CN104630634B - The excellent carburizing steel of forging and its manufacture method - Google Patents

The excellent carburizing steel of forging and its manufacture method Download PDF

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CN104630634B
CN104630634B CN201510028676.6A CN201510028676A CN104630634B CN 104630634 B CN104630634 B CN 104630634B CN 201510028676 A CN201510028676 A CN 201510028676A CN 104630634 B CN104630634 B CN 104630634B
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steel
carburizing
spheroidizing
ferrite
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CN104630634A (en
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宫克行
一宫克行
三田尾真司
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JFE Engineering Corp
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NKK Corp
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    • 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
    • C21D1/06—Surface hardening
    • 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
    • C21D1/26—Methods of annealing
    • C21D1/32—Soft annealing, e.g. spheroidising
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/32—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for gear wheels, worm wheels, or the like
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/02—Making non-ferrous alloys by melting
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • 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
    • C23C8/02—Pretreatment of the material to be coated
    • 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
    • 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
    • C23C8/80—After-treatment
    • 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
    • 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
    • C21D2211/009—Pearlite

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  • Chemical & Material Sciences (AREA)
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  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Heat Treatment Of Steel (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)

Abstract

The present invention provides a kind of carburizing steel, contains in the scope for meeting following formula (1), (2) and (3)：In terms of quality %, C：0.1~0.35%, Si：0.01~0.22%, Mn：0.3~1.5%, Cr：1.35~3.0%, P：Less than 0.018%, S：Less than 0.02%, Al：0.015~0.05%, N：0.008~0.015% and O：Less than 0.0015%, remainder is the composition of Fe and inevitable impurity, also, the ferrite of structure of steel and total tissue point rate of pearlite are more than 85%, and ferritic average grain diameter is less than 25 μm.Wherein, [%M] is the content (quality %) of element M for 3.1 >={ ([%Si]/2)+[%Mn]+[%Cr] } >=2.2 (1) [%C] ([%Si]/2)+([%Mn]/5)+2,2.5 >=[%Al] of [%Cr] >=3.0 (2)/[%N] >=1.7 (3).

Description

The excellent carburizing steel of forging and its manufacture method
The application be Application No. 201180048735.6, the applying date be November 29, entitled " cold forging in 2011 The divisional application of the patent application of the excellent carburizing steel of property and its manufacture method ".
Technical field
The present invention relates to the excellent carburizing steel of the forging suitable for automobile, various industrial machines etc. and its manufacturer Method.
Background technology
In recent years, for the gear used in automobile etc., along with the light weight of the car body weight as caused by energy-saving Change, it is desirable to compact in size, the load for putting on gear is becoming big.In addition, along with the high output of engine, putting on tooth The load of wheel is also becoming big.The main surface pressing fatigue according to the destruction of the flexural fatigue of tooth root and the flank of tooth of the durability of gear is broken Go bad to determine.
In the past, gear was used in the Surface hardened layer that SCM420H, SCM822H etc. are defined as in JIS G 4053 (2003) Steel prepares gear material, implements the surface treatment such as carburizing to the gear material to manufacture.However, due to such gear simultaneously The use under high stress is not resistant to, so by the change of steel, the change of heat treatment method, or even adding by surface Work cure process etc. realizes the raising of tooth root bending-fatigue strength and corrosion resistance.
For example, patent document 1 discloses following method, i.e. by reducing the Si in steel, and control Mn, Cr, Mo and Ni, so that reduce the oxydic layer of grain boundary on the surface after carburizing heat treatment and reduce the generation of cracking, and by suppressing incomplete The generation of layer is quenched, suppresses the reduction of case hardness, so as to improve fatigue strength, and then adds Ca to control to encourage the production being cracked The raw MnS propagated extension.
In addition, Patent Document 2 discloses using the steel for the Si that with the addition of 0.25~1.50% as material, improve anti- The method of temperability.
In addition, to the part material of the automobile that manufactures bar cold forming etc., it is desirable to high forging.Therefore, implement Spheroidizing is heat-treated and by carbide spheroidizing, improves forging.
For example, patent document 3 discloses that following method, i.e. by roll the organizational controls of former state state, and in fact Spheroidizing is carried out after applying the stretching drawing processing that draft is more than 28%, so that it is low to obtain the hardness after spheroidizing And the steel of homogeneous hardness.
Patent document 1:Japanese Patent Publication 07-122118 publications
Patent document 2:No. 2945714 publications of Japanese Patent No.
Patent document 3:No. 4392324 publications of Japanese Patent No.
The content of the invention
However, there is problem as described below in the technology described in above-mentioned patent document 1,2 and 3.
That is, according to patent document 1, by reducing Si, oxydic layer of grain boundary and incomplete quenching layer are reduced, so can suppress The flexural fatigue cracking of tooth root is produced.However, if only simple reduce Si, anti-temper softening declines.As a result, due to nothing Method suppresses the temper softening caused by the frictional heat in the flank of tooth and softens surface, easily corrodes so existing, destruction Generation moves to this problem in flank of tooth side from tooth root.
In patent document 2, make the increase of Si amounts in order to improve anti-temper softening, but in this case, change during cold working Shape drag increases, and is not suitable for the purposes of cold forging.
In addition, in patent document 3, needing to implement this unnecessary process of stretch process before spheroidizing, causing into This increase.
Moreover, tissue, hardness after the morphology influence spheroidizing heat treatment of the micro-assembly robot of rolling former state state.Particularly compare In the case of thicker ferrite+pearlitic structrure, the control range for obtaining appropriate spheroidizing tissue is narrow, so depositing The problem of the tissue stablized is difficult to.
The present invention is to develop and complete in view of the above circumstances, it is therefore intended that provide a kind of carburizing steel and its favourable Manufacture method, bending fatigue strength and surface pressing of the bending fatigue strength higher than existing gear of the tooth root of the carburizing steel Fatigue properties are also excellent, are suitable for use as the material of high-strength gear etc., and can relatively easily obtain spheroidizing with low cost and move back Fire tissue, and forging is excellent and being capable of mass production.
And then, the result that inventor etc. furthers investigate repeatedly in order to solve above-mentioned problem has obtained following opinion.
A) by the way that Si, Mn and Cr amount in steel are rationalized, it is possible to increase anti-temper softening, also, utilization should Rationalize and suppress to soften because of caused by the heating on Gear Contact Surface, then can suppress the flank of tooth occurred during gear driving Cracking is produced.
B) to the oxydic layer of grain boundary for the starting point that can turn into flexural fatigue and fatigue cracking, add Si more than a certain amount of, Mn and Cr, the then density that the direction of growth of oxydic layer of grain boundary is changed into surface from depth direction increases direction.Therefore, because not having As the oxide layer grown as starting point along depth direction, so being difficult to turn into flexural fatigue and the starting point of fatigue cracking.
C) as described in above-mentioned a and b, Si, Mn and Cr have to the raising of anti-temper softening and the control of oxydic layer of grain boundary Effect, but for these effects that get both, to Si, Mn and Cr, it is necessary to strictly control its content.
D) in order to promote carbide spheroidizing, improve forging, it is necessary to strictly control C, Si, Mn and Cr content. Particularly effective is a large amount of addition Cr.
E) in order to stably obtain the spheroidizing of carbide, it is important that the tissue for rolling former state state is made small Ferrite-Perlite structure.Therefore, the spheroidizing heat treatment condition shown in Fig. 1 is used to be heated at high temperature rolling stock (1140 DEG C, thick Ferrite-Perlite structure) and low-temperature heat rolling stock (950 DEG C of heating, small ferrite-pearlite group Knit), trial is evaluated the hardness after the heat treatment.On the evaluation result, show annealing keeping temperature to ball in Fig. 2 The influence of hardness after shape annealing.When understanding heating-up temperature height and being organized as thick Ferrite-Perlite structure, with heating The low small Ferrite-Perlite structure of temperature is compared, and integral hardness is high, also, region of the vickers hardness hv below 130 only exists Very narrow and small temperature range can be realized.When especially annealing keeping temperature is low temperature, low-temperature heat rolling stock is favourable.
It should illustrate, the basis for meeting important document described later and optimum condition is contained for experiment steel.
F) moreover, micro-assembly robot has an impact to forging, and the micro-assembly robot is by before above-mentioned spheroidizing condition and annealing The strong influence of tissue.That is, for being organized before the annealing, point rate and ferrite on Ferrite-Perlite structure have been carried out The investigation of particle diameter.
The influence organized before spheroidizing to the forging after spheroidizing processing (765 DEG C -8 hours) is shown in Fig. 3, such as Shown in figure, it is known that by controlling to organize before spheroidizing, specifically, make total tissue point rate of ferrite and pearlite For more than 85%, and ferritic average grain diameter is set to be less than 25 μm, it is plain so as to obtain the steel with excellent forging Material.
It should illustrate, in the experiment shown in Fig. 3, limit upsetting rate refers to cylinder upsetting using stamping machine, in end Upsetting rate when rupturing.In addition, the composition of steel is identical with the composition of above-mentioned Fig. 2 experiment.
The present invention is completed based on above-mentioned opinion.
That is, idea of the invention constitutes as follows.
1. a kind of carburizing steel, is contained with the scope for meeting following formula (1), (2) and (3)：
In terms of quality %, C：0.1~0.35%, Si：0.01~0.22%, Mn：0.3~1.5%, Cr：1.35~ 3.0%th, P：Less than 0.018%, S：Less than 0.02%, Al：0.015~0.05%, N：0.008~0.015% and O： Less than 0.0015%, remainder is the composition of Fe and inevitable impurity, also, ferrite and pearlite in structure of steel Total tissue point rate be more than 85%, and ferritic average grain diameter is less than 25 μm；
3.1 >={ ([%Si]/2)+[%Mn]+[%Cr] } >=2.2--- (1)
[the %Cr] >=3.0--- (2) of [%C]-([%Si]/2)+([%Mn]/5)+2
2.5 >=[%Al]/[%N] >=1.7--- (3)
Wherein, [%M] is the content (quality %) of element M.
Should illustrate, above-mentioned carburizing steel for Carburization Treatment post-processing into various parts shape cold forging.It is preferred that Carry out spheroidizing before the cold forging, but processing capacity as needed etc., can also without spheroidizing situation Under for cold forging.
2. the carburizing steel as described in above-mentioned 1, above-mentioned steel further contains：In terms of quality %, selected from Cu：Less than 1.0%, Ni：Less than 0.5%, Mo：Less than 0.5%, V：Less than 0.5% and Nb：It is one kind or two or more in less than 0.06%.
3. a kind of manufacture method of carburizing steel, by the steel material with consisting of, is heated to more than 1160 DEG C and small Hot-working is carried out in 1220 DEG C, in Ar3The temperature province of the point above temporarily terminates hot-working, is cooled to less than 450 DEG C, then It is again heated to the temperature more than 900 DEG C and for less than 970 DEG C and starts again at hot-working, the total reduction after heating again Terminate hot-working under conditions of more than 70%, afterwards, 800~500 DEG C of temperature province is entered with 0.1~1.0 DEG C/s speed Row cooling；The steel material is contained in the scope for meeting following formula (1), (2) and (3)：In terms of quality %, C：0.1~ 0.35%th, Si：0.01~0.22%, Mn：0.3~1.5%, Cr：1.35~3.0%, P：Less than 0.018%, S：0.02% with Under, Al：0.015~0.05%, N：0.008~0.015% and O：Less than 0.0015%, remainder is Fe and inevitable Impurity composition；
3.1 >={ ([%Si]/2)+[%Mn]+[%Cr] } >=2.2 --- (1)
[%C]-([%Si]/2)+([%Mn]/5)+2 [%Cr] >=3.0 --- (2)
2.5 >=[%Al]/[%N] >=1.7 --- (3)
Wherein, [%M] is the content (quality %) of element M
4. the manufacture method of carburizing steel as described in above-mentioned 3, above-mentioned steel material further contains：In terms of quality %, it is selected from Cu：Less than 1.0%, Ni：Less than 0.5%, Mo：Less than 0.5%, V：Less than 0.5% and Nb：1 kind or 2 in less than 0.06% More than kind.
, such as, can be in the process with cold forging with mass production in the case of being processed into gear according to the present invention Flexural fatigue to tooth root is excellent, and the surface pressing fatigue properties also excellent carburizing steel of the flank of tooth.
Brief description of the drawings
Fig. 1 is the figure for the heat treatment condition for representing spheroidizing heat treatment.
Fig. 2 is the figure for the influence for representing annealing keeping temperature to the hardness after spheroidizing heat treatment.
Fig. 3 is the figure for representing to organize the influence to the forging after spheroidizing processing before spheroidizing.
Fig. 4 is the figure for the heat treatment condition for representing spheroidizing heat treatment.
Embodiment
Hereinafter, the present invention is illustrated.
First, in the present invention, illustrated to the composition of steel material is constituted into the reasons why being limited to above range.It should say Bright, " % " involved by composition means that quality % unless otherwise specified.
C：0.1~0.35%
In order to using the quenching after Carburization Treatment come the hardness of core in improving, it is necessary to more than 0.1% C, but if containing Amount is more than 0.35%, then the toughness reduction of core, so C amounts are limited to 0.1~0.35% scope.Preferably 0.1~0.3% Scope.
Si：0.01~0.22%
Si is to improve the softening that 200~300 DEG C of the temperature province that gear etc. can reach in rotation is thought in resistance Element, in order to play the effect, it is necessary at least add 0.01%.It is preferred that addition more than 0.03%.However, on the other hand, Si is Ferrite stabilizer, so being excessively added makes Ac3Transient point rises, in the content of carbon in the range of common hardening heat Easily there is ferrite in low core, and its result will cause the reduction of intensity.In addition, being excessively added makes the steel before carburizing hard Change, there is the drawback for deteriorating forging.From this point to consider, because Si amounts are if less than 0.22%, then do not produce above-mentioned Drawback, so Si amounts are limited to 0.01~0.22% scope.Preferably 0.03~0.22% scope.
Mn：0.3~1.5%
Mn is the element effective to hardenability, it is necessary at least add 0.3%.However, Mn easily forms carburizing abnormal layer, and And being excessively added increases remained austenite content, causes hardness to reduce, so the upper limit is set into 1.5%.Preferably 0.4~ 1.2% scope.More preferably 0.6~1.2% scope.
Cr：1.35~3.0%
Raisings of the Cr not only to hardenability is effective, is also the effective element of the raising to anti-temper softening, if content Less than 1.35%, then its additive effect is not enough.On the other hand, if it exceeds 3.0%, then the effect saturation of softening resistance is improved, Carburizing abnormal layer is easily formed, so Cr amounts are limited to 1.35~3.0% scope.Preferably 1.35~2.6% scope.
P：Less than 0.018%
P is in grain boundary segregation, and making the toughness of carburized layer and core reduces, therefore is mixed into more few better, but allow to Untill 0.018%.Preferably less than 0.016%.Typically, it is difficult to make content be 0%, but it is preferably 0% if being possible to.
S：Less than 0.02%
S is present and the effective element of the raising to cutting ability as sulfide-based field trash.However, being excessively added is The key factor for causing fatigue strength to reduce, so the upper limit is set into 0.02%.From the viewpoint of cutting ability, it can contain More than 0.004%.
Al：0.015~0.05%
Al and N combines to form AlN, contributes to the miniaturization of austenite matrix particle, in order to obtain the effect, it is necessary to add More than 0.015%, preferably more than 0.018%.On the other hand, if content is more than 0.05%, encourage has to fatigue strength Harmful Al2O3The generation of field trash, so Al amounts are limited to 0.015~0.05% scope.Preferably 0.015~0.037% Scope.
N：0.008~0.015%
N and Al combines to form AlN, contributes to the miniaturization of austenite matrix particle.Therefore, appropriate addition by with Al The balance of amount is determined, in order to play the effect, it is necessary to add more than 0.008%.But, if be excessively added, during solidification Steel ingot produces bubble, causes the deterioration of forgeability, so the upper limit is set into 0.015%.Preferably 0.010~0.015% model Enclose.
O：Less than 0.0015%
O exists in steel as oxide system field trash, is the element for damaging fatigue strength, more few better, allow to Untill 0.0015%.Typically, it is difficult to make content be 0%, but if may if be preferably 0%.
More than, the appropriate compositing range of the basis of the present invention is illustrated, but in the present invention, each element is such as Fruit only meet above range, then it is still insufficient, for C, Si, Mn, Cr, Al and N, it is important to meet following formula (1), (2) and (3) relation.
3.1 >={ ([%Si]/2)+[%Mn]+[%Cr] } >=2.2 --- (1)
[%C]-([%Si]/2)+([%Mn]/5)+2 [%Cr] >=3.0 --- (2)
2.5 >=[%Al]/[%N] >=1.7 --- (3)
Wherein, [%M] is the content (quality %) of element M
Above-mentioned formula (1) is to influence the factor of hardenability and anti-temper softening, formula (1) if less than 2.2, then hardenability and The improvement of anti-temper softening is insufficient, and fatigue strength is insufficient.On the other hand, if it exceeds 3.1, then above-mentioned improvement effect Fruit not only saturation, also results in the deterioration of cold-workability.
In addition, above-mentioned formula (2) is the factor of the easness degree for the spheroidizing for influenceing carbide, by making formula (2) meet 3.0 More than, so that easily spheroidizing.By combining the opinion of the composition and above-mentioned e, f, it can obtain extremely excellent after spheroidizing Different forging.
Also, above-mentioned formula (3) be influence austenite matrix particle miniaturization factor, formula (3) if value be unsatisfactory for 1.7, then micronized effect is not enough, and fatigue strength is insufficient.On the other hand, if it exceeds 2.5, then the easy coarsening of crystal grain And fatigue strength is insufficient, and processability will be caused to reduce because of solid solution Al, solid solution N.
More than, the basis to the present invention is illustrated, but in the present invention, can basis on the basis of them Need suitably to contain composition as described below.
Cu：Less than 1.0%
Cu improves effective to the intensity of mother metal, if content is more than 1.0%, produces red brittleness, the surface texture of steel It will deteriorate, so being set to less than 1.0%.It is preferred that addition is more than 0.01%.
Ni：Less than 0.5%
Raisings of the Ni to the intensity and toughness of mother metal is effective, but because valency is high, so being set to containing less than 0.5%.It is preferred that Addition is more than 0.01%.
Mo：Less than 0.5%
Mo is such as Ni, and the raising to the intensity and toughness of mother metal is effective, but because valency is high, is set to containing less than 0.5%.Contain Amount can be less than 0.2%.It is preferred that addition is more than 0.05%.
V：Less than 0.5%
V, such as Si, is the element useful to improving anti-temper softening, if content is more than 0.5%, effect saturation, So containing less than 0.5%.It is preferred that addition is more than 0.01%.
Nb：Less than 0.06%
Nb, such as V, Si, is the element useful to improving anti-temper softening, if content is more than 0.06%, effect is satisfied With so being set to less than 0.06%.It is preferred that addition is more than 0.007%.
The composition of the remainder of steel material is Fe and inevitable impurity.It is small although not for example being specially to add B In 0.0003% or so, then it can contain as impurity.
In addition, on the basis of the adjustment that composition described above is constituted, in addition it is also necessary to before the spheroidizing of material Structure of steel is controlled.
Total tissue of ferrite and pearlite point rate：More than 85%
If the bainite point rate organized before spheroidizing is high, resistance of deformation increase, forging deteriorates, so needing Total tissue point rate of ferrite and pearlite is set to more than 85% to reduce bainite point rate.It should illustrate, the upper limit can Think 100%.
In the present invention, due to using the high steel of the hardenability for meeting above-mentioned formula (1) etc., being difficult in common manufacture method Ensure the amount of above-mentioned ferrite+pearlite, by adjusting heating-up temperature, total reduction and cooling velocity when rolling, so that Ferrite+pearlite can be realized：More than 85%.
Ferrite average grain diameter：Less than 25 μm
Organize to have a great impact to the characteristic after spheroidizing before spheroidizing.That is, if before spheroidizing The ferrite particle diameter of tissue is more than 25 μm, then the forging after spheroidizing processing deteriorates.Especially because to limit upsetting rate Influence is big, so ferritic average grain diameter is less than 25 μm.On technological thought, it is not necessary to special provision lower limit, but as existing Lower limit in reality is 5 μm or so.
Next, the manufacturing condition to the present invention is illustrated.
In present invention, it is desirable to the steel material constituted with above-mentioned preferred component is heated into 1160 DEG C less than 1220 After DEG C, in Ar3The temperature province of the point above terminates rolling, is temporarily air-cooled to less than 450 DEG C, is then again heated to more than 900 DEG C and less than 970 DEG C of temperature, after terminating hot rolling under conditions of the total reduction more than 70% after heating again, by 800~ 500 DEG C of temperature province is cooled down with 0.1~1.0 DEG C/s speed.
Hereinafter, to each treatment conditions are defined as above the reasons why, illustrates.
[steel material heating-up temperature (the 1st section)：1160 DEG C less than 1220 DEG C]
In the present invention, due to needing to make the abundant solid solutions of AlN again from the state for keeping solidifying, so steel material is heated to More than 1160 DEG C of temperature.But, if heating-up temperature is too high, occur oxidization burning loss, surface texture deterioration, fuel cost increasing Plus etc., so the 1st section of heating-up temperature is set to be less than 1220 DEG C.
[in Ar3The temperature province hot-working of the point above is temporarily cooled to less than 450 DEG C after terminating]
In the hot procedure, preferably in hot-rolled process, ferrite-pearlite group is obtained to destroy cast sturcture Knit, in Ar3More than point terminate processing, be cooled to less than 450 DEG C.In addition, going out from the viewpoint for obtaining Ferrite-Perlite structure Hair, it is advantageous that hot-working is carried out with more than 50% reduction ratio.Cooling end temp need not especially set lower limit, as long as examining Consider heating cost etc. again and select actual value.The upper limit of hot worked reduction ratio is set also without special, as long as Consider machine utilization etc. to select the value of reality.
[steel material heating-up temperature (the 2nd section) again：More than 900 DEG C and for less than 970 DEG C]
In order to obtain spheroidizing tissue and soft, it is necessary to which the tissue for rolling former state state to be made to small iron element Body-pearlitic structrure, so being again heated to less than 970 DEG C of temperature.If it exceeds 970 DEG C, then AlN generations are thick separates out, On the other hand, if less than 970 DEG C, then small precipitation is carried out, it is also effective to coarse when suppressing carburizing.But, if It is that less than 900 DEG C of heating then AlN precipitation will become insufficient, so, the 2nd section of heating-up temperature is more than 900 DEG C.Preferably 920 More than DEG C.
[hot worked total reduction：More than 70%]
If the hot worked total reduction after heating again, i.e., the total amount of the reduction ratio of the manufacturing procedure after heating again Few, then crystal grain becomes thick and after cooling ferrite point rate and reduced, and big particle is not only easily produced during carburizing, processes material The hardness of material also rises, so being set to more than 70%.The upper limit of reduction ratio need not especially be set, as long as considering machine utilization etc. And select actual value.
It should illustrate, the reduction ratio, the slip of thickness is referred in the case where being plate using steel obtained by hot-working, Another aspect steel be bar steel, wire rod in the case of refer to draft.
[the cooling velocity of 500~800 DEG C of temperature province：0.1~1.0 DEG C/s]
In cooling procedure after hot-working, if the cooling velocity of 800~500 DEG C of temperature province is unsatisfactory for 0.1 DEG C/s, Then ferrite particle diameter becomes big, as thick Ferrite-Perlite structure.On the other hand, if it exceeds 1.0 DEG C/s, then cool down Ferrite afterwards point rate is reduced, the line and staff control as bainite and ferrite-pearlite.Therefore, by the cold of the temperature province But speed is limited to 0.1~1.0 DEG C/s scope.
The carburizing steel obtained using above-mentioned preparation method is preferable to carry out spheroidizing, thereafter for cold forging.Spheroidizing It is preferred that at 760~820 DEG C implement 2~15 hours, even but the present invention 740~760 DEG C or so relatively low temperature ball Shape annealing, can also obtain excellent forging.It should illustrate, the tissue after spheroidizing is the stratiform pearl of tissue before making Tabular cementite in body of light disconnects the tissue of spheroidizing.Substrate microstructure is ferrite, but due to being protected in the heating period Hold as austenite and ferritic two phase region, thus it is basic inherit before organize.
By cold forging into the steel of defined component shape, carburizing heat treatment is implemented using general law.Portion after carburizing heat treatment The surface of part forms the tissue of martensite (being tempered martensite during temper) main body.
Embodiment
To there is the steel that various composition is constituted shown in table 1, melting is carried out in 100kg vacuum melting furnace, by slab with table 2 Shown hot-working condition and cooling condition implement rolling, and bar steel is made.That is, the heating-up temperature represented with table 2 is heated and carried out 1st section of hot-working, untill being cooled to less than 450 DEG C after, with the heating-up temperature shown in table 2, total reduction and cooling velocity bar Part is heated, rolled and cooled down, and is carried out the 2nd section of hot-working, is obtained bar steel.To obtained bar steel, carried out by following condition Tissue point rate and ferrite average grain diameter, cold-workability, spheroidizing heat-treatability, carburizing portion characteristic and fatigue properties are commented Valency.
(1) tissue point rate and ferrite average grain diameter
The 1/4D positions in the L directions section of bar steel are carried out after mirror ultrafinish, corroded with nital, to 400 Obtained photo is shot again and carries out image analysis, thus tries to achieve the tissue point rate (Line Integral rate) and iron element of ferrite+pearlite The average grain diameter of body.
(2) evaluation method of cold-workability (forging)
Cold-workability is evaluated with 2 projects of resistance of deformation value and limit upsetting rate.
That is, the surface 1/4D of the bar steel (diameter D) of former state state position is rolled from distance, diameter of sampling：10mm, height Degree：15mm test film, using 300t (3000kN) stamping machine, determines compressive load during 70% upsetting, uses Japanese plasticity Processing association carries the resistance of deformation assay method for restraining compression based on end face sung and tries to achieve resistance of deformation value.
Limit upsetting rate is compressed processing using the method for determining resistance of deformation, by the upsetting when end ruptures Rate is used as limit upsetting rate.
When resistance of deformation value is that below 918MPa, limit upsetting rate are more than 76%, then it may be said that cold-workability is good.
(3) evaluation method of spheroidizing heat-treatability
Spheroidizing heat-treatability be heat-treated with spheroidizing after hardness, 3 items of resistance of deformation value and limit upsetting rate Mesh is evaluated.
That is, in the same manner as the evaluation of the cold-workability of above-mentioned (2), the bar steel (diameter D) of former state state is rolled from distance Surface 1/4D position, diameter of sampling：10mm, height：15mm test film, implements after spheroidizing heat treatment to the test film, Try to achieve resistance of deformation value and limit upsetting rate.Spheroidizing heat treatment is, with 2 conditions (A) shown in Fig. 4 and (B) progress, to use Vickers Hardness test (load：98N (10kgf)) determine at 9 points, try to achieve average value and maximum.As long as the hardness after spheroidizing heat treatment Average value to be less than HV130 and maximum be below HV135, then it may be said that forging is very excellent, and its stability is also excellent It is different.
As long as in addition, the resistance of deformation value after spheroidizing heat treatment (condition (A)) is below 890MPa and limit upsetting Rate is more than 80%, then it may be said that cold-workability is good.
(4) evaluation method of carburizing portion characteristic
In 930 DEG C, 7 hours, carbon potential：0.8% condition is implemented after carburizing, and big particle is produced to be whether there is in carburizing portion With this 2 project appraisal carburizing portion characteristics of grain boundary oxidation depth.
That is, in carburizing portion, zero will be designated as without the situation for producing big particle, there is the situation for producing big particle to be designated as ×。
By using the surface of the test film after observation by light microscope Carburization Treatment, determine grain boundary oxidation depth to evaluate Grain boundary oxidation movement.That is, multiplying power is used：400 times of observation by light microscope, try to achieve the maximum grain boundary oxidation depth in each visual field, will The average value in 10 visuals field is used as grain boundary oxidation depth.
Big particle is produced as long as no in carburizing portion, grain boundary oxidation depth is less than 10 μm, then it may be said that carburizing portion is special Property is excellent.
(5) evaluation method of fatigue properties
Fatigue properties rotary bending fatigue test piece and surface fatigue intensity this 2 project appraisals.
That is, from the bar steel of rolling former state state, test film for evaluating rotary bending fatigue is processed and for evaluation table The roller corrosion test piece of face fatigue strength, for experiment.In 930 DEG C, 7 hours, carbon potential：These are tested under conditions of 0.8% Piece is implemented after carburizing, at 180 DEG C, implements the heating temper of 1 hour.
Rotary bending fatigue test is with rotating speed：1800rpm is implemented, with 107Secondary time intensity is evaluated.
Roller corrosion test is in slip rate：40%, oil temperature：With 10 under conditions of 80 DEG C7Secondary time intensity is evaluated.
As long as rotary bending fatigue intensity is more than 806MPa, surface fatigue intensity is more than 3250MPa, then it may be said that tired Labor intensity is good.
It the obtained results are shown in table 3.
Table 2
※ underscores portion is outside optimum range
As shown in table 3, it is known that the example obtained according to the present invention, roll after former state state and spheroidizing heat treatment Cold-workability is excellent, and grain boundary oxidation depth as shallow, does not produce big particle in carburizing portion, moreover, compared with comparative example, rotation Bending fatigue strength and surface pressing fatigue strength are excellent.
Industrial applicability
According to the present invention, it is possible to provide cold-workability is excellent and rotary bending fatigue intensity and surface pressing fatigue strength are excellent Carburizing steel.Thus, for example when being processed into gear, the bending of tooth root can be obtained with mass production in the process with cold forging The carburizing steel of the surface pressing excellent in fatigue characteristics of fatigue properties and the flank of tooth.

Claims (2)

1. a kind of carburizing steel, it is characterised in that contain in the scope for meeting following formula (1), (2) and (3)：
In terms of quality %, C：0.1~0.35%, Si：0.01~0.22%, Mn：0.3~1.5%, Cr：1.35~3.0%, P： Less than 0.018%, S：Less than 0.02%, Al：0.015~0.05%, N：0.008~0.015% and O：Less than 0.0015%,
Remainder is the composition of Fe and inevitable impurity, also, ferrite in structure of steel and pearlite is total Tissue point rate is more than 85%, and ferritic average grain diameter is less than 25 μm；Also, after the carburizing heat treatment under the conditions of following 107Secondary rotary bending fatigue intensity be more than 806MPa, and the carburizing heat treatment after in slip rate：40%, oil temperature：80 10 under conditions of DEG C7Subsurface fatigue strength is more than 3250MPa；
3.1 >={ ([%Si]/2)+[%Mn]+[%Cr] } >=2.2 --- (1)
[%C]-([%Si]/2)+([%Mn]/5)+2 [%Cr] >=3.0 --- (2)
2.5 >=[%Al]/[%N] >=1.7 --- (3)
Wherein, [%M] is the content of the element M in terms of quality %；
Carburizing heat treatment condition is
Carburizing：930 DEG C, 7 hours, carbon potential：0.8%,
Tempering：180 DEG C, 1 hour.
2. carburizing steel according to claim 1, wherein, further contain：In terms of quality %, selected from Cu：1.0% with Under, Ni：Less than 0.5%, Mo：Less than 0.5%, V：Less than 0.5% and Nb：It is one kind or two or more in less than 0.06%.
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JP6057626B2 (en) * 2012-09-04 2017-01-11 山陽特殊製鋼株式会社 Machine structural steel with low heat treatment deformation
JP6241136B2 (en) * 2013-08-26 2017-12-06 新日鐵住金株式会社 Case-hardened steel
JP6225613B2 (en) * 2013-09-30 2017-11-08 新日鐵住金株式会社 Case-hardened steel
JP6143355B2 (en) * 2013-10-22 2017-06-07 株式会社神戸製鋼所 Hot-rolled steel sheet with excellent drawability and surface hardness after carburizing heat treatment
JP6197761B2 (en) * 2014-07-24 2017-09-20 Ｊｆｅスチール株式会社 Manufacturing method of cold processed products
JP2016098426A (en) * 2014-11-26 2016-05-30 山陽特殊製鋼株式会社 Case hardened steel for mechanical structure excellent in pitching resistance used for carburization case
JP2016169433A (en) * 2015-03-13 2016-09-23 株式会社神戸製鋼所 Steel sheet for carburization excellent in cold workability and toughness after carburization heat treatment
JP6558016B2 (en) * 2015-03-26 2019-08-14 日本製鉄株式会社 Carburized machine structural parts
KR101705168B1 (en) * 2015-04-20 2017-02-10 현대자동차주식회사 Carburizing alloy steel improved durability and the method of manufacturing the same
JP6319212B2 (en) * 2015-07-09 2018-05-09 Ｊｆｅスチール株式会社 Gear part and manufacturing method of gear part
JP6794012B2 (en) * 2015-12-10 2020-12-02 山陽特殊製鋼株式会社 Mechanical structural steel with excellent grain coarsening resistance, bending fatigue resistance, and impact resistance
WO2018151324A1 (en) 2017-02-20 2018-08-23 新日鐵住金株式会社 Steel sheet and manufacturing method therefor
CN107217210A (en) * 2017-07-27 2017-09-29 陈海燕 A kind of pinion steel
CN108165883A (en) * 2018-01-22 2018-06-15 弗兰德传动系统有限公司 20crmnmo steel and its processing method
JP7152832B2 (en) * 2018-06-18 2022-10-13 株式会社小松製作所 machine parts
JP2019011510A (en) * 2018-08-20 2019-01-24 株式会社神戸製鋼所 Steel sheet for carburization excellent in cold workability and toughness after carburization heat treatment
CN110846580B (en) * 2019-12-05 2021-09-07 马鞍山钢铁股份有限公司 high-Mo high-performance Mn-Cr series steel for wind power output gear and production method thereof
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CN114574768A (en) * 2022-03-15 2022-06-03 中新(重庆)超高强材料研究院有限公司 Niobium-vanadium composite microalloying and high contact fatigue performance gear steel for automobile and manufacturing method of gear

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2945714B2 (en) 1990-05-15 1999-09-06 日産自動車株式会社 High surface pressure gear
JPH07122118A (en) 1993-10-27 1995-05-12 Akira Suzuki Electrically conductive organic ultra-thin film
JPH1112684A (en) * 1997-06-19 1999-01-19 Kobe Steel Ltd Case hardening steel for cold forging
DE69811200T2 (en) * 1997-07-22 2003-10-09 Nippon Steel Corp TEMPERED STEEL WITH EXCELLENT PREVENTION OF SECONDARY RECRISTALIZATION DURING CARBONING, METHOD FOR THE PRODUCTION THEREOF, SEMI-PRODUCT FOR PARTS TO BE CARBONED
JP3409055B2 (en) * 1998-10-16 2003-05-19 浦項綜合製鐵株式会社 Wire for high-strength steel wire with excellent drawability and method for producing high-strength steel wire
JP3954772B2 (en) * 2000-04-26 2007-08-08 新日本製鐵株式会社 Shaped material for high-temperature carburized parts with excellent grain coarsening prevention characteristics and manufacturing method thereof
JP4392324B2 (en) 2004-10-28 2009-12-24 株式会社神戸製鋼所 Method for producing case-hardened steel for cold forging
WO2010082481A1 (en) * 2009-01-16 2010-07-22 新日本製鐵株式会社 Case hardening steel, carburized component, and method for producing case hardening steel
JP5332646B2 (en) * 2009-01-23 2013-11-06 Ｊｆｅスチール株式会社 Manufacturing method of carburizing steel with excellent cold forgeability
JP5495648B2 (en) * 2009-03-17 2014-05-21 山陽特殊製鋼株式会社 Machine structural steel with excellent grain coarsening resistance and method for producing the same

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