CN103620081B - Steel work and manufacture method thereof - Google Patents
Steel work and manufacture method thereof Download PDFInfo
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- CN103620081B CN103620081B CN201280031158.4A CN201280031158A CN103620081B CN 103620081 B CN103620081 B CN 103620081B CN 201280031158 A CN201280031158 A CN 201280031158A CN 103620081 B CN103620081 B CN 103620081B
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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
- C23C8/24—Nitriding
- C23C8/26—Nitriding 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
- C23C8/02—Pretreatment of the material to be coated
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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
- C23C8/80—After-treatment
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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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
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Abstract
The invention provides and have excellent erosion resistance and the steel work of cementability concurrently.Described steel work is the steel work being formed with nitride compound layer and nitrogen diffused layer on the top layer of the mother metal as steel, above-mentioned nitride compound layer is included in the first compound layer that nitrogen diffused layer side is formed and the second compound layer formed in the face side of above-mentioned first compound layer, and above-mentioned first compound layer is with Fe
3n is the layer of the epsilon structure of main body, and above-mentioned second compound layer is that nitrogen concentration is higher and form irregular layer on surface compared with the first compound layer.There is excellent cementability and carbon content is few and nitride compound layer that erosion resistance is high thereby, it is possible to formed.
Description
Technical field
The present invention relates to steel work and manufacture method thereof, described steel work is the surface treatment by implementing steel with nitriding treatment, erosion resistance and cementability can be made to improve, and the backing metal (Li gold by being applied to such as brake facing, brake-shoe, clutch plate etc.), the goods that its weather resistance improves can be made.
Background technology
Friction materials is bonded in the component obtained on the steel of backing metal by the friction members such as the brake facing used in automobile etc., brake-shoe, clutch plate generally most use.The bonding force of friction materials and backing metal and the performance of stopper, correlation of attributes are also very important factors from secure context.
In order to obtain the strong bonding force to friction materials, long ago just start to adopt methods such as utilizing shot-peening to make the method for the face roughening of backing metal.In addition, if bonding interface gets rusty, then bonding force can significantly reduce, and therefore also on the basis considering erosion resistance, implements to form the process (example patent documentation 1 described as follows) that zinc phosphate etc. changes into tunicle and undercoat.
But the tunicle etc. that changes into as described above has problems in thermotolerance, exists and causes erosion resistance and adaptation to reduce such problem because of heat.For stopper, clutch coupling, the characteristic that erosion resistance, adaptation reduce when producing large heat of friction is extremely unsatisfactory.
On the other hand, in order to make to comprise the mechanical component of various steel, the wearability of structural member, weather resistance improve, in field widely, use nitriding treatment.Wherein also knowing: for the steel except stainless steel, by forming nitride compound layer on its surface, can erosion resistance be improved.As one of its purposes, such as, be applied to the backing metal of brake facing.Backing metal after nitriding treatment is implemented to the steel except stainless steel, and is formed compared with the above-mentioned backing metal changing into tunicle, more favourable in erosion resistance.Therefore, the backing metal (example patent documentation 2 described as follows) gas soft nitriding process being applied to brake facing is investigated.
But when utilizing nitriding treatment to form backing metal, making erosion resistance improve if only form nitride compound layer simply on surface, is then insufficient.In order to improve cementability when making the mat material (パ ッ De material) as friction materials bonding, need to be formed micron-sized concavo-convex on its surface.
At this, salt Bath Nitriding Treatment is easy to form more concavo-convex surface, is therefore applied to backing metal (such as patent documentation 3).In salt Bath Nitriding Treatment, in the same manner as the nitride formed by common gas soft nitriding process, form Fe-C-N based compound.Therefore, in the same manner as patent documentation 2, cannot say in erosion resistance it is sufficient.
Prior art document
Patent documentation
Patent documentation 1: Japanese Unexamined Patent Publication 5-346129
Patent documentation 2: Japanese Patent Publication 53-47218
Patent documentation 3: Japanese Laid-Open Patent Publication 62-261726
Summary of the invention
Invent problem to be solved
Describe in above-mentioned patent documentation 2: in order to improve the cementability with friction materials, and it is concavo-convex to form warty, cancellous projection etc.But, if by means of only general gas soft nitriding process, be then difficult to be formed cementability is fully improved concavo-convex, and its concrete method all do not mentioned.In addition, for the Fe-C-N based compound formed by gas soft nitriding process, in the erosion resistance of himself, be also insufficient in the purposes that the backing metal of brake facing is such.In addition, in the nitride compound layer formed by general gas soft nitriding process, usually form the defect arriving diffusion layer from surface, thus detrimentally affect is brought to erosion resistance.Owing to there is above-mentioned problem, therefore practical situation are: the application of gas nitriding in backing metal is not in progress as realistic problem.
On the other hand, in above-mentioned patent documentation 3, as the method forming Fe-C-N based compound, employ salt Bath Nitriding Treatment.Salt Bath Nitriding Treatment is different from the nitriding treatment of common use gas, is easily formed for guaranteeing the concavo-convex of adhesiveproperties on surface.On the other hand, because be solid-liquid reaction, so the matrix constituent such as Fe also carry out to the reaction of stripping in salt bath simultaneously.Therefore, the through defect arriving diffusion layer, compared with using the nitriding treatment of gas, is easier to be formed.Thus, in order to make the concavo-convex increase on surface and make erosion resistance improve compared with common salt Bath Nitriding Treatment, need to form magnetite layer on surface, easily can expect that this layer also needs quite thick thickness.
That is, when applying salt Bath Nitriding Treatment, especially in erosion resistance, being preferably formed thick zone of oxidation and defect being carried out sealing of hole, by the method, the raising of erosion resistance to a certain degree can be expected.But the intensity of Z 250 self is extremely low, if zone of oxidation is formed thicker, then in magnetite layer, propagate crack thus friction materials peel off possibility high.In addition, compared with gas nitriding process, through defect more, size is larger, therefore, and is not easy to carry out sufficient sealing of hole.Thus, even if form zone of oxidation as recorded in patent documentation 3, also cannot say and necessarily can obtain sufficient erosion resistance, therefore, absolutely not talkative is practical method.
On the other hand, also can study and use the good stainless steel of erosion resistance and its cementability is improved, or form the plating layer with intensity to a certain degree.But, practical situation be these methods remain cost high and be difficult to apply method.Therefore, strong needs develops technology erosion resistance and cementability being taken into account by less expensive method.
The present invention is the invention completed in view of situation as above, its object is to provide, and has steel work and the manufacture method thereof of excellent erosion resistance and cementability concurrently.
For solving the means of problem
In order to play nitriding treatment less expensive and the advantage that erosion resistance is high that use gas, on steel, forming the higher and upper layer that cementability is higher of erosion resistance simultaneously, carried out various research.It found that: after making halogens diffuse to the degree of depth on more than 1 μm, distance surface, nitriding treatment is carried out in the gas atmosphere of not carbonaceous sources, form nitride compound layer thus, as shown in Figure 1, this nitride compound layer comprises the first compound layer and the second compound layer, and this is two-layer and form, described first compound layer be formed in nitrogen diffused layer side with Fe
3n is the layer of the epsilon structure of main body, described second compound layer be the face side of above-mentioned first compound layer formed and compared with the first compound layer nitrogen concentration higher and be formed with the heterogeneous layer of concave-convex surface.And, judge that the nitride compound layer comprising above-mentioned 2 layers has high adhesion and erosion resistance concurrently, thus complete the present invention.
In addition, also known: when above-mentioned nitride compound layer is formed the zone of oxidation based on ferriferous oxide situation, to add shot peening by particulate and by removings such as unwanted nitride, oxide compound, oxynitrides on the surface, can further improve cementability and erosion resistance.
That is, will being intended to of steel work of the present invention, it is the steel work being formed with nitride compound layer and nitrogen diffused layer on the top layer of the mother metal as steel,
Above-mentioned nitride compound layer comprises: the first compound layer formed in nitrogen diffused layer side and the second compound layer formed in the face side of above-mentioned first compound layer,
Above-mentioned first compound layer is with Fe
3n is the layer of the epsilon structure of main body,
Above-mentioned second compound layer is that nitrogen concentration is higher and form irregular layer on surface compared with the first compound layer.
In addition, will being intended to of the manufacture method of steel work of the present invention, after the fluoridation that fluorine is spread is implemented on its surface to steel, implements to make nitrogen carry out the gas nitriding process of spreading, thus forms nitride compound layer and nitrogen diffused layer on the top layer of mother metal, wherein,
Above-mentioned fluoridation comprises: while import fluorine source gas in process stove, while fluorine and steel are reacted fluoridize operation, keep heating with under the state of supply stopping fluorine source gas, make the fluorine being soaked in above-mentioned steel surface at least diffuse to the diffusing procedure of the degree of depth of more than 1 μm
In above-mentioned gas nitriding treatment, utilize the gas atmosphere of not carbonaceous sources to carry out reduction and the gasification of the fluorine composition after above-mentioned diffusion, and make nitrogen carry out diffusion to soak into form nitride compound layer and nitrogen diffused layer.
Invention effect
The above-mentioned nitride compound layer of steel work of the present invention comprises: the first compound layer formed in nitrogen diffused layer side and the second compound layer formed in the face side of above-mentioned first compound layer.Above-mentioned first compound layer is with Fe
3n is the layer of the epsilon structure of main body, and above-mentioned second compound layer is that nitrogen concentration is higher and form irregular layer on surface compared with the first compound layer.
About above-mentioned second compound layer, be formed with concave-convex surface, this concave-convex surface has the interrupted ditch portion of multiple prescribed depth.In addition, also externally grown by the nitride compound of Fe-N system and formed.In addition, be made up of the nitride that nitrogen concentration compared with the first compound layer is higher.Therefore, though such as at adhesive friction material and shear-stress large to this friction materials load, the concaveconvex shape on its surface is also difficult to be destroyed.
In addition, for the second compound layer of the formation concave-convex surface of Fe-N system and especially at the first compound layer of nitrogen diffused layer side formation, with the Compound Phase ratio of Fe-C-N system, erosion resistance is more excellent.In addition, based on the effect of fluoridation and gas nitriding process, become finer and close nitride compound layer, from surface, the existence of the through defect such to nitrogen diffused layer is few.Thus, the nitride compound layer that erosion resistance is extremely excellent is become.
In steel work of the present invention, when to have the degree of depth be to high-density the recess of more than 0.5 μm to the concave-convex surface of above-mentioned second compound layer,
The concaveconvex shape of the complexity that the degree of depth is more than 0.5 μm is formed at skin section, and it becomes the upper layer excellent in adhesion with friction materials etc.
In steel work of the present invention, when the surface nitrogen concentration of above-mentioned second compound layer is more than 12 quality %,
Making the surface nitrogen concentration of the second compound layer reach more than 12 quality % by improving nitrogen to the intrusion volume of skin section, forming the nitride compound of high N concentration, thus the external growth of nitride compound can be promoted.Thus, the concave-convex surface becoming the complexity of specific thickness is formed and the upper layer excellent in adhesion of itself and friction materials etc. in skin section.
In steel work of the present invention, when the thickness of above-mentioned second compound layer is more than 0.7 μm,
Making the thickness of the second compound layer reach more than 0.7 μm by improving nitrogen to the intrusion volume of skin section, forming the nitride compound of high N concentration, thus the external growth of nitride compound can be promoted.Thus, the concave-convex surface becoming the complexity of specific thickness is formed and the upper layer excellent in adhesion of itself and friction materials etc. in skin section.
In steel work of the present invention, when the thickness of above-mentioned first compound layer is more than 5 μm,
Nitride compound layer entirety becomes finer and close, and the existence of the through defect to nitrogen diffused layer becomes few, becomes the goods that erosion resistance is extremely excellent.
In steel work of the present invention, when the real surface of the per unit area on surface amasss than value for being greater than 1.8,
Real table area for apparent surface is amassed is very large, and the concavo-convex degree of concave-convex surface uprises just, thus can reliably guarantee stable adhesiveproperties.
In steel work of the present invention, under the zone of oxidation based on ferriferous oxide that the second compound layer forms thickness less than 3 μm is used as outermost situation,
Erosion resistance can be improved further.That is, for above-mentioned nitride compound layer, the concentration of the N of intrusion is also high, and the nitride compound layer particularly near the side of nitrogen diffused layer becomes finer and close compound layer.But, make through defect not be extremely difficult completely, and likely produce the rust as path.Therefore, by being covered by zone of oxidation, erosion resistance can be improved further.The nitride compound layer obtained based on the present invention possesses: a) compared with other nitriding method the erosion resistance of nitride compound layer self higher, b) can form on nitrogen diffused layer that dense compound layer, quantity c) easily becoming the through defect in the generation source of rust and volume are all few, such condition favourable for erosion resistance, therefore, only form the zone of oxidation of the thickness less than 3 μm not hindering cementability, just become and the major part of the through defect in nitride compound layer carried out sealing of hole and the very high upper layer of erosion resistance.Thus, such as, when being applied to the backing metal of brake-shoe, the stripping of the friction materials caused because there is corrosion effectively can be prevented.
In steel work of the present invention, when being present in the through defect in the second compound layer and being carried out sealing of hole by the oxide compound based on ferriferous oxide,
Erosion resistance can be improved further.That is, for above-mentioned nitride compound layer, the concentration of the N of intrusion is also high, and the nitride compound layer particularly near the side of nitrogen diffused layer becomes finer and close compound layer.But, make through defect not be extremely difficult completely, and likely produce the rust as path.Therefore, by being carried out sealing of hole by zone of oxidation, erosion resistance can be improved further.The nitride compound layer obtained based on the present invention possesses: a) compared with other nitriding method the erosion resistance of nitride compound layer self higher, b) can form on nitrogen diffused layer that dense compound layer, quantity c) easily becoming the through defect in the generation source of rust and volume are all few, such condition favourable for erosion resistance, therefore, only form the zone of oxidation of the thickness less than 3 μm not hindering cementability, just become and the major part of the through defect in nitride compound layer carried out sealing of hole and the very high upper layer of erosion resistance.Thus, such as, when being applied to the backing metal of brake-shoe, the stripping of the friction materials caused because there is corrosion effectively can be prevented.
For the manufacture method of steel work of the present invention, before gas nitriding process, implement that halogens is spread, soak into halogenated process to the degree of depth of more than 1 μm.Then, make this halogens and pass through NH
3the decomposition of gas and the reactive with active hydrogen produced, cause reduction reaction, thus be vaporized.Then, in not carbonaceous sources with NH
3gas is carry out nitriding treatment under the atmosphere of main body.Thus, can form the nitride compound layer with following concave-convex surface, described concave-convex surface has the interrupted ditch portion of multiple degree of depth more than 0.5 μm.
The general nitride compound layer formed by nitriding treatment, have as easy as rolling off a log be accommodated in around exist carbon, carbon in base material character.On the other hand, the carbon content of the nitride compound layer formed in the present invention is few.That is, do not become Fe-C-N system, and become the nitride compound layer of Fe-N system.Compared with forming the nitride compound layer of Fe-C-N system, the erosion resistance of the present invention forming the nitride compound layer of Fe-N system becomes extremely excellent.
Owing to being easy to form the concavo-convex of surface, therefore use salt Bath Nitriding Treatment also a lot of as the situation of the surface treatment method of backing metal at present.But in salt Bath Nitriding Treatment, use the compound of cyanogen system to carry out nitriding treatment, therefore, nitrogen is inevitable to spread with carbon simultaneously.Therefore, the carbon inevitably containing high density in the nitride compound layer on top layer, can judge that this situation plays disadvantageous effect for erosion resistance.
Therefore, in the present invention, employing uses the nitrogenize gas of not carbonaceous sources to carry out nitriding treatment.Thus, even if contain carbon with high density to a certain degree in the material, the nitride compound layer that carbon content is few and erosion resistance is high also can be formed.That is, in general nitriding treatment, carbon component contained in mother metal can not contain in nitride compound layer with keeping away.In the present invention, by the reduction of the diffusion of the fluorine in fluoridation and fluorine composition thereafter, surface is activated, thus N is more easily invaded.Surface after this activation, the active hydrogen produced by the decomposition of ammonia is promoted with the reaction of the carbon being present in nitride compound layer.By this reaction, carbon is removed in nitride compound layer with the form of hydrocarbon etc.
That is, by controlling the reduction of above-mentioned fluoridation and this fluorine composition, the interrupted ditch portion and complex-shaped, that cementability is high concave-convex surface with multiple degree of depth more than 0.5 μm can be formed.In the present invention, can by the surface treatment based on the gas nitriding process at the temperature of about less than 600 DEG C be formed above-mentioned concave-convex surface.Thus, the surface after fluorine composition is reduced becomes by the state activated, and the carbon concentration in nitride compound layer is reduced, thus can form the nitride compound layer of the high Fe-N system of erosion resistance.
In the manufacture method of steel work of the present invention, when repeating to fluoridize operation and diffusing procedure more than 2 times in above-mentioned fluoridation,
Fluorine can be made to spread to be soaked into the darker position of the skin section of steel, brings very large impact to the reduction of fluorine composition thereafter and gasification, can form the low and nitride compound layer that erosion resistance is high of carbon concentration very thickly.
In the manufacture method of steel work of the present invention, after stating gas nitriding process on the implementation,
Form the oxide skin based on ferric oxide of thickness less than 3 μm on surface, thus the through defect being present in nitride compound layer is carried out sealing of hole, in the case,
Erosion resistance can be improved further.That is, for above-mentioned nitride compound layer, the concentration of the N invaded is also high, and the nitride compound layer particularly near the side of nitrogen diffused layer becomes finer and close compound layer.But, make through defect not be extremely difficult completely, likely produce the rust as path.Therefore, by being carried out sealing of hole by oxide treatment, erosion resistance can be improved further.The nitride compound layer obtained based on the present invention possesses: a) compared with other nitriding method the erosion resistance of nitride compound layer self higher, b) can form on nitrogen diffused layer that dense compound layer, quantity c) easily becoming the through defect in the generation source of rust and volume are all few, such condition favourable for erosion resistance, therefore, only form the zone of oxidation of the thickness less than 3 μm not hindering cementability, just become and the major part of the through defect in nitride compound layer carried out sealing of hole and the very high upper layer of erosion resistance.Thus, such as, when being applied to the backing metal of brake-shoe, the stripping of the friction materials caused because there is corrosion effectively can be prevented.
In the manufacture method of steel work of the present invention, after stating gas nitriding process on the implementation,
Implementing the particulate shot peening that median size is less than 100 μm, by covering the removing such as unwanted nitride, oxide compound, oxynitride of outmost surface, making the concave-convex surface of the degree of depth more than 0.5 μm expose thus, in the case,
The bonding force of above-mentioned concave-convex surface can be made to improve further.That is, the nitride formed by nitriding treatment particle not with nitride compound layer fully in conjunction with time, or when concavo-convex by nitride, oxide compound, oxynitride covering surfaces, likely damage the adhesiveproperties of this part.Therefore, by implementing shot peening under weak condition, concave-convex surface can be made to expose, make bonding force more stable.
Above-mentioned shot peening is the process in order to improve cementability and adjustment sheet surface state further, can not remove the part of through defect sealing of hole by oxide treatment.Thus, not damaging the erosion resistance improved by implementing oxide treatment, can cementability be improved.
As mentioned above, steel work of the present invention and manufacture method less expensive are treated to main surface treatment method with gas nitriding by using, such as, can form cementability when making friction materials bonding high and extremely not easily produce the upper layer of rust.Therefore, such as, when being applied to the backing metal etc. of brake-shoe, through long-time, friction materials is not also peeled off, and becomes the goods of excellent in te pins of durability.
Accompanying drawing explanation
Fig. 1 is the schematic diagram representing the nitride compound layer of steel work of the present invention and the Rotating fields of nitrogen diffused layer.
Fig. 2 represents the N concentration of the skin section measuring embodiment and comparative example 1 and the figure of result that obtains.
Fig. 3 is the figure representing the surface of embodiment and comparative example 1,2 and the SEM observations of section.
Fig. 4 is the measurement result that embodiment and comparative example 2 are measured to surface shape and obtain.
Fig. 5 is the figure of the SEM observations on the surface of C2-2 and C2-3 represented as embodiment.
Embodiment
Next, illustrate for implementing mode of the present invention.
The steel work of present embodiment is the steel work being formed with nitride compound layer and nitrogen diffused layer on the top layer of the mother metal as steel.
Above-mentioned nitride compound layer comprises: the first compound layer formed in nitrogen diffused layer side and the second compound layer formed in the face side of above-mentioned first compound layer.
Above-mentioned first compound layer is with Fe
3n is the layer of the epsilon structure of main body, and above-mentioned second compound layer is that nitrogen concentration is higher and form irregular layer on surface compared with the first compound layer.
The manufacture method of the steel work of present embodiment is after implementing to the surface of steel the fluoridation making fluorine spread, implement the gas nitriding process that nitrogen is spread, thus form the manufacture method of the steel work of nitride compound layer and nitrogen diffused layer on the top layer of mother metal.
Above-mentioned fluoridation comprises: while import fluorine source gas in process stove, while fluorine and steel are reacted fluoridize operation, heat with maintenance under the state of supply stopping fluorine source gas and make the fluorine soaked at above-mentioned steel surface at least diffuse to the diffusing procedure of the degree of depth of more than 1 μm
In above-mentioned gas nitriding treatment, utilize the gas atmosphere of not carbonaceous sources to carry out reduction and the gasification of the fluorine composition after described diffusion, and nitrogen is spread soak into form nitride compound layer and nitrogen diffused layer.
As mentioned above, steel surface application being fluoridized to the fluoridation of the diffusing procedure of operation and fluorine, dark fluorinated layer can be formed when not making surface fluorine concentration rise excessively.And, by not carbonaceous sources with NH
3for the gas nitriding process of main body, form nitride compound layer.Thus, form the first compound layer of the few Fe-N system of through defect in nitrogen diffused layer side, be formed with the second compound layer of concave-convex surface in face side.Thus, can be made into the steel with all excellent upper layer of both cementability and erosion resistance.And, such as can use as the backing metal etc. of the brake facing, brake-shoe, clutch plate etc. of excellent in te pins of durability well.
Present embodiment can be applicable to the various steel that carbon steel, low alloy steel, high quality steel, structure rolled iron, high tension steel, steel for mechanical structure, carbon tool steel, alloy tool steel, high speed tool steel, bearing steel, spring steel, converted steel, nitriding steel, stainless steel, high temperature steel, casting forged steel etc. can form nitride compound layer.Wherein, structure rolled iron, high tension steel etc. can be preferably used to use as the backing metal of brake facing, brake-shoe, clutch plate etc.
For above-mentioned steel, first carry out halogenated process.
By this halogenated process, the oxidation overlay film on the surface of treated object is removed, form halogenated layer simultaneously.In addition, by carrying out the dehalogenate element process of the halogenic ingredient reduction in this halogenated layer and nitriding treatment, thus making from the surface of treated object nitrogen carry out diffusion to soak into, forming nitride compound layer and nitrogen diffused layer.
As above-mentioned halogenated process, fluoridation, chloridized, bromination process, iodine and iodide etc. can be enumerated, can preferably carry out disposing easily and be industrially easy to utilize fluoridation.
For above-mentioned fluoridation, such as, at NF
3gas etc. comprise in the fluorine source gas atmosphere of fluorine and/or fluorine cpd at 200 ~ 600 DEG C, keep heating specific time, are removed by the oxidation overlay film of steel surface, form the fluorinated layer comprising fluorochemical.
Now, iff in order to carry out nitriding treatment, as long as then form the fluorinated layer less times greater than the degree of the oxidation overlay film thickness formed at steel surface.That is, if oxide film thereon is replaced into fluorochemical, be then sufficient, specifically, formed less than 1 μm, form the fluorinated layer thinner than it in most instances.
On the other hand, in the present embodiment, formed more than 1 μm, more preferably the fluorochemical of about 1.5 ~ 4.5 μm and fluorine soak into layer.By making fluorine soak into so dark, thus such as comprising NH thereafter
3when heating under the atmosphere of gas, because of NH
3the decomposition of gas and the active hydrogen produced and fluorine react, and gasify, can form the concave-convex surface with multiple interrupted ditch portions.
Now, NH is utilized
3gas also carries out nitriding treatment concurrently, carries out formation and the nitriding treatment of concave-convex surface simultaneously, thus becomes and process more efficiently.By such process, the nitriding treatment layer comprising nitride compound layer and nitrogen diffused layer can be formed.Above-mentioned nitride compound layer comprises the first above-mentioned compound layer and the second compound layer and forms.
For the concave-convex surface of the second compound layer, preferably make the concave-convex surface of the recess to high-density with the degree of depth more than 0.5 μm, be more preferably more than 1 μm and less than 5 μm.If this is because the degree of depth of concave-convex surface is excessively shallow, then cannot obtain the cause of required adhesiveproperties.On the contrary, be due to following cause: if the degree of depth of concave-convex surface is excessively dark, then die down with the bonding force of the first compound layer, occur to peel off, thus there is the danger that adhesiveproperties declines.It should be noted that, for the recess of the above-mentioned degree of depth more than 0.5 μm, to there are more than 2 places in the every 50 μm of length (nominal length) preferably on surface, more preferably there are more than 3 places.
At this, the concentration of the fluorine source gas used in fluoridation is adjusted to suitable concentration according to material of treated object etc.At this, if the Funing tablet on treated object surface becomes too high, then during nitriding treatment, the part of generating gasification becomes too much, the surface element generation powder of nitride compound layer and cause cementability easily deteriorated.Therefore, the Funing tablet on the treated object surface before nitridation process sequence is preferably set to below 60 quality %, is more preferably set to below about 50 quality %.
Thus, with regard to the surface treatment method in the present invention, in order to not make the Funing tablet on treated object surface extremely rise, and fluorine is soaked into darker, and be provided with the diffusing procedure of fluorine.That is, arrange in fluoridation: fluoridize operation, in process stove, pass into certain hour fluorine source gas and treated object and fluorine are reacted; And diffusing procedure, stop the supply of fluorine source gas, keep heating certain hour, thus promote the diffusion of fluorine, and the Funing tablet of adjustment sheet face.Thereby, it is possible to do not make the Funing tablet on treated object surface exceedingly rise, and form deep fluorine soak into layer.
At this, above-mentioned fluoridation preferably repeats more than 2 times and fluoridizes operation and diffusing procedure.This is due to following cause: slowly, therefore, when the Funing tablet on surface occurs exceedingly to rise, by diffusion, its concentration is reduced needs for a long time the velocity of diffusion of the fluorine in steel, and efficiency can be deteriorated.
Specifically, be more preferably used in more than 200 DEG C, be divided into the method supplying fluorine source gas for several times at the temperature of preferably more than 300 DEG C, more preferably more than 400 DEG C.Like this, by repeating to fluoridize operation and diffusing procedure, the Funing tablet on treated object surface can be made not excessively to increase, and form deep fluorine soak into layer.
If comprise above-mentioned temperature of fluoridizing the fluoridation of operation and diffusing procedure less than 200 DEG C, then the velocity of diffusion of fluorine is slow, needs long-time, productivity variation in order to form the fluorinated layer of more than 1 μm.On the other hand, if the temperature of fluoridation is more than 600 DEG C, then the velocity of diffusion of fluorine rises, and on the other hand, the speed of response of fluorine and steel exceedingly rises, and becomes the Funing tablet being difficult to control material surface.Thus, the temperature of above-mentioned fluoridation is preferably set to more than 200 DEG C and less than 600 DEG C.
In above-mentioned fluoridation, if the degree of depth making fluorine spread is less than 1 μm, then the concavo-convex height formed on surface becomes insufficient, cannot improve the bonding force with friction materials etc. fully.On the other hand, if the depth of penetration of above-mentioned fluorine is greater than 5 μm, then the gas escaped quantity on surface becomes too much, and the porous on surface becomes fierce, and concaveconvex shape becomes easily destroyed, and easily causes powder.Thus, the degree of depth in above-mentioned fluoridation, fluorine being spread preferably is set to more than 1 μm and less than 5 μm.
For carrying out the time of fluoridizing operation and diffusing procedure, the machining state etc. according to material, surface suitably sets.If the treatment time less than 1 minute, is then difficult to make fluorine soak into fully.Otherwise if be greater than 120 minutes, then the depth of penetration of fluorine and the Funing tablet of surface element easily become superfluous, and production efficiency is also deteriorated in addition.Thus, the treatment time of fluoridation is preferably set to more than 1 minute and less than 120 minutes.
Above-mentioned fluoridation can also be implemented in the stove carrying out nitriding treatment, also can implement fluoridation and nitriding treatment in respective stove.In addition, fluoridation room and nitriding treatment room also can be set respectively in identical stove and implement process.Now, fluoridation and nitriding treatment are preferably separately implemented in different stoves or in room.This is because following cause: thus, be easy to control the Funing tablet of material surface and the depth of penetration of fluorine.
After implementing above-mentioned fluoridation, implement nitriding treatment.
Nitriding treatment is by comprising NH
3in atmosphere gas etc. source gas in nitridation, heating kept to the steel work after fluoridation and carry out.
By above-mentioned nitriding treatment, the nitride compound layer being included in the first compound layer that nitrogen diffused layer side formed and the second compound layer formed in the face side of above-mentioned first compound layer can be formed.Above-mentioned first compound layer is with Fe
3n is the layer of the epsilon structure of main body, and above-mentioned second compound layer is that nitrogen concentration is higher and form irregular layer on surface compared with the first compound layer.
Above-mentioned second compound layer is preferably set to the high N concentration that surface nitrogen concentration is more than 12 quality %.Thus, the second compound layer can become and is formed with concave-convex surface and the layer having given play to adhesiveproperties.Second compound layer with such concave-convex surface is formed as described below: make concavo-convex formation by carrying out defluorinate process to fluoridation layer, along the protuberance formed thus, makes nitride carry out external growth, thus is formed.The second compound layer now formed is the compound layer containing a great deal of, less with the first compound layer phase specific mass nitride compound, its result, can think and become the higher compound layer with complicated concaveconvex shape of adaptation.
The concave-convex surface of above-mentioned second compound layer is preferably set to the concave-convex surface of the recess to high-density with the degree of depth more than 0.5 μm.This is due to following cause: if the degree of depth of concave-convex surface is less than 0.5 μm, then likely cannot obtain enough adhesivepropertieies.
The condition optimization of nitriding treatment sets in the mode making the nitrogen concentration on surface and become more than 12 quality %.This is due to following cause: by will by NH
3decomposition and the active N that produces supplies in high concentration near surface, thus promote Fe in the mode attracted by this N from internal divergence to surface element.On the other hand, if make the nitrogen concentration on surface raise too high, then easily cause the reduction of the toughness on the second compound layer surface, therefore the preferred nitrogen concentration by surface is set to below 20 quality %.
In addition, the thickness of above-mentioned second compound layer is preferably set to more than 0.7 μm, is more preferably set to more than 1 μm.If the thickness of the second compound layer is less than 0.7 μm, be then difficult to improve bonding strength significantly.On the other hand, if the thickness of the second compound layer is greater than 5 μm, then the layer that nitrogen concentration is high is thickening and occur brittle, likely causes bonding strength to reduce on the contrary.Thus, preferably the thickness of the second compound layer is set to more than 0.7 μm and less than 5 μm.
Preferably the real surface of the per unit area on surface is amassed than being set to the value being greater than 1.8.This is due to following cause: by forming above-mentioned concave-convex surface, thus makes the long-pending increase of the real surface of per unit area, makes bond area increase thus, thus improves cementability.The real surface of per unit area amasss than referring to the value that value that real surface amasss is amassed divided by apparent surface and the numerical value obtained.
Above-mentioned real surface sum real surface amasss ratio such as the device by analyzing 3 D surface shape and measures.In addition, the length of the jog in certain section can be measured, utilize with the ratio of slant range to calculate the long-pending ratio of real surface.In addition, 3D image can be taken, be obtained by this shooting image.
If above-mentioned real surface is long-pending than being less than 1.8, then cannot expect the raising of significantly surperficial adaptation.On the other hand, if real surface is long-pending, than being greater than 5, the intensity that then above-mentioned second compound layer with concave-convex surface is combined with the first compound layer as its bottom likely reduces, and there is the danger that cementability reduces on the contrary.Therefore, preferred real surface amass than for be greater than 1.8 and be less than 5 value.In addition, make caking agent adhere to, be soaked in the whole region of convex-concave surface if also consider, then more preferably this value is more than 2 and less than 4.5.
Now, if nitrogen treatment temperature is lower than 450 DEG C, then soaked into fluorine is slack-off with the reaction of the hydrogen invaded from steel surface, and the formation speed of the second compound layer is also slack-off, thus productivity is deteriorated.Otherwise if be greater than 650 DEG C, then the growth of the second compound layer is too fast, extremely easily there is porous in the particularly skin section of the second compound layer, likely occurs that the intensity of the nitride compound formed reduces and do not tolerate the situation of actual use.Thus, preferably above-mentioned nitrogen treatment temperature is set to more than 450 DEG C and less than 650 DEG C.More preferably nitrogen treatment temperature is more than 500 DEG C and less than 600 DEG C.
By the time of above-mentioned nitriding treatment, thus show the concave-convex surface as the distinctive surface shape of the present invention.That is, make soaked into fluorine and hydrogen react and gasify, and make the second compound layer along inside and outside growth.And, considering erosion resistance, being preferably set to for making to be the sufficient time by the nitride compound layer growth that the first compound layer and the second compound layer combine and obtain for thickness more than 7 μm.Specifically, also determine according to the material of used mother metal, if be such as carbon steel, low alloy steel, high tension steel etc., be then preferably set to more than 10 minutes and within 3 hours.If the treatment time less than 10 minutes, be then difficult to formed needed for nitride compound layer and surface shape.In addition, this is due to following cause: namely, enters into compound layer and only concerning it carries out de-charcoal, be also inadequate time for carbon contained in material.Otherwise, be due to following cause: even if carry out the process being greater than 3 hours, performance also reaches capacity, and causes productivity to reduce.
In addition, the thickness of above-mentioned first compound layer is preferably made to be formed as about 5 μm.This is because form dense compound layer in the mother metal side of the first compound layer being formed in surface.
The nitride compound layer making the first compound layer and the second compound layer combine and obtain preferably is set to thickness more than 7 μm, if the erosion resistance of considering, is then more preferably more than 8 μm.On the other hand, if this thickness is greater than 25 μm, then the performance comprising erosion resistance is saturated, and easily forms thick porous layer on surface.Thus, the thickness of nitride compound layer is preferably set to more than 7 μm and less than 25 μm.If consider productivity in the scope substantially not reducing performance, then more preferably the upper limit of thickness is set to less than 20 μm.
As the nitrogenize gas used during above-mentioned nitriding treatment, be set to not containing the gas of gas possessing carburizing.This is to form the higher nitride compound layer of erosion resistance.Specifically, such as can exemplify and supply only NH
3gas, NH
3gas and nitrogen, NH
3gas and hydrogen, NH
3the method of gas and nitrogen and hydrogen.
Then above-mentioned nitridation process sequence, can implement surface oxidation operation as required.
By above-mentioned surface oxidation operation, form the oxide skin based on ferriferous oxide of thickness less than 3 μm as outermost layer.The object of this oxide treatment operation is, by above-mentioned oxide compound, the through defective part of nitrogen diffused layer of the through lower floor to being present in nitride compound layer is carried out sealing of hole.The method is not particularly limited, such as, can adopt the method carrying out being oxidized in the atmosphere containing the oxidation source gas such as aerobic or water vapour under the nitriding treatment that continues keeps heating condition.In addition, can be the method carrying out being oxidized in refrigerating work procedure, can also for first cooling the method that then maintenance heating is once again carried out being oxidized.
The outmost surface portion of the steel after utilizing method of the present invention to carry out nitriding treatment becomes and has micron-sized concavo-convex complicated shape, the through defect of the first compound layer formed in nitrogen diffused layer side is fewer, thus, even if do not implement so strong oxide treatment, also easily sealing of hole can be carried out.Thus, even if by utilizing the oxide treatment of the short period of time of refrigerating work procedure, also erosion resistance can be improved fully.
More particularly, being reduced to from the temperature of about 600 DEG C during about 200 DEG C in the temperature of processed product, by utilizing the atmosphere that there is the oxidation source gas such as oxygen and/or water vapour to cool, thus can being easy to erosion resistance is improved.Oxide treatment can also be implemented in lower temperature province, but in this case, need the time to a certain degree.Thus, preferably by the temperature more than 450 DEG C, be exposed to and comprise above-mentioned oxidation source gas 3 below capacity %, more preferably comprise in the atmosphere of 1 below capacity %, thus formed less than 3 μm with Fe
3o
4for the oxide skin of main body.
If above-mentioned oxide skin is greater than 3 μm, then when being such as applied with shear-stress when making friction materials bonding, producing in the oxide skin that intensity is low and destroying, easily causing the stripping of friction materials thus.Thus, preferably the thickness of formed oxide skin is set to less than 3 μm, is more preferably less than 1.5 μm.If be the method, then can form required oxide skin within the time of cooling of carrying out treated object, thus, also excellent in productivity.In addition, when forming above-mentioned oxide skin, in order to play this effect, preferably its thickness is set to more than 0.2 μm.
In the present embodiment, after gas nitriding process, particulate shot peening can be implemented as required.
Particulate shot peening utilizes median size to be the shot peening that the particulate of less than 100 μm carries out, and can then gas nitriding process carry out, and also can the oxide treatment then after gas nitriding process carry out.Thus, by covering the removing such as unwanted nitride, oxide compound, oxynitride of outmost surface, the concave-convex surface of the degree of depth more than 0.5 μm is exposed.
Namely, the object of above-mentioned oxide treatment is for carry out sealing of hole as described above by through defect, therefore, after the oxidising treat-ment, sometimes give fine concaveconvex shape to its surface further, or there is the part being formed with unwanted particle, nitride, oxide compound, oxynitride etc. in the mode covered on convex-concave surface.Under these circumstances, such as additionally use median size to be less than 100 μm, preferably the particulate such as the granulated glass sphere of less than 70 μm or ceramic particle, the shot peening of the pressure of about 0.1 ~ 0.4MPa.Thus, by by removings such as these particles, nitride, oxide compound, oxynitrides, thus the higher condition of surface of cementability can be become.
As mentioned above, formed on the surface of steel work and there is concave-convex surface and the second compound layer of excellent adhesion with the first compound layer, form the upper layer that cementability is high.In addition, form the first compound layer of the high Fe-N system of the few erosion resistance of through defect in mother metal side, erosion resistance is also improved.In addition, when additional formation do not hinder with the oxide treatment operation of the thin zone of oxidation of the cementability of friction materials etc., carry out for effects on surface state the shot peening operation adjusted, by the through defect sealing of hole existed a little in nitride compound layer, the surface-treated layer that erosion resistance is higher can be formed.
Thus, the surface-treated layer formed becomes the also excellent processing layer of erosion resistance that the high and deterioration of its cementability of cementability in surface shape is suppressed.Surface-treated steel work has been carried out for utilizing treatment process of the present invention, such as by being applied to the bonding backing metal etc. of the friction member such as brake facing, brake-shoe, clutch plate that uses in automobile etc., thus become the structural member with excellent weather resistance.
Next, embodiment is described.
Embodiment 1
As the steel for testing, the SS400 as general structure rolled sheet material, the SAPH440 as vehicle structure hot-rolled steel plate, SPFH590 as automobile processibility hot rolling high-tensile steel are prepared.
Embodiment: after being heated to 400 DEG C in the stove of the test film of above-mentioned 3 kinds of steel grades in nitrogen atmosphere, supply nitrogen dilution in stove and the NF of the 10 capacity % obtained
3gas, simultaneously implement 5 minutes fluoridize operation.Then, NF is stopped
3the supply of gas, carries out the fluoridation of the enforcement diffusing procedure of 15 minutes.Then, be heated to 500 DEG C, in stove, supply the NH of 70 capacity %
3the H of gas and 30 capacity %
2gas, implements the reduction (that is, defluorinate process) of the fluoridation layer of 20 minutes simultaneously.Then, be warming up to 550 DEG C, in stove, supply the NH of 70 capacity %
3the N of gas and 30 capacity %
2gas implements the nitriding treatment of 60 minutes, in nitrogen atmosphere, be cooled to room temperature.It should be noted that, for only implement above-mentioned fluoridize operation and diffusing procedure after just carry out the test film cooled under nitrogen atmosphere, investigate the thickness of fluorinated layer, confirm that arbitrary test film is all formed with the fluorinated layer of 1.5 ~ 2.0 μm.
The nitriding treatment product that comparative example 1(uses fluoridation in the past and obtains): after being heated to 400 DEG C in the stove of the test film of above-mentioned 3 kinds of steel grades in nitrogen atmosphere, supply nitrogen dilution in stove and the NF of 2.5 capacity % that obtains
3gas, implements the fluoridation of 20 minutes simultaneously.Then, be warming up to 550 DEG C, in stove, supply the NH of 70 capacity %
3the N of gas and 30 capacity %
2gas, carries out the nitriding treatment of 60 minutes, at room temperature cools in nitrogen atmosphere.It should be noted that, after implementing above-mentioned fluoridation, carry out cooled test film under nitrogen atmosphere, investigate the thickness of fluorinated layer, the fluorinated layer of arbitrary test film be 0.4 ~ 0.6 μm thick, confirm thinner than embodiment.
Comparative example 2(salt Bath Nitriding Treatment product): the test film also to have prepared SAPH440 to carry out at 570 DEG C after the salt Bath Nitriding Treatment of 40 minutes.
For above-mentioned test film, the rust area on the result obtained analyzing its surface and surface when carrying out temperature 60 C, the humidity moistening test of 80%, 100 hours in constant temperature and humidity cabinet is shown in following table 1.It should be noted that, specific surface area in table refers to and to make that real surface is long-pending to be increased area by generating the concavo-convex of surface relative to measuring, and the real surface calculated when carrying out three-dimensional measurement (such as can use the fine surface-profile measuring instrument of ZetaInstruments Inc. pan focus PLUS optical profile type 3D) to its actual surface-area amasss/measure the value of area ratio.
Table 1
As shown in Table 1, in an embodiment, any one steel grade all defines the low nitride compound layer of carbon concentration on surface.In addition we know, for comparative example 1,2, there is very high surface nitrogen concentration.
Fig. 2 represents that the concentration distribution of the depth direction of the N to the embodiment of SAPH440 material and the outmost surface portion of comparative example 1 measures and the result obtained.Known: the nitrogen concentration defining about 2 μm is in an embodiment greater than the part of 10 quality %, on the other hand, there is no in comparative example 1 and form part as described above.In addition, if observe the passing of the nitrogen concentration started from the surface of embodiment, then define and can think that nitrogen concentration is the ε (Fe of about 8 quality %
3n) first compound layer and can thinking of phase have in its side, top layer the high surface nitrogen concentration being greater than 11 quality % containing ζ (Fe
2n) the second compound layer of phase.Be formed as that N concentration in each layer slowly reduces from surface, so-called inclinations to form, the second compound layer is concave-convex surface layer, and high with the bonding force of the first compound layer below it, can think that it is can the layer of the strong stress of load.
Fig. 3 is the result of the surface of embodiment and comparative example 1, comparative example 2 and section being carried out to SEM observation.From this surperficial SEM photo, define the concave-convex surface of multiple trench in an embodiment with micron order.This surperficial SEM photo illustrates: for fluoridation method in the past, fluorine is only at surface enrichment, but by applying suitable DIFFUSION TREATMENT after this, then carrying out reduction and the nitriding treatment of fluorochemical, thus the concave-convex surface with multiple ditch portions can be formed.That is, by implementing to comprise the fluoridation of diffusing procedure, thus fluorine is soaked into darker, undertaken by making soaked into fluorine composition reducing, gasifying, thus form recess.By the residual part for convex from around invade N and realize high N concentration, thus promote the growth of the nitride of protuberance.Thus, from the section SEM photo of embodiment, the second compound layer formed can see obvious aberration compared with the first compound layer, from its this situation dark, is the layer of the light element containing a great deal of.It illustrates: become large by surface-area, thus from invading N around, become high N concentration, form the heterogeneous nitride different from the composition of the nitride in the first compound layer, and grow, thus, become the shape that concave-convex surface is more complicated.Thus, with regard to embodiment, compared with comparative example 1,2, the concave-convex surface that the value that forms specific surface area is significantly large can be thought.
This real surface is amassed to the surface layer structure of the embodiment added significantly, become the surface shape that cementability is extremely excellent by the increase effect of bond area.It should be noted that, the surface layer structure of this embodiment does not find large difference between kind of the steel grade of 3 for testing, this means the steel grade for other, also profit can use the same method to form dark fluorinated layer and carry out reducing, gasifying, thus forming same surface shape.
Second compound layer with concave-convex surface be made up of the nitride of this high N concentration is confirmed in the outmost surface portion of the section SEM photo of the embodiment of Fig. 3.The existence of this second compound layer brings very large impact to cementability.
In addition, about erosion resistance, embodiment is compared with comparative example 1,2, obviously more excellent.Can not think the cause of the nitride layer defining the low Fe-N system of carbon concentration simply, also demonstrating the first compound layer formed in the diffusion layer side of the second compound layer becomes the few extremely fine and close layer of through defect.
On the other hand, for the salt-bath nitriding product of comparative example 2, from surperficial SEM photo, define the nitride of convex on surface, thus make table roughness, specific surface area become large, improve bonding force.But from section SEM photo, the bonding state of the not talkative nitride of this convex and the nitride under it is good.Although confirm larger hole, can think compared with being formed with the situation of multiple concave-convex surface as the embodiment, closing force when applying shear-stress etc. is not by a long sight.In addition, as mentioned above, observe larger hole, can think that the through through defect to nitrogen diffused layer is also many.Known, be not only the compound layer of Fe-C-N system, and compared with embodiment, be the layer that erosion resistance is on duty mutually.
Fig. 4 represents for embodiment and comparative example 2, use contactless determinator (the fine surface-profile measuring instrument of ZetaInstruments Inc. pan focus PLUS optical profile type 3D), measure surface shape through about 100 μm long (nominal lengths) and the measurement result obtained.Figure is from the viewed curve in section side.It should be noted that, comparative example 2 be the value of specific surface area large, as the current salt Bath Nitriding Treatment product generally adopted the nitriding treatment concerning brake-shoe etc.Comparative example 2 is milder surface unevenness profile, and on the other hand, the ditch portion (recess) of the degree of depth more than 0.5 μm of embodiment is at least being that the high-density at more than 2 ~ 3 places exists in every nominal length 50 μm.In addition, the known concaveconvex shape being formed as the complexity in short interval with the large recess of difference highly and protuberance.As can be known from the above results, in an embodiment, the value of specific surface area becomes large, and bond area increases.And, also increase based on there is the ditch portion of multiple more than 0.5 μm in the short cycle and the anchoring effect realized.Thus, the surface shape that formation cementability and adaptation are very excellent.
Embodiment 2
Use SPFH590 material, implement adaptation evaluation test.As the nitridation treatment method of test film, under the condition of table 2, fluoridation is implemented for test film.That is, utilization nitrogen dilution and the NF of the 10 capacity % obtained
3gas implement the specified time fluoridize operation after, stop NF
3the supply of gas, implements the diffusing procedure of specified time.
For Embodiment B 2, utilize the diffusing procedure fluoridizing operation and 5 minutes that aforesaid method is implemented 2.5 minutes, then implement the diffusing procedure fluoridizing operation and 10 minutes of 2.5 minutes further.
For Embodiment C 2, utilize the diffusing procedure fluoridizing operation and 2 minutes that aforesaid method is implemented 1 minute, then implement the diffusing procedure fluoridizing operation and 3 minutes of 1 minute, and then implement the diffusing procedure fluoridizing operation and 5 minutes of 1 minute.
Then, by first for these test films homogeneous heating to 400 DEG C, at the NH of 50 capacity %
3the N of gas and 50 capacity %
2carry out the reduction treatment of fluorinated layer in gas atmosphere, be warming up to 580 DEG C with 3 DEG C/min simultaneously.Then, at 580 DEG C, in stove, supply the NH of 100 capacity %
3gas 30 minutes, implements nitriding treatment, and cools.In the lump table 2 is shown in for the fluorinated layer thickness after the fluoridation of each test film and surface fluorine concentration.
Table 2
From the result of B2, the C2 in table 2, when be divided into implement fluoridation for several times, can suppress surface Funing tablet rising while, form thick fluorinated layer.
Above-mentioned method is utilized to carry out nitriding treatment to these test films.Now, as Embodiment C 2-2, after the nitrogenize of C2 terminates, cool in containing the nitrogen of aerobic 0.1 capacity %, produce the test film of the oxide skin being formed with mean thickness about 1.0 μm.In addition, as Embodiment C 2-3, produce and use the ceramic particle of median size about 60 μm to project the surface of the cooled test film of C2-2 under the pressure of 0.2 ~ 0.3MPa and the test film that obtains.
For the test film after processing under the condition of embodiment and comparative example, attach each other with the surface of caking agent by 2 pieces of test films respectively, implement the salt spray testing of the use 5%NaCl aqueous solution of 1000 hours, then implement above-mentioned bonding strength test.The results are shown in table 3.
It should be noted that, for the test film (salt Bath Nitriding Treatment product) of the comparative example 2 in embodiment 1, also implement same bonding strength test, be shown in Table 3 in the lump.
Table 3
As shown in Table 3, the thickness of the second compound layer utilizing method of the present invention to be formed brings very large impact to bonding strength.And, known by making its thickness optimization, and can high-adhesive-strength be obtained.That is, when making its thickness significantly lower than 1 μm, the raising of bonding strength cannot be expected, otherwise, when blocked up, also demonstrate bonding strength and reduce.
As shown in Table 2, the Funing tablet of thickness on fluorinated layer thickness, this fluorinated layer of the second compound layer brings very large impact.For a of the too small comparative example 1 of the thickness of the second compound layer, low with the adaptation of caking agent, therefore, easily promote to get rusty, its result, bonding strength is low.On the other hand, for the b of the blocked up comparative example 1 of the second compound layer thickness, especially can see that the adaptation of the nitride compound layer of male portion and bottom reduces.This can think following cause: the ratio gasified when reducing to fluorinated layer is many, and therefore the intensity of jog reduces, and then also reduces with the adaptation of caking agent, and therefore rust area also increases, result, and bonding strength reduces.
On the other hand, for embodiment, known compared with comparative example 2, rust area, bonding strength are all excellent.Particularly utilize not only arrange fluoridize operation and diffusing procedure and the method also they alternately repeated to implement this situation of fluoridation, more excellent result can be reached.Can judge: do not make the Funing tablet on surface exceedingly increase and method that fluorine is soaked into by application, thus erosion resistance and the more excellent upper layer of cementability can be formed.
In addition, from the result of Embodiment C 2-2 and C2-3, for the situation that addition of oxidation operation, especially erosion resistance is improved compared with C2.Therefore, can think and the reduction extremely not easily causing the bonding strength caused because of the generation of rust all demonstrate the value of high-adhesive-strength.
Fig. 5 illustrates the surperficial SEM photo of Embodiment C 2-2 and C2-3.Only applying the more weak oxide treatment not making surface shape seriously destroy, just the through defect existed in nitride compound layer is carried out sealing of hole, is therefore the test film demonstrating high corrosion resistance.In addition, carry out particulate shot peening, the part that unwanted, particle, nitride, oxide compound, the oxynitride etc. that are attached to surface are formed in the mode covered on convex-concave surface is not removed with making the concaveconvex shape havoc on surface.Thus, result demonstrates, and the possibility improving bonding strength under the state maintaining erosion resistance is high.Thus, result demonstrates, and additional, the additional of particulate shot peening operation that carry out treatment process are preferred embodiments.
According to above result, the surface treatment method of steel of the present invention less expensive is treated to main surface treatment method with gas nitriding, can form the high buckle layer of cementability, and can form the high nitride compound layer of erosion resistance at steel surface.Thus, the steel after surface treatment are carried out for by surface treatment method of the present invention, such as, cementability when can form adhesive friction material is high and extremely not easily produce the upper layer of rust, thus, through also not easily causing the problems such as the stripping of friction materials for a long time, that is, can be used as the component of excellent in te pins of durability.
Utilizability in industry
Steel work obtained by manufacturing method according to the invention has cementability and the equal excellent upper layer of erosion resistance both sides on surface, such as, can be used as the backing metal etc. of the brake facing, brake-shoe, clutch plate etc. of excellent in te pins of durability well.It should be noted that, the scope of application of the present invention is not limited to this.If for needing adhesiveproperties in the environment needing erosion resistance, then can play excellent performance in a variety of applications where.
Nomenclature
1 second compound layer
2 first compound layers
3 nitrogen diffused layers
4 mother metals
Claims (11)
1. a steel work, is characterized in that,
Be formed with nitride compound layer and nitrogen diffused layer on the top layer of the mother metal as steel, described steel work uses as the backing metal of friction member, wherein,
Described nitride compound layer comprises: the first compound layer formed in nitrogen diffused layer side and the second compound layer formed in the face side of described first compound layer,
Described first compound layer is with Fe
3n is the layer of the epsilon structure of main body,
Described second compound layer be nitrogen concentration in mass % higher than the first compound layer and surface nitrogen concentration be more than 12 quality %, comprise Fe
2the layer of the ζ structure of N,
Be formed with concave-convex surface on the surface of the layer of described ζ structure, this concave-convex surface has the interrupted ditch portion of multiple prescribed depth, and described prescribed depth is more than 0.5 μm and with the thickness of the layer of described ζ structure for the upper limit.
2. steel work according to claim 1, wherein,
The concave-convex surface of described second compound layer is in the nominal length of at least every 50 μm to be the recess that the high-density at more than 3 places has the degree of depth more than 0.5 μm.
3. steel work according to claim 1 and 2, wherein,
The thickness of described second compound layer is more than 0.7 μm.
4. steel work according to claim 1 and 2, wherein,
The thickness of described first compound layer is more than 5 μm.
5. steel work according to claim 1 and 2, wherein,
The real surface of the per unit area on surface amasss than the value for being greater than 1.8.
6. steel work according to claim 1 and 2, wherein,
Second compound layer is formed with the zone of oxidation based on ferriferous oxide of thickness less than 3 μm as outermost layer.
7. steel work according to claim 1 and 2, wherein,
The through defect existed in the second compound layer is by the oxide compound sealing of hole based on ferriferous oxide.
8. a manufacture method for steel work, is characterized in that,
After the fluoridation making fluorine spread is implemented to the surface of steel, implement to make nitrogen carry out the gas nitriding process of spreading, thus form nitride compound layer and nitrogen diffused layer on the top layer of mother metal, wherein,
Described fluoridation comprises: while import fluorine source gas in process stove, while fluorine and steel are reacted fluoridize operation, keep heating with under the state of supply stopping fluorine source gas, make the fluorine being soaked in described steel surface at least diffuse to the diffusing procedure of the degree of depth of more than 1 μm
In described gas nitriding process, utilize the gas atmosphere of not carbonaceous sources to carry out reduction and the gasification of the fluorine composition after described diffusion, and nitrogen is spread soak into form nitride compound layer and nitrogen diffused layer.
9. the manufacture method of steel work according to claim 8, wherein,
Operation will be fluoridized and diffusing procedure repeats more than 2 times in described fluoridation.
10. the manufacture method of steel work according to claim 8 or claim 9, wherein,
After the described gas nitriding process of enforcement,
Form the oxide skin based on ferric oxide of thickness less than 3 μm on surface, will the through defect sealing of hole of nitride compound layer be present in thus.
The manufacture method of 11. steel work according to claim 8 or claim 9, wherein, in enforcement institute
After stating gas nitriding process,
Implementing the particulate shot peening that median size is less than 100 μm, by covering the removing such as unwanted nitride, oxide compound, oxynitride of outmost surface, making the concave-convex surface of the degree of depth more than 0.5 μm expose thus.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011140054A JP5044712B1 (en) | 2011-06-24 | 2011-06-24 | Steel back metal for friction material and method for manufacturing steel product |
| JP2011-140054 | 2011-06-24 | ||
| PCT/JP2012/061166 WO2012176551A1 (en) | 2011-06-24 | 2012-04-19 | Steel product and manufacturing method therefor |
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| Publication Number | Publication Date |
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| CN103620081A CN103620081A (en) | 2014-03-05 |
| CN103620081B true CN103620081B (en) | 2016-04-06 |
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| CN201280031158.4A Active CN103620081B (en) | 2011-06-24 | 2012-04-19 | Steel work and manufacture method thereof |
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| US (1) | US20140102592A1 (en) |
| JP (1) | JP5044712B1 (en) |
| CN (1) | CN103620081B (en) |
| WO (1) | WO2012176551A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP6234803B2 (en) * | 2013-12-18 | 2017-11-22 | 曙ブレーキ工業株式会社 | Pressure plate, brake pad using the same, and manufacturing method thereof |
| DE102014008844A1 (en) * | 2014-06-14 | 2015-12-17 | Daimler Ag | Brake disc for a motor vehicle |
| JP6308041B2 (en) * | 2014-06-17 | 2018-04-11 | 株式会社ジェイテクト | Friction plate, friction plate manufacturing method and inspection method |
| JP6084996B2 (en) * | 2015-02-04 | 2017-02-22 | 株式会社不二機販 | Strengthening adhesion of low temperature ceramic coating |
| JP6487276B2 (en) * | 2015-06-01 | 2019-03-20 | 株式会社ジェイテクト | Manufacturing method of sliding member and manufacturing method of clutch plate |
| CN106868444A (en) * | 2017-03-29 | 2017-06-20 | 济南弘正科技有限公司 | A kind of clutch outer aggregate surface oxidation processing technique |
| CN107214305B (en) * | 2017-05-18 | 2019-11-15 | 烟台兴创汽车配件有限公司 | A kind of brake block |
| CN107328265A (en) * | 2017-07-31 | 2017-11-07 | 南京通用化工设备技术研究院 | A kind of high-voltage-resistant anti-corrosion condenser |
| JP7268983B2 (en) * | 2018-09-14 | 2023-05-08 | 三井化学株式会社 | Building materials and methods of manufacturing building materials |
| JP7258598B2 (en) * | 2019-02-27 | 2023-04-17 | 三井化学株式会社 | Bonded structures and metal members |
| JP6818207B1 (en) * | 2019-07-24 | 2021-01-20 | Ｒｔｍ 株式会社 | Surface treatment method for cooling holes in molds |
| CN113638021A (en) * | 2021-08-27 | 2021-11-12 | 济南金麒麟刹车系统有限公司 | Antirust method of brake pad and brake pad prepared by same |
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| US5417776A (en) * | 1991-07-17 | 1995-05-23 | Daidousanso Co., Ltd. | Hard austenitic stainless steel screw |
| CN102239273A (en) * | 2008-12-02 | 2011-11-09 | 住友金属工业株式会社 | Carbonitrided member and process for producing carbonitrided member |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPS6479362A (en) * | 1987-09-22 | 1989-03-24 | Isuzu Motors Ltd | Method and device for surface hardening |
| JPH05346129A (en) * | 1992-06-12 | 1993-12-27 | Nisshinbo Ind Inc | Disc brake pad |
| JP2002130409A (en) * | 2000-10-30 | 2002-05-09 | Koyo Seiko Co Ltd | Dry type continuously variable transmission |
| JP2011011032A (en) * | 2009-07-06 | 2011-01-20 | River Light:Kk | Method for manufacturing iron pan not requiring dry heating, hardly rusting, and excellent in heat distortion resistance |
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2011
- 2011-06-24 JP JP2011140054A patent/JP5044712B1/en active Active
-
2012
- 2012-04-19 CN CN201280031158.4A patent/CN103620081B/en active Active
- 2012-04-19 US US14/123,540 patent/US20140102592A1/en not_active Abandoned
- 2012-04-19 WO PCT/JP2012/061166 patent/WO2012176551A1/en active Application Filing
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5417776A (en) * | 1991-07-17 | 1995-05-23 | Daidousanso Co., Ltd. | Hard austenitic stainless steel screw |
| CN102239273A (en) * | 2008-12-02 | 2011-11-09 | 住友金属工业株式会社 | Carbonitrided member and process for producing carbonitrided member |
Also Published As
| Publication number | Publication date |
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| CN103620081A (en) | 2014-03-05 |
| WO2012176551A1 (en) | 2012-12-27 |
| JP2013007094A (en) | 2013-01-10 |
| JP5044712B1 (en) | 2012-10-10 |
| US20140102592A1 (en) | 2014-04-17 |
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