CN106756759B - Tough nitriding layer of a kind of ferrous alloy surface height and preparation method thereof - Google Patents
Tough nitriding layer of a kind of ferrous alloy surface height and preparation method thereof Download PDFInfo
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- CN106756759B CN106756759B CN201611102517.7A CN201611102517A CN106756759B CN 106756759 B CN106756759 B CN 106756759B CN 201611102517 A CN201611102517 A CN 201611102517A CN 106756759 B CN106756759 B CN 106756759B
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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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Abstract
The present invention relates to high tough nitriding layers in a kind of ferrous alloy surface and preparation method thereof, when preparation, after the surface of ferrous alloy sample is polished, is polished, it is packed into gas nitriding furnace, is passed through gaseous nitrogen source, carries out gas nitriding processing, by nitrogen potential control below the nitrogen gesture critical value that compound layer is formed, to gas nitriding after treatment, progress furnace is cold or oily cold, obtains the nitriding layer of no compound layer；Surface shot blasting strengthening processing is carried out to the nitriding layer of no compound layer obtained, obtains the high tough nitriding layer in ferrous alloy surface.Compared with prior art, the hardness of nitriding layer made from the method for the present invention can be with conventional gas nitriding compound layer hardness quite (even higher), and toughness is substantially better than compound layer, simultaneously, brittle flaking off defect when the method for the present invention can effectively overcome conventional gas nitriding part to be on active service under heavy duty, shear stress operating condition, widens the application range of gas nitriding technology.
Description
Technical field
The invention belongs to the process for modifying surface fields of metal material, are related to a kind of high tough nitriding layer in ferrous alloy surface
And preparation method thereof.
Background technique
Gas nitriding is one of the process for modifying surface being most widely used in industrial production, it can effectively improve steel
Hardness, wearability and corrosion resistance of material surface etc..Under normal conditions, it can be obtained in piece surface using gas nitriding technology
It obtains by outermost compound layer (ε-Fe2-3N+γ′-Fe4N-type nitride) and the compound nitriding of time surface layer nitrogen diffusion region composition it is modified
Layer.However, compound layer is usually because internal stress height causes toughness poor, especially in heavy load abrasion, shearing force and heat/power
It impacts and broken, peeling easily occurs under operating condition, show extremely short service life.For this purpose, being applied to the gas of above-mentioned special occasions
Nitriding part is before use, usually remove its surface compound layer, with the more excellent secondary surface layer diffusion of toughness and bearing capacity
It is directly on active service in area's (no compound nitriding layer).Although nitriding surface layer toughness can be improved in this method really, and reduces brittle flaking off wind
Danger, but the hardness (intensity) of this no compound nitriding surface layer (i.e. nitrogen diffusion layer) and conventional underloading wearability are substantially less than again and change
Close nitride layer.
Obviously, conventional gas nitridation process can not improve the intensity (hardness) and toughness on part surface layer simultaneously, i.e. gas seeps
The hardness on compound surface layer obtained by nitrogen is high, poor toughness, and without compound nitriding surface layer (diffusion skin) although good-toughness,
Hardness is low.Currently, there are the inversion relationship of hardness and toughness in traditional gas nitriding strengthening mechanism, gas nitriding technology into
There are still certain limitations with large-scale application for the development of one step.
A kind of high Strengthening and Toughening surface of metal material is disclosed application No. is the Chinese invention patent of 201310668391.X to change
Property method.This method is after metal material surface is polished, is polished, is cleaned and dries pretreatment, by pretreated material
Surface carries out laser peening processing, and then the surface by laser peening processing carries out magnetic field nitriding, and the surface after nitriding is carried out
Surface after magnetic-field quenching is being carried out low energy laser bead, finally by low energy laser bead by magnetic-field quenching again
Surface carries out magnetic-field quenching again, obtains the smooth tough surface of height.Compared with above-mentioned patent, it is an object of the invention to synthesis
Improve the toughness and tenacity of nitriding layer, but then has notable difference in terms of technological means and implementation.Different from above-mentioned comparison patent, originally
Inventive method pays close attention to the own advantages of controllable gas nitriding and shot peening technique and by its reasonable combination, i.e., first
The brittleness for controlling nitriding strengthening layer, then improves intensity, does not introduce surface brittleness in middle process, realize that final surface is strong
Toughening, technological operation is simple and controllability is strong.
Summary of the invention
It is seeped it is an object of the present invention to overcome the above-mentioned drawbacks of the prior art and provide one kind can integrate improvement
The intensity and toughness of nitrogen layer can effectively improve the high tough nitriding layer in ferrous alloy surface and its preparation of nitriding part service life
Method.
The purpose of the present invention can be achieved through the following technical solutions:
A kind of preparation method of the high tough nitriding layer in ferrous alloy surface, this method specifically includes the following steps:
Step (1): after the surface of ferrous alloy sample is polished, polished, it is packed into gas nitriding furnace, is passed through gaseous nitrogen
Source carries out gas nitriding processing, and nitrogen potential control is tied in the nitrogen gesture critical value that compound layer is formed hereinafter, handling to gas nitriding
Shu Hou, progress furnace is cold or oily cold, obtains the nitriding layer of no compound layer；
Step (2): surface shot blasting strengthening processing is carried out to step (1) nitriding layer obtained without compound layer, is obtained
The high tough nitriding layer in the ferrous alloy surface.
The condition of the processing of gas nitriding described in step (1) are as follows: controlled at 500~580 DEG C, the time of Nitrizing Treatment
For 5~20h.
Nitrogen potential control described in step (1) is 0.15-0.22.
Gaseous nitrogen source described in step (1) is ammonia.
In gas nitriding treatment process described in step (1), it can be stablized by adjusting ammonia decomposition and flow
Nitrogen gesture and controlled compound layer formed nitrogen gesture critical value below.
The condition of the processing of surface shot blasting strengthening described in step (2) are as follows: bullet diameter is 0.6~3mm, and shot peening strength is
0.10~0.40A, coverage rate are 100~300%.
The high tough nitriding layer in ferrous alloy surface being prepared using the above method, which is to become through surface plasticity
The gas nitriding layer without compound layer of shape processing.
The surface plastic deformation processing is that surface shot blasting strengthening is handled.
The surface carburization layer that the gas nitriding layer without compound layer is formed for no continuous nitride object.
In fact, gas nitriding is multiple after the technique that gas nitriding at present is combined with bead is concentrated mainly on pre- shot-peening
Technique is closed, mainly relying on bead is that workpiece surface introduces dislocation, provides the diffusion admittance of nitrogen-atoms, plays acceleration and seeps
The purpose of nitrogen.In view of the high brittleness of conventional gas nitriding compound layer, can not further be deformed after general gas flow nitriding
Processing, therefore the present invention proposes that choosing controllable gas nitriding is initial process, it is intended that the brittleness of its nitriding layer is controlled, is also subsequent
Shot blasting on surface deformation process provide necessary condition.
The method of the present invention can integrate the intensity and toughness for improving nitriding layer, especially overcome conventional gas under the conditions of heavy load abrasion
The brittle flaking off phenomenon on nitriding surface layer optimizes germinating and the propagation behavior of nitriding surface layer heat fatigue cracking, improves nitriding part
Service life, the application range of enlargement gas nitridation process.
Compared with prior art, the invention has the characteristics that:
1) in entire gas nitriding, inhibit the appearance of nitriding surface layer compound using controllable gas nitridation process, no
Nitriding surface brittleness is only controlled, also provides prerequisite for the surface deformation processing of next stage, which can get tool
Standby certain thickness toughness nitriding layer；
2) can be drawn under the premise of not losing hardened layer integral thickness in nitriding part surface layer using surface shot blasting strengthening processing
Enter dislocation and residual compressive stress etc., and then can the effective compensation first stage gained insufficient defect of nitriding layer hardness；
3) the method for the present invention has broken " hardness-toughness " inversion relationship caused by pure gas nitriding is strengthened, and can especially have
Effect overcomes the heavy load abrasion peeling phenomenon on conventional gas nitriding surface layer, optimizes germinating and the propagation behavior of thermal fatigue course crackle,
The preparation for the high tough modified layer in key components and parts surface provides technical basis simultaneously, and that widens gas nitriding technology applies model
It encloses；
It 4) can be with conventional gas nitriding compound layer hardness quite (very using the hardness on nitriding surface layer obtained by the method for the present invention
To higher), and toughness is substantially better than compound layer.
Detailed description of the invention
Fig. 1 is the cross section tissue pattern SEM figure that embodiment 1 prepares sample；
Fig. 2 is cross section tissue pattern SEM figure of the conventional gas nitriding compound layer after bead in embodiment 2；
Fig. 3 is the heavy load abrasion pattern SEM figure on the sample surface layer of the method for the present invention preparation in embodiment 2；
Fig. 4 is the heavy load abrasion pattern SEM figure on conventional gas nitriding compound surface layer in embodiment 2.
Specific embodiment
The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings.
Embodiment 1:
The conditioned processing post-processing of 13 steel of H is hung on after polishing, polishing, cleaning at 80 × 30 × 10mm thin plate sample
In homemade gas nitriding furnace, 550 DEG C are warming up to, in NH3For medium, nitrogen gesture is that 0.20 horizontal lower gas nitriding handles 10h, after
The N in furnace2It is quickly cooled down under protective condition.The bullet for then choosing 0.8mm diameter, in 0.15Amm intensity and 200% coverage rate
Surface shot blasting strengthening is carried out to the sample after Nitrizing Treatment under parameter.
Surface deformation nitriding layer tissue obtained by present invention process is smooth, and (see Fig. 1) occurs in no apparent crackle.
Embodiment 2:
The plaques that 38CrMoAl steel is processed into 70 × 30 × 12mm are placed in homemade gas nitriding furnace, in NH3
For medium, 530 DEG C of temperature, gas nitriding handles 20h under 0.22 and 2.0 nitrogen gesture levels, then in N2Fast quickly cooling under protective condition
But.Then choose 3mm diameter bullet, under 0.40Amm intensity and 300% coverage rate parameter to above two nitridation process at
Sample after reason carries out surface shot blasting strengthening, and discovery conventional gas nitriding layer (nitrogen gesture 2.0) layer occurs obviously after bead
Longitudinal crack, part along compound layer through cracking (see Fig. 2).
Using pin-disk-type friction abrasion tester, 30min, surface abrasion are worn under 300g load to two groups of samples
Varying topography is larger.Surface deformation nitriding layer obtained by the present embodiment is compared with the conventional gas nitriding layer tool prepared under 2.0 nitrogen gesture levels
Standby more excellent intensity and toughness are arranged in pairs or groups, and do not observe apparent abrasive wear under the higher wear working condition of normal load
Feature (see Fig. 3), and find apparent brittle flaking off phenomenon (see figure in the wear morphology of conventional gas nitriding compound layer
4), the polishing machine sample more of the invention for preparing is obviously poor, this is high with compound layer internal stress, brittleness is big, in top load item
It is easily broken closely related under part.
Embodiment 3:
The preparation method of the high tough nitriding layer in the present embodiment ferrous alloy surface, specifically includes the following steps:
Step (1): after the surface of ferrous alloy sample is polished, polished, it is packed into gas nitriding furnace, is passed through gaseous nitrogen
Source carries out gas nitriding processing, and nitrogen potential control is tied in the nitrogen gesture critical value that compound layer is formed hereinafter, handling to gas nitriding
Shu Hou, progress furnace is cold or oily cold, obtains the nitriding layer of no compound layer；
Step (2): surface shot blasting strengthening processing is carried out to step (1) nitriding layer obtained without compound layer, is obtained
The high tough nitriding layer in the ferrous alloy surface.
Wherein, the condition that gas nitriding is handled in step (1) are as follows: controlled at 500 DEG C, the time of Nitrizing Treatment is
20h.Nitrogen potential control is 0.15.Gaseous nitrogen source is ammonia.In gas nitriding treatment process, adjustable ammonia decomposition (85%
More than) and flow, it obtains stable nitrogen gesture and is controlled below the nitrogen gesture critical value that compound layer is formed
In step (2), surface shot blasting strengthening processing condition are as follows: bullet diameter be 0.6mm, shot peening strength 0.10Amm,
Coverage rate is 100%.
The high tough nitriding layer in ferrous alloy surface made from the present embodiment, which is to handle through surface plastic deformation
Gas nitriding layer without compound layer.Surface plastic deformation processing is that surface shot blasting strengthening is handled.The gas of no compound layer seeps
The surface carburization layer that nitrogen layer is formed for no continuous nitride object.
Embodiment 4:
The preparation method of the high tough nitriding layer in the present embodiment ferrous alloy surface, specifically includes the following steps:
Step (1): after the surface of ferrous alloy sample is polished, polished, it is packed into gas nitriding furnace, is passed through gaseous nitrogen
Source carries out gas nitriding processing, and nitrogen potential control is tied in the nitrogen gesture critical value that compound layer is formed hereinafter, handling to gas nitriding
Shu Hou, progress furnace is cold or oily cold, obtains the nitriding layer of no compound layer；
Step (2): surface shot blasting strengthening processing is carried out to step (1) nitriding layer obtained without compound layer, is obtained
The high tough nitriding layer in the ferrous alloy surface.
Wherein, the condition that gas nitriding is handled in step (1) are as follows: controlled at 580 DEG C, the time of Nitrizing Treatment is
5h.Nitrogen potential control is 0.22.Gaseous nitrogen source is ammonia.In gas nitriding treatment process, adjustable ammonia decomposition (85% with
On) and flow, it obtains stable nitrogen gesture and is controlled below the nitrogen gesture critical value that compound layer is formed
In step (2), the condition of surface shot blasting strengthening processing are as follows: bullet diameter is 3mm, and shot peening strength 0.40Amm covers
Lid rate is 300%.
The high tough nitriding layer in ferrous alloy surface made from the present embodiment, which is to handle through surface plastic deformation
Gas nitriding layer without compound layer.Surface plastic deformation processing is that surface shot blasting strengthening is handled.The gas of no compound layer seeps
The surface carburization layer that nitrogen layer is formed for no continuous nitride object.
Embodiment 5:
The preparation method of the high tough nitriding layer in the present embodiment ferrous alloy surface, specifically includes the following steps:
Step (1): after the surface of ferrous alloy sample is polished, polished, it is packed into gas nitriding furnace, is passed through gaseous nitrogen
Source carries out gas nitriding processing, and nitrogen potential control is tied in the nitrogen gesture critical value that compound layer is formed hereinafter, handling to gas nitriding
Shu Hou, progress furnace is cold or oily cold, obtains the nitriding layer of no compound layer；
Step (2): surface shot blasting strengthening processing is carried out to step (1) nitriding layer obtained without compound layer, is obtained
The high tough nitriding layer in the ferrous alloy surface.
Wherein, the condition that gas nitriding is handled in step (1) are as follows: controlled at 550 DEG C, the time of Nitrizing Treatment is
10h.Nitrogen potential control is 0.20.Gaseous nitrogen source is ammonia.In gas nitriding treatment process, adjustable ammonia decomposition (85%
More than) and flow, it obtains stable nitrogen gesture and is controlled below the nitrogen gesture critical value that compound layer is formed
In step (2), the condition of surface shot blasting strengthening processing are as follows: bullet diameter is 2mm, and shot peening strength 0.30Amm covers
Lid rate 200%.
The high tough nitriding layer in ferrous alloy surface made from the present embodiment, which is to handle through surface plastic deformation
Gas nitriding layer without compound layer.Surface plastic deformation processing is that surface shot blasting strengthening is handled.The gas of no compound layer seeps
The surface carburization layer that nitrogen layer is formed for no continuous nitride object.
The above description of the embodiments is intended to facilitate ordinary skill in the art to understand and use the invention.
Person skilled in the art obviously easily can make various modifications to these embodiments, and described herein general
Principle is applied in other embodiments without having to go through creative labor.Therefore, the present invention is not limited to the above embodiments, ability
Field technique personnel announcement according to the present invention, improvement and modification made without departing from the scope of the present invention all should be of the invention
Within protection scope.
Claims (7)
1. a kind of preparation method of the high tough nitriding layer in ferrous alloy surface, which is characterized in that this method specifically includes following step
It is rapid:
Step (1): after the surface of ferrous alloy sample is polished, polished, being packed into gas nitriding furnace, be passed through gaseous nitrogen source,
Gas nitriding processing is carried out, the nitrogen gesture critical value that nitrogen potential control is formed in compound layer is hereinafter, processing terminate to gas nitriding
Afterwards, it is cold or oily cold to carry out furnace, obtains the nitriding layer of no compound layer；
Step (2): surface shot blasting strengthening processing is carried out to step (1) nitriding layer obtained without compound layer, is obtained described
The high tough nitriding layer in ferrous alloy surface；
The condition of the processing of gas nitriding described in step (1) are as follows: controlled at 500~580 DEG C, the time of Nitrizing Treatment is 5
~20h；
Nitrogen potential control described in step (1) is 0.15-0.22.
2. a kind of preparation method of the high tough nitriding layer in ferrous alloy surface according to claim 1, which is characterized in that step
Suddenly gaseous nitrogen source described in (1) is ammonia.
3. a kind of preparation method of the high tough nitriding layer in ferrous alloy surface according to claim 1, which is characterized in that step
Suddenly the condition of the processing of surface shot blasting strengthening described in (2) are as follows: bullet diameter is 0.6~3mm, and shot peening strength is 0.10~0.40A
Mm, coverage rate are 100~300%.
4. using the high tough nitriding layer in ferrous alloy surface that the described in any item methods of claims 1 to 3 are prepared.
5. the high tough nitriding layer in ferrous alloy surface according to claim 4, which is characterized in that the nitriding layer is warp
The gas nitriding layer without compound layer of surface plastic deformation processing.
6. the high tough nitriding layer in ferrous alloy surface according to claim 4, which is characterized in that the surface plasticity becomes
Shape processing is that surface shot blasting strengthening is handled.
7. the high tough nitriding layer in ferrous alloy surface according to claim 4, which is characterized in that the no compound layer
The surface carburization layer that is formed for no continuous nitride object of gas nitriding layer.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2960421A (en) * | 1958-11-10 | 1960-11-15 | Nat Broach & Mach | Elimination of white layer in nitrided steel |
| CN102812148A (en) * | 2010-05-11 | 2012-12-05 | 新东工业株式会社 | A method for surface treatment of a die-casting die |
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2016
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2960421A (en) * | 1958-11-10 | 1960-11-15 | Nat Broach & Mach | Elimination of white layer in nitrided steel |
| CN102812148A (en) * | 2010-05-11 | 2012-12-05 | 新东工业株式会社 | A method for surface treatment of a die-casting die |
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