, increase martensite volume above-mentioned and reduce retained austenite or troostitic structures if resemble, because the transposition density that viscous deformation imports increases, having retrained the distortion of sliding, can increase the surface compression residual stress rapidly.
In addition, processing such as the top layer of implementing shot peening (shot peening) processing after quenching is arranged to increase the method for compressive residual stress.For the latter, handle by shot peening, if allow behind the retained austenite formation of martensite, be favourable for improving the compression residual pressure.
In addition, above-mentioned quench treatment is preferably between the temperature to 300 of austenite region ℃, quench under the dull refrigerative condition in the scope of above-mentioned quenching severity of quench H.Like this, can obtain sufficient quenching effect.On the other hand, from the cooling between the temperature to 300 of austenite region ℃, above-mentioned quenching severity of quench H is less than 0.01 (cm
-1) time, become under hardening, can not guarantee desirable quenching structure, characteristic, cause the strength of parts deficiency.In addition, from the cooling between the temperature to 300 of austenite region ℃, if above-mentioned quenching severity of quench H surpasses 0.08 (cm
-1) time, the chilling surplus, augmenting tissue transformation stress and thermal stresses might increase quenching strain, reduce the parts precision.
In addition, above-mentioned quench treatment preferably utilizes gas cooling to quench.At this moment, than being easier to guarantee above-mentioned quenching severity of quench H.
In addition, the above-mentioned gas cooling is preferably carried out in rare gas element.Like this, the safety performance in the time of can guaranteeing to quench.
In addition, above-mentioned rare gas element nitrogen preferably.Nitrogen according to the property obtained, cost, viewpoint such as the property handled easily easily when producing in batches, preferably is used.
Then, in the carburizing and quenching parts aspect the of the present invention the 2nd, the retained austenite area occupation ratio of above-mentioned cementation zone is preferably below 25%.If the retained austenite area occupation ratio was above 25% o'clock, complete processing after carburizing quenching process or follow imposed stress, the temperature variation of parts in using, allow retained austenite take place to martensitic tissue inter-variable, transformation stress generation strain by at this moment might reduce the parts precision.In addition, the retained austenite area occupation ratio is more preferably below 20%.In addition, in order to have reduced the retained austenite area occupation ratio, for example can be by the shot peening processing etc., allow retained austenite force formation of martensite, to reduce area occupation ratio.
In addition, the area occupation ratio of the troostitic structures on above-mentioned cementation zone top layer is preferably below 10%.Above-mentioned troostite is the slack quenching tissue that generates in the cementation zone behind carburizing and quenching, because hardness is little, when the area occupation ratio of tissue surpasses 10%, because low intensive troostite might reduce the intensity of parts.
In addition, above-mentioned carburizing and quenching parts, preferably its interior tissue is a bainite.Say that more specifically the area occupation ratio of preferred bainite is more than 50% in section structure.Bainite is different with martensite, and the iron atom that becomes lattice carries out phase transformation under the situation of part diffusion.Therefore since with should diminishing that martensitic phase is relatively followed phase transformation and produced, and further the pearlitic hardness that is generated when reducing speed of cooling is big, can appropriateness improves the intensity of inboard non-carburizing portion.In order to be that main body constitutes the internal layer side with the bainite, by above-mentioned cooling severity of quench is set in 0.01～0.08 (cm
-1) scope, according to obtaining to form selected like that based on the tissue of bainite.Like this, can obtain to have intensity and flexible parts.
In addition, above-mentioned carburizing and quenching parts, preferably carburized gears.Gear is the parts of the various stringent conditions of requirement, and the excellent specific property of utilizing above-mentioned manufacture method to obtain is very effective to gear.
Embodiment
For the carburizing and quenching parts of relevant embodiments of the invention, further adopt concrete example to be elaborated.
(embodiment 1)
As embodiment 1, to for confirming that the experimental result that effect of the present invention is carried out describes.
At first, after the steel of chemical constitution shown in the table 1 (steel 11～14) adopted arc melting, forming diameter by hot rolling was that 150mm and diameter are the pole of 32mm, kept the cold normalizing of laggard line space in 1 hour at 925 ℃.
Steel 11, steel 12 are to have the steel grade that one-tenth newly developed is grouped in the present embodiment, and steel 13 and steel 14 are equivalent to the case-hardening steel SCM420 of JIS and the steel grade of SNCM815 respectively.
At first,, carry out the terminal hardening capacity experiment of Jominy, obtain hardening capacity according to JIS:G0561 for all steel grades.
Its result is as shown in table 1.This characteristic is the characteristic with the irrelevant steel billet of manufacture method described later.
(table 1)
| Steel grade | Composition element (wt%) | Hardening capacity J | |||||||||||
| C | ?Si | ?Mn | ?S | ?Ni | Cr | Mo | ?B | ?Ti | ?Nb | ?Al | ?N | ||
| ??11 ??12 ??13 ??14 | 0.16 0.18 0.20 0.15 | ?0.56 ?0.75 ?0.21 ?0.25 | ?0.38 ?0.35 ?0.78 ?0.47 | ?0.012 ?0.009 ?0.011 ?0.009 | ?0.96 ?0.71 ?0.02 ?4.34 | 1.47 2.22 1.01 0.83 | 0.01 0.01 0.17 0.27 | ?0.0022 ?0.0018 ?- ?- | ?0.044 ?0.035 ?- ?- | ?0.05 ?0.03 ?- ?- | ?0.013 ?0.019 ?0.027 ?0.040 | ?0.006 ?0.005 ?0.015 ?0.018 | ????38 ????42 ????25 ????37 |
Show that by table 1 steel 11, steel 12 are to can be used as the steel alloy that steel billet of the present invention is suitable for according to the viewpoint of material and hardening capacity J.On the other hand, steel 13, its hardening capacity J and Si content exceed outside the scope of the invention, and steel 14, its Si content exceeds outside the scope of the invention.
Then, adopt above-mentioned steel 11～14, be processed into the pole test film (not drawing among the figure) of diameter 25mm, length 50mm, and be processed into the rotary bending fatigue test sheet 1 of shape shown in Figure 1.
In addition,, as shown in Figure 2, be made into pitch radius 54mm, the number of teeth 27, the test of modulus 4, facewidth 9mm, axis hole radius 35mm (pole radius 10.5mm φ of equal value) gear 4 by mechanical workout from the normalizing material of diameter 150mm.
To carry out low-pressure carburization (vacuum carburization) and gas quenching according to the condition of [method for making 1] shown in the table 2 by each test film and the gear of above-mentioned steel 11,12 and steel 14 making then.
In addition, each test film to being made by steel 13 carries out gas cementation and oil quenching according to the condition of [method for making 2] shown in the table 3.
At this, above-mentioned [method for making 1], as shown in table 1, quenching severity of quench H is 0.05 (cm after the carburizing treatment
-1), possessed the underlying condition of manufacture method of the present invention.
In addition, above-mentioned [method for making 2], as shown in table 4, quenching severity of quench H is 0.15 (cm after the carburizing treatment
-1), do not possess the underlying condition of manufacture method of the present invention.
Then, above such each test film of making is carried out following test.
At first, for the pole test film of diameter 25mm, adopt Vickers hardness tester to measure the Hardness Distribution (inner hardness) of cross section.In addition, the surface hardness of carburizing and quenching material (surface hardness) is measured on the position from the surface to 0.02mm.Further, with the area occupation ratio of the troostite of its equivalent locations,, electron scanning micrograph measures by being carried out image analysis.
In addition, the grain boundary oxidation layer adopts opticmicroscope, measures from surface metal and is organized into the maximum zone of oxidation degree of depth.
In addition, surface carbon concentration adopts X-ray microanalyzer measuring on the position of surperficial 50 μ m.
In addition, the retained austenite area occupation ratio adopts the Co-Ka line that parts surface is measured in the X-ray diffraction device.
In addition, remained on surface stress adopts the X ray stress detector to adopt Fe-K α line to utilize half price width mid-point method to measure.
These measuring results are as shown in table 4.
(table 2) method for making 1
| Technology | Temperature | Time | Atmosphere gas | Pressure | Quenching severity of quench H |
| Carburizing | 930℃ | 2 hours | Acetylene | ??20mbar | - |
| Diffusion | 930℃ | 1 hour | Acetylene | ??20mbar | - |
| Soaking | 850℃ | 0.5 hour | Acetylene | ??20mbar | - |
| Quench | - | ?- | Nitrogen | ??8bar | 0.05cm -1 |
| Annealing | 150℃ | 2 hours | Atmosphere | Normal atmosphere | - |
(table 3) method for making 2
| Technology | Temperature | Time | Atmosphere gas | Pressure | Quenching severity of quench H |
| Carburizing | ??930℃ | 3 hours | React the CO that forms, H by becoming of butane and air 2，N 2Deng mixed gas | Normal atmosphere | - |
| Diffusion | ??930℃ | 1 hour | React the CO that forms, H by becoming of butane and air 2，N 2Deng mixed gas | Normal atmosphere | - |
| Soaking | ??850℃ | 0.5 hour | React the CO that forms, H by becoming of butane and air 2，N 2Deng mixed gas | Normal atmosphere | - |
| Quench | ??120℃ | - | Oil | Normal atmosphere | 0.05cm -1 |
| Annealing | ??150℃ | 2 hours | Atmosphere | Normal atmosphere | - |
As shown in table 4, the hardness of the central part of the carburizing and quenching material " steel 11,12+ method for making 1 " (combination of following steel grade and method for making is designated as " steel grade+method for making ") that obtains after 1 pair of steel 11 of employing method for making, steel 12 are handled is all more than 250Hv.Organizing of top layer and central part all is martensite, do not have remarkable slack quenching tissue.
(table 4)
| Steel grade | Carburizing quenching process | Grain boundary oxidation layer (μ m) | Top layer carbon concentration (%) | Troostite area occupation ratio (%) | Surface hardness (Hv) | Retained austenite area occupation ratio (%) | Remained on surface stress (MPa) | Inner hardness (Hv) | ????10 7Limit of fatigue | |
| Flexural fatigue (MPa) | Face fatigue (Mpa) | |||||||||
| 11 | (method for making 1) vacuum carburization+gas cooling | ?1.2 | ?0.68 | ?7.0 | 779 | ????14.2 | ??-314 | ?393 | ??1098 | ?3750 |
| 12 | ?2.2 | ?1.24 | ?2.5 | 839 | ????19.1 | ??-330 | ?423 | ??1080 | ?4260 | |
| ? 13 ? ? 14 | (method for making 2) gas cementation-oil cooling (method for making 1) vacuum carburization+gas cooling | ? ?10.7 ? ? ?5.8 | ? ?0.78 ? ? ?0.66 | ? ?37.7 ? ? ?9.1 | ? 631 ? ? 729 | ? ????7.1 ? ? ????22.5 | ? ??-69 ? ? ??-125 | ? ?267 ? ? ?384 | ? ??900 ? ? ??1053 | ? ?3000 ? ? ?3090 |
To this, the surface hardness and the central part hardness of " steel 13+ method for making 2 " are compared all low with any of above-mentioned " steel 11,12+ method for making 1 ".
In addition, the surface hardness and the central part hardness of " steel 14+ method for making 1 ", though about equally, the retained austenite area occupation ratio is big and remained on surface is little with above-mentioned " steel 11,12+ method for making 1 ".Cause that thus fatigue strength is poor.
Then, little wild formula rotating bending fatigue machine is adopted in rotary bending fatigue test, and obtaining to repeat 1,000 ten thousand times is the fatigue strength of benchmark.Its result represents in table 4 as flexural fatigue, face fatigue.
From table 4, show, in " steel 11,12+ method for making 1 ", obtain to have than " steel 13+ method for making 1 " and " steel 14+ method for making 1 " much bigger characteristic for rotoflector fatigue strength.
Then, for gear, par magnetic force precision and dimensional precision in such a way.
When the par accuracy of gear, adopt special-purpose precision gear precision determination instrument, respectively the left and right sides flank of tooth is measured the magnitude of error of all directions pressure of gear and the magnitude of error of torsional angle direction.In addition, full week is measured groove height, subtracts the deflection calculation of the difference of minimum value as teeth groove with maximum value.
When the par dimensional precision, in intermeshing 2 teeth groove of gear, put into spheroid, its peripheral dimension adopts special-purpose O.B.D determinator to measure.O.B.D measures, and as shown in Figure 2, circumferential direction is that (X, Y), facewidth direction is divided 3 places, upper, middle and lower (A, B, C) to vertical 2 directions.Then,, obtain the absolute value of the difference of the O.B.D on vertical 2 directions,, obtain the poor of top O.B.D on facewidth direction and bottom O.B.D as the O.B.D taper as the O.B.D ellipse.Its result is as shown in table 5.
(table 5)
| Steel grade | Carburizing quenching process | The accuracy of gear (%) | Dimensional precision (%) | |||||
| The flank of tooth | Departing from of each characteristic | The deflection of teeth groove | O.B.D departs from | The O.B.D ellipse | The O.B.D taper | |||
| Pressure angle error | The torsional angle error | |||||||
| ??11 | Method for making 1 | Right | ??45 | ????51 | ??68 | ??70 | ?82 | ??35 |
| A left side | ??48 | ????49 | ||||||
| ??12 | Method for making 1 | Right | ??62 | ????65 | ??73 | ??78 | ?81 | ??40 |
| A left side | ??58 | ????60 | ||||||
| ??13 | Method for making 2 | Right | ??100 | ????100 | ??100 | ??100 | ?100 | ??100 |
| A left side | ??100 | ????100 | ||||||
| ??14 | Method for making 1 | Right | ??47 | ????48 | ??70 | ??65 | ?80 | ??30 |
| A left side | ??50 | ????55 | ||||||
Shown that by table 5 accuracy of gear, dimensional precision are, " steel 11,12+ method for making 1 " has more excellent precision than other.
According to above result, adopt as steel billet for the particular alloy steel that is in the above-mentioned specified range with C content and Si content and hardening capacity J, after in preventing oxidizing atmosphere, forming cementation zone by carburizing treatment, under the situation of " steel 11,12+ method for making 1 " after quenching under the condition of above-mentioned specific quenching severity of quench H, quenching strain can be fully suppressed, and high strength can be realized.
Particularly for steel alloy,,, set for and contain C:0.12～0.22 quality % as principal constituent with Fe as minor component, Si:0.5～1.5 quality %, Mn:0.25～0.45 quality %, Ni:0.5～1.5 quality %, Cr:1.3～2.3 quality %, B:0.001～0.003 quality %, Ti:0.02～0.06 quality %, Nb:0.02～0.12 quality %, Al:0.005～0.05 quality % gets final product.
More specifically say, as above-mentioned steel alloy,
Get final product forming adjustment below 95 by the composition parameter N of N ≡ 106 * C (quality %)+10.8 * Si (quality %)+19.9 * Mn (quality %)+16.7 * Ni (quality %)+8.55 * Cr (quality %)+45.5 * Mo (quality %)+28 expression.
At this, the N of above-mentioned steel grade 11,12 is respectively 87.6,93.4, the steel grade 13,14 outside composition range of the present invention, and its N is bigger than 95.If N surpasses 95, the hardness of the state of rolling of steel and the hardness of as-normalized condition significantly rise, machinability that can not obtain and cold-workability.Therefore, when paying attention to manufacturability, need this composition parameter is controlled at below 95.
Become the interior steel alloy of composition range of the invention described above, speed of cooling does not generate bainite at least when the scope below 0.1 ℃/second, and speed of cooling does not generate ferrite at least when the scope more than 12 ℃/second.In above-mentioned speed of cooling scope, the continuous cooling transformation graphic representation of steel (Continuous Cooling Transformation diagram:CCT graphic representation) can be determined by various speed of cooling are measured.
In the present invention, even adopt gas cooling also can fully quench, allow the composition of steel be configured to also can not generate ferrite in the zone of (below become upper limit speed of cooling) more than 12 ℃/second at least in speed of cooling to cementation zone in order to reach.If speed of cooling is increased to generation ferrite in back more than 12 ℃/second, adopt gas cooling just can not in cementation zone, fully form martensite, can cause the hardness deficiency.
But, when hardening capacity is excessively good, detrimental action is arranged on the contrary, if in the internal layer portion of the influence that is not subjected to carburizing the also superfluous martensite that generates, the martensite growing amount of parts integral body increases, and can cause that dimensional precision reduces.For this reason, when gas quenching, according to can generate enough martensite in cementation zone, not coming selected the composition like that and do not form over-drastic martensite in internal layer portion, is very important.Specifically, do not generate bainite during at least in the scope below 0.1 ℃/second when speed of cooling.If when the speed of cooling below 0.1 ℃/second, also generate bainite, the internal layer portion of the influence that is not subjected to carburizing is quenched, the result can increase strain.
In addition,, the generation of bainite can be fully suppressed, the many tissues that is rich in processibility of ferrite+perlite can be obtained in the annealing speed of cooling scope of reality if under less than 0.1 ℃/second speed of cooling, do not generate bainite.Therefore, as-annealed condition promptly in the scope of cooling off or be equivalent to air cooling from austenitic speed of cooling to placement, can obtain to improve the enough low steel billet hardness of processing characteristics, carries out the preceding processing of carburizing and quenching easily.
Further, by allowing speed of cooling, wish to obtain to form selected, particularly, wish to become the bainite main body when cooling off with 3 ℃/s based on the tissue of bainite according to internal layer portion at 0.1～10 ℃/s.
(embodiment 2)
In this example, the piece steel is made in the steel of chemical ingredients shown in the his-and-hers watches 6 (steel 21～24 and steel 31～38) melting, and piecemeal is rolled then, manufactures the pole of diameter 70mm.
Then, the pole of 70mm φ is extended into 120mm φ by heat forged, after 925 ℃ of normalizing treatment, be made into each test film and the gear (referring to Fig. 1, Fig. 2) same with embodiment 1.
Then, each test film and gear are handled according to 3 kinds of manufacture method (method for making 3～5).
The characteristics of " method for making 3 " are to adopt gas cementation and oil quenching, in carburizing gas atmosphere according to → 130 ℃ of oil quenching → 180 of heating in 930 ℃ * 5 hours diffusion in → 850 ℃ * 1 hour ℃ * the annealed condition was carried out carburizing and quenching in 1 hour, annealing.At this moment quenching severity of quench H is 0.15 (cm
-1).
The characteristics of " method for making 4 " are to adopt vacuum carburization and gas cooling, carry out carburizing and quenching, annealing according to → 180 ℃ * 1 hour annealed condition of heating in 930 ℃ * 5 hours diffusion → nitrogen cooling in → 850 ℃ * 1 hour in vacuum carburization.At this moment quenching severity of quench H is 0.05 (cm
-1).
" method for making 5 " is that the cooling of the nitrogen in the above-mentioned method for making 4 is altered to 130 ℃ of oil quenching, and quenching severity of quench H at this moment is 0.15 (cm
-1).
Then, to utilizing each test film and the gear after above-mentioned method for making is handled, carry out mensuration and the test identical with embodiment 1.
Its result is shown in table 7, table 8.
Shown in table 7, table 8, for steel grade 31～38, bending fatigue strength or face fatigue strength are low, in addition, adopt oil cooled parts because quenching strain, precision depart from increase, problem is many in practicality.
For steel grade 31～34, the grain boundary oxidation during owing to gas cementation generates and can form the slack quenching tissue, causes that thus surface hardness is low, has reduced each intensity.In addition, when adopting oil cooling, it is rapider than adopting gas cooling to quench, and the cooling spot is big, because quenching strain can increase the departing from property of precision.
In addition, for steel grade 37,38, for the hardening capacity of steel, adopt oil cooled quenching too strong, inner hardness rises excessively.In addition, the relative mistake between the tissue inter-variable of the tissue inter-variable on surface and inside reduces, that is, the difference of surface hardness and inner hardness reduces, and its result can reduce the top layer compressive residual stress, reduces each intensity.In addition, when adopting oil cooling, it is rapider than adopting gas cooling to quench, and the cooling spot is big, because quenching strain can increase the departing from property of precision.
On the other hand, in steel grade 21～24, all demonstrate the surface hardness height, and inner hardness is suitable, and strain can be suppressed to lessly, can have high strength and low strain simultaneously.
Therefore, in this example, also be to adopt as steel billet for the particular alloy steel that is in the above-mentioned specified range with C content and Si content and hardening capacity J, after in preventing oxidizing atmosphere, forming cementation zone by carburizing treatment, situation after quenching under the condition of above-mentioned specific quenching severity of quench H, quenching strain can be fully suppressed, and high strength can be realized.
At this moment, for steel alloy, with Fe as principal constituent, as minor component, set for and contain C:0.1～0.5 quality %, Si:0.5～1.0 quality %, Mn:0.3～1.0 quality %, Cr:0.1～1.0 quality %, P:0.003～0.015 quality %, S:0.005～0.03 quality %, Al:0.01～0.06 quality %, N:0.005～0.03 quality % contains Mo:0.3～1.3 quality % simultaneously, and Ni:0.1～1.0 quality % get final product more than a kind.Further, as minor component, also can contain V:0.05～1.5 quality %, Nb:0.02～0.2 quality %, more than a kind of Ti:0.01～0.2 quality %, perhaps B:0.0005～0.005 quality %, Ti:0.005～0.1 quality %, perhaps B:0.0005～0.005 quality %, Yi:0.011～0.2 quality %.Be further used as other element, also can be according to quality %, contain and be selected from below the Ca:0.01%, below the Mg:0.01%, below the Zr:0.05%, containing at least more than a kind among the following group who is constituted of Te:0.1%.
(table 6)
| Steel grade | Composition element (wt%) | Hardening capacity J | ||||||||||
| C | Si | Mn | ?P | ?S | ?Cr | ?Al | ??Mo | Other ﹠ grain refined element | Trace element (ppm) | N(ppm) | ||
| ? ??21 ? ? ??22 ? ? ??23 ? ??24 | ? 0.15 ? ? 0.15 ? ? 0.15 ? 0.25 | ? 0.50 ? ? 0.50 ? ? 1.00 ? 0.50 | ? 0.50 ? ? 0.50 ? ? 0.86 ? 0.35 | ? ?0.008 ? ? ?0.003 ? ? ?0.010 ? ?0.015 | ? ?0.015 ? ? ?0.011 ? ? ?0.014 ? ?0.012 | ? ?0.12 ? ? ?0.50 ? ? ?0.12 ? ?0.90 | ? ?0.020 ? ? ?0.020 ? ? ?0.018 ? ?0.035 | ? ??1.00 ? ? ??0.95 ? ? ??1.00 ? ??0.91 | V：0.10，Nb：0.03， Ti：0.02 Ni：0.30，V：0.10， ? Nb：0.02，Ti：0.02 V：0.10，Nb：0.03， ? Ti：0.02 ? Nb：0.02 | Te：20,Zr：20， B：20 Ca：20，Zr：50 ? B：20 Te：15，Zr：10， ? B：15 ? Mg：30 | ? 142 ? ? 132 ? ? 135 ? 145 | ? ??38 ? ? ??44 ? ? ??38 ? ??31 |
| ??31 | 0.21 | 0.25 | 0.70 | ?0.015 | ?0.015 | ?1.06 | ?0.030 | ??0.15 | - | - | 130 | ??28 |
| ??32 | 0.19 | 0.26 | 0.80 | ?0.019 | ?0.014 | ?1.13 | ?0.035 | ??0.02 | - | - | 138 | ??26 |
| ??33 | 0.15 | 0.50 | 0.50 | ?0.010 | ?0.015 | ?0.44 | ?0.035 | ??1.01 | V：0.10，Nb：0.03 | Ca：20 | 130 | ??28 |
| ??34 | 0.15 | 0.50 | 0.50 | ?0.008 | ?0.015 | ?0.12 | ?0.020 | ??1.00 | V：0.10，Nb：0.03， Ti：0.02 | Te：20，Zr：20， B：20 | 142 | ??38 |
| ??35 | 0.21 | 0.25 | 0.70 | ?0.015 | ?0.015 | ?1.06 | ?0.030 | ??0.15 | - | - | 130 | ??28 |
| ??36 | 0.19 | 0.26 | 0.80 | ?0.019 | ?0.014 | ?1.13 | ?0.035 | ??0.02 | - | - | 138 | ??26 |
| ??37 | 0.15 | 0.50 | 0.50 | ?0.010 | ?0.015 | ?0.44 | ?0.035 | ??1.01 | V：0.10，Nb：0.03 | Ca：20 | 130 | ??28 |
| ??38 | 0.15 | 0.50 | 0.50 | ?0.008 | ?0.015 | ?0.12 | ?0.020 | ??1.00 | V：0.10，Nb：0.03， Ti：0.02 | Te：20，Zr：20， B：20 | 142 | ??38 |
(table 7)
| Steel grade | Carburizing quenching process | Grain boundary oxidation layer (μ m) | Top layer carbon concentration (%) | Troostite area occupation ratio (%) | Surface hardness (Hv) | Retained austenite area occupation ratio (%) | Remained on surface stress (MPa) | Inner hardness (Hv) | 107 limit of fatigue | |
| Flexural fatigue (MPa) | Face fatigue (Mpa) | |||||||||
| ????21 ????22 ????23 ????24 | (method for making 4) vacuum carburization+gas cooling | ????0 ????0 ????0 ????0 | ??0.67 ??0.61 ??0.68 ??0.62 | ????3 ????3 ????3 ????4 | ?845 ?847 ?844 ?840 | ????6 ????8 ????7 ???-9 | ??-392 ??-370 ??-390 ??-390 | ?280 ?315 ?275 ?300 | ??1200 ??1250 ??1200 ??1200 | ?3500 ?3500 ?3500 ?3600 |
| ????31 ????32 ????33 ????34 | (method for making 3) gas cementation+oil cooling | ????15 ????5 ????18 ????20 | ??0.61 ??0.66 ??0.61 ??0.62 | ????41 ????28 ????40 ????43 | ?680 ?670 ?780 ?770 | ????20 ????22 ????18 ????17 | ???50 ???40 ???80 ???90 | ?290 ?280 ?350 ?360 | ??800 ??750 ??900 ??900 | ?2800 ?2800 ?3100 ?3000 |
| ????35 ????36 | (method for making 4) vacuum carburization+gas cooling | ????0 ????0 | ??0.68 ??0.69 | ????2 ????3 | ?813 ?780 | ????12 ????13 | ??-360 ??-300 | ?230 ?220 | ??1000 ??1000 | ?3100 ?3200 |
| ????37 ????38 | (method for making 5) vacuum carburization+oil cooling | ????0 ????0 | ??0.66 ??0.64 | ????3 ????4 | ?780 ?850 | ????10 ????10 | ??-160 ??-100 | ?390 ?400 | ??1000 ??1000 | ?3000 ?3100 |
(table 8)
| Steel grade | Carburizing quenching process | The accuracy of gear (%) | Dimensional precision (%) | |||||
| The flank of tooth | Departing from of each characteristic | The deflection of teeth groove | O.B.D departs from | The O.B.D ellipse | The O.B.D taper | |||
| Pressure angle error | The torsional angle error | |||||||
| ??21 | (method for making 4) vacuum carburization+gas cooling | Right | ??48 | ??60 | ??65 | ??55 | ??80 | ??36 |
| A left side | ??52 | ??54 | ||||||
| ??22 | Right | ??47 | ??55 | ??70 | ??68 | ??85 | ??48 | |
| A left side | ??48 | ??59 | ||||||
| ??23 | Right | ??60 | ??67 | ??66 | ??70 | ??77 | ??32 | |
| A left side | ??52 | ??61 | ||||||
| ??24 | Right | ??51 | ??56 | ??64 | ??60 | ??79 | ??47 | |
| A left side | ??47 | ??52 | ||||||
| ??31 | (method for making 3) gas cementation+oil cooling | Right | ??103 | ??108 | ??105 | ??98 | ??100 | ??110 |
| A left side | ??112 | ??105 | ||||||
| ??32 | Right | ??99 | ??105 | ??100 | ??100 | ??110 | ??105 | |
| A left side | ??18 | ??98 | ||||||
| ??33 | Right | ??110 | ??105 | ??101 | ??108 | ??106 | ??99 | |
| A left side | ??105 | ??104 | ||||||
| ??34 | Right | ??102 | ??109 | ??106 | ??111 | ??111 | ??107 | |
| A left side | ??106 | ??110 | ||||||
| ??35 | (method for making 4) vacuum carburization+gas cooling | Right | ??60 | ??59 | ??70 | ??65 | ??77 | ??43 |
| A left side | ??51 | ??65 | ||||||
| ??36 | Right | ??59 | ??55 | ??78 | ??64 | ??85 | ??48 | |
| A left side | ??54 | ??59 | ||||||
| ??37 | (method for making 5) vacuum carburization+oil cooling | Right | ??99 | ??106 | ??105 | ??97 | ??110 | ??102 |
| A left side | ??108 | ??111 | ||||||
| ??38 | Right | ??100 | ??100 | ??100 | ??100 | ??100 | ??100 | |
| A left side | ??100 | ??100 | ||||||
Claims (15)
1. a carburizing and quenching member manufacturing method is characterized in that
Adopt as steel billet at the steel alloy of 35～50 (at12.5mm) with Si's and the end hardening test the hardening capacity J that contains Fe, contains the C of 0.10～0.50 weight % and 0.50～1.50 weight % simultaneously as principal constituent, after this steel billet being configured as the parts of desired shape, in preventing oxidizing atmosphere, form cementation zone by carburizing treatment
After carburizing treatment, from pearlitic transformation point (A1 point) under dull refrigerative condition the martensitic transformation starting point (Ms point), and be 0.01～0.08 (cm at quenching severity of quench H
-1) condition under carry out quench treatment.
2. carburizing and quenching member manufacturing method according to claim 1 is characterized in that described carburizing treatment, carries out under the reduced atmosphere of 1～30hPa that reduces pressure.
3. carburizing and quenching member manufacturing method according to claim 1 is characterized in that described carburizing treatment, carries out in the atmosphere that with the rare gas element is principal constituent.
4. carburizing and quenching member manufacturing method according to claim 1 is characterized in that making surface carbon amount to the 0.6～1.5 weight % of described cementation zone to carry out described carburizing treatment like that.
5. carburizing and quenching member manufacturing method according to claim 1, the grain boundary oxidation that it is characterized in that producing from the surface of described steel billet is below 3 μ m.
6. carburizing and quenching member manufacturing method according to claim 1, the surface compression residual stress that it is characterized in that described steel billet is 300～800MPa.
7. carburizing and quenching member manufacturing method according to claim 1 is characterized in that described quench treatment between the temperature to 300 of austenite region ℃, quenches in the scope of described quenching severity of quench H.
8. carburizing and quenching member manufacturing method according to claim 1 is characterized in that described quench treatment quenches by gas cooling.
9. carburizing and quenching member manufacturing method according to claim 8 is characterized in that described gas cooling carries out in rare gas element.
10. carburizing and quenching member manufacturing method according to claim 9 is characterized in that described rare gas element is a nitrogen.
11. carburizing and quenching parts are the carburizing and quenching parts that adopt the described manufacture method of claim 1 to make, the surface hardness that it is characterized in that described cementation zone is 700～900Hv, and the inside hardness of the non-carburizing portion of described cementation zone inboard is 250～450Hv.
12. carburizing and quenching parts according to claim 11, the retained austenite area occupation ratio that it is characterized in that described cementation zone is below 25%.
13. carburizing and quenching parts according to claim 11, the area occupation ratio of troostitic structures that it is characterized in that described cementation zone is below 10%.
14. carburizing and quenching parts according to claim 11 is characterized in that described interior tissue is a bainite.
15. the manufacture component of carburizing and quenching parts is characterized in that, in claim 11, described carburizing and quenching parts are carburized gears.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001392410 | 2001-12-25 | ||
| JP392410/2001 | 2001-12-25 |
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|---|---|
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|---|---|---|---|
| CNA028088751A Pending CN1539026A (en) | 2001-12-25 | 2002-12-25 | Carburized and quenched member and method for production thereof |
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|---|---|
| US (1) | US20050173026A1 (en) |
| EP (1) | EP1550736A4 (en) |
| JP (1) | JP4354277B2 (en) |
| KR (1) | KR20040088016A (en) |
| CN (1) | CN1539026A (en) |
| WO (1) | WO2003056054A1 (en) |
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| WO2004059029A1 (en) * | 2002-12-25 | 2004-07-15 | Aisin Aw Co., Ltd. | Carburized and quenched member and method for manufacture thereof |
| DE102005061946B4 (en) * | 2004-12-27 | 2013-03-21 | Nippon Steel Corp. | Case hardened steel having excellent tooth surface fatigue strength, gear using the same, and methods of making same |
| JPWO2006118242A1 (en) * | 2005-04-28 | 2008-12-18 | アイシン・エィ・ダブリュ株式会社 | Steel member and heat treatment method thereof |
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| JPH11310824A (en) * | 1998-04-30 | 1999-11-09 | Aisin Aw Co Ltd | Carburized and quenched steel member and its manufacture |
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- 2002-12-25 JP JP2003556568A patent/JP4354277B2/en not_active Expired - Fee Related
- 2002-12-25 EP EP02790874A patent/EP1550736A4/en not_active Withdrawn
- 2002-12-25 US US10/473,716 patent/US20050173026A1/en not_active Abandoned
- 2002-12-25 KR KR10-2004-7002801A patent/KR20040088016A/en not_active Application Discontinuation
- 2002-12-25 WO PCT/JP2002/013561 patent/WO2003056054A1/en not_active Application Discontinuation
- 2002-12-25 CN CNA028088751A patent/CN1539026A/en active Pending
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| CN105803161A (en) * | 2015-01-15 | 2016-07-27 | 丰田自动车株式会社 | Heat treatment method for steel material |
| CN108603261A (en) * | 2016-03-08 | 2018-09-28 | 爱信艾达株式会社 | The manufacturing method of steel part, geared parts and steel part |
| US10889870B2 (en) | 2016-03-08 | 2021-01-12 | Aisin Aw Co., Ltd. | Steel component, gear component, and producing method for steel component |
Also Published As
| Publication number | Publication date |
|---|---|
| US20050173026A1 (en) | 2005-08-11 |
| EP1550736A1 (en) | 2005-07-06 |
| KR20040088016A (en) | 2004-10-15 |
| EP1550736A4 (en) | 2005-07-06 |
| WO2003056054A1 (en) | 2003-07-10 |
| JP4354277B2 (en) | 2009-10-28 |
| JPWO2003056054A1 (en) | 2005-05-12 |
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