CN109207909A - A kind of metal connecting piece surface treatment method - Google Patents

A kind of metal connecting piece surface treatment method Download PDF

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Publication number
CN109207909A
CN109207909A CN201811150385.4A CN201811150385A CN109207909A CN 109207909 A CN109207909 A CN 109207909A CN 201811150385 A CN201811150385 A CN 201811150385A CN 109207909 A CN109207909 A CN 109207909A
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China
Prior art keywords
connecting piece
metal connecting
salt bath
salt
temperature
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CN201811150385.4A
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Chinese (zh)
Inventor
马浩鹏
杨茂伟
莫炯堂
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Dongguan Leidi 3d History Numerical Control Technology Co Ltd
Dongguan City Shileidi 3D Numerical Control Technology Co Ltd
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Dongguan Leidi 3d History Numerical Control Technology Co Ltd
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Priority to CN201811150385.4A priority Critical patent/CN109207909A/en
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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
    • 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
    • C23C8/40—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 liquids, e.g. salt baths, liquid suspensions
    • C23C8/42—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 liquids, e.g. salt baths, liquid suspensions only one element being applied
    • 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
    • C23C8/40—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 liquids, e.g. salt baths, liquid suspensions
    • C23C8/52—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 liquids, e.g. salt baths, liquid suspensions more than one element being applied in one step
    • C23C8/54—Carbo-nitriding
    • 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
    • C23C8/40—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 liquids, e.g. salt baths, liquid suspensions
    • C23C8/58—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 liquids, e.g. salt baths, liquid suspensions more than one element being applied in more than one step

Abstract

The present invention relates to a kind of metal connecting piece surface treatment methods, it pre-processed, preheated by the surface to metal connecting piece, salt bath processing, oxidation, cooling, a series of processing such as surface polishing, again surface oxidation and oiling, metal connecting piece deformation quantity can be made minimum, wearability, the corrosion stability on metal connecting piece surface can be increased substantially again simultaneously, reaching outside has higher hardness, and inside has the applications well prospect of preferable metal toughness.

Description

A kind of metal connecting piece surface treatment method
Technical field
The present invention relates to a kind of surface treatment method, in particular to a kind of metal connecting piece surface treatment method.
Background technique
Metal connecting piece surface inevitably results from corruption during various heat treatments, machining, transport It loses, with greasy dirt and impurity etc., generates gasification phenomenon, this is just surface-treated.
There are many kinds of Treatment of Metal Surface, can be divided at solvent cleaning, mechanical treatment and chemistry according to the difference of its characteristic Manage three categories；According to the metal surface of different degree of oxidation, different processing modes should be used；It such as can for relatively thin oxide layer Using solvent cleaning, mechanical treatment and chemical treatment, or chemical treatment is directlyed adopt, for the metal surface of severe oxidation, Since oxide layer is thicker, if directlying adopt solvent cleaning and chemical treatment, not only processing is not thorough, and can also be wasted a large amount of clear Lotion and chemical agent preferably first use mechanical treatment；Solvent cleaning is to the one kind for using solvent to clean metal surface Processing method, this method can effectively remove the greasy dirt, impurity and oxide layer of workpiece surface, clean workpiece surface；Through Metal surface after solvent cleaning has high activity, it is easier to by the pollution of dust, moisture, so treated workpiece is also It the surface treatment such as sprayed, sprayed, improving the resistance to corrosion of workpiece.
But for metal connection parts (such as nut, bearing, valve body etc.) due to usually undertaking connection in a device Effect, therefore the reliability of connecting component is directly related to the quality of product, if connecting component is leaked in hydraulic system, is pulled out It is de-, efficiency can be caused to reduce, oil temperature increases, and executing agency is unstable, and pollution environment etc. directly affects the normal use of equipment； The defects of generally existing reliability of connecting component is low at present, easy leakage, is badly in need of undergoing technological transformation, at the surface of connecting component Reason technology carries out reasonable heat treatment process.
Summary of the invention
Since metal connecting piece is frequently necessary to cooperate with to connecting pipe, the outer diameter of junction is big compared with tube outer diameter, therefore Junction can more generate collision and friction relative to pipe fitting outer wall；Since connector needs and pipe fitting or other assembling fittings The close connection to pipe fitting is realized in cooperation, enables the frictional force between contact surface or screw pair to prevent connector from loosening, and can The vibration that pipe fitting is generated when conveying material is resisted, connector is thus needed to have certain metal toughness namely connector Needing to reach outside has higher hardness, and inside has preferable metal toughness.
Metal connects components usually small, thin, generally bulk heat treatmet, no longer machining after heat treatment；Due to work It is larger to be required local deformation, port requirements hardness is high, can shrink and there is not allowed that local bursting crack；Therefore, the table of such demand There are contradictions for demand between surface hardness, the thickness of permeable formation and connector overall flexibility, and the table of common stainless steel material Face hardening process is also immature, and the outside of connector has higher hardness, and there is the property of preferable metal toughness to need for inside It acquires and guarantees less than good.
A kind of metal connecting piece surface treatment method proposed the purpose of the present invention is to solve background technique, not only Deformation is small after enabling to the heat treatment efficiency height of metal connecting piece, handling, and has broad application prospects.
Inventor sums up following technique after research and testing to be surface-treated to metal connecting piece:
A kind of metal connecting piece surface treatment method, which is characterized in that in turn include the following steps:
1) surface preparation: metal connecting piece is before entering salt bath furnace, to the dirt, iron rust and oil on metal connecting piece surface Rouge is cleaned, and after cleaning, metal connecting piece is dried；
2) it preheats: the metal connecting piece after drying being placed in air furnace and is preheated, control preheating temperature 350~400 DEG C, 20~40min of preheating time；
3) nitrocarburizing salt bath is handled: the metal connecting piece after preheating being placed in nitrocarburizing salt bath furnace and is carried out at nitrocarburizing Reason periodically adds into nitrocarburizing salt bath furnace in process of production when the cyanate radical decline of salt bath in nitrocarburizing salt bath furnace Salt is adjusted, so that the cyanate concentration in salt bath is maintained between 36~40%, nitrocarburizing salt temperature is controlled 540~580 DEG C, 30~180min of time；
4) oxidation salt bath processing: the metal connecting piece after preheating is placed in oxidation salt bath furnace and carries out oxidation processes, aoxidizes salt bath Temperature control is at 350~400 DEG C, 15~30min of salt bath time；
5) cooling treatment: by aoxidize salt bath after metal connecting piece be placed in work rest carry out at room temperature it is air-cooled；
6) surface polishing treatment: the metal connecting piece after oxidation salt bath is processed by shot blasting by polishing machine；
7) metal connecting piece after polishing: being placed in oxidation salt bath furnace again and carries out oxidation processes by surface oxidation treatment again, Salt temperature control is aoxidized between 380~420 DEG C of temperature, 10~30min of time；
8) oiling: metal connecting piece being placed in hot engine oil and impregnates 20min, to seal oxide layer hole.
It is further limited as of the invention, in step 1), surface preparation mode is specially to use 80~90 DEG C Hot water or aqueous solution containing 1.5~3% sodium carbonate clean the dirt, iron rust and grease on metal connecting piece surface, clean Afterwards, metal connecting piece is dried by the way of spontaneously drying, compressed air dries up or 100~150 DEG C of drying.
As further restriction of the invention, the processing of nitrocarburizing salt bath uses base salt in step 3), wherein containing CNO- 40~45%, salt is adjusted by being added, adjusts CNO-Concentration is between 36~40%；Nitrocarburizing salt bath furnace uses external-heat crucible Smelting furnace, power 6KW, temperature control precision ± 5 DEG C, using Continuous aeration, ventilatory capacity is 7~9L/min, to reduce CN-Concentration, Improve CNO-Concentration reinforces the stability and mobility of salt, the temperature of saline solution in uniform furnace.
It is limited as of the invention further, the control of nitrocarburizing salt temperature is at 560 DEG C in step 3), the time 120min。
It is limited as of the invention further, the control of oxidation salt temperature is at 360 DEG C in step 4), the salt bath time 20min。
As further restriction of the invention, the oxidation salt temperature control of surface oxidation treatment exists again in step 7) Between 400 ± 5 DEG C of temperature, time 20min.
The beneficial effects of the present invention are:
1, preheating is carried out after pre-processing can dry the moisture on metal connecting piece surface, reenter after so that cold metal connecting piece is heated up Salt bath furnace enters salt bath temperature after salt bath furnace causes salt bath to sputter and prevents cold metal connecting piece from entering furnace with water to prevent metal connecting piece Degree decline is excessive；Preheating also has certain effect to the deformation for reducing metal connecting piece and the appearance for obtaining uniform color simultaneously.
2, the heat treatment process can make metal connecting piece deformation quantity minimum, while can increase substantially metal connection again Wearability, the corrosion stability on part surface, existing gas soft nitriding and glow discharge nitriding, which are substantially all, can use the Quench-Polish-Quench technology skill Art replaces, and can greatly improve the wearability and corrosion stability of metal connecting piece, and corrosion stability can reach the level of plating, Its wearability than blackening process be higher by hundred times, seawater corrosion prevention test life than blackening process part improve tens times.
3, after metal connecting piece immerses salt bath, cyanate radical decomposes N, C atom generated can be in the dot matrix gap in Fe atom In be diffused, with the raising of surface atom concentration, finally from workpiece surface to the concentration gradient for being centrally formed N, C, formed The diffusion layer organization of compound layer and diffusion layer composition；Therefore, the diffusion layer organization of treated metal connecting piece consists of three layers: outer Table is oxide layer, and it is inwardly diffusion layer that centre, which is chemical combination layer,；Mostly important with compound layer in diffusion layer organization, it is that raising is resistance to The most important part of mill property, while its corrosion stability is also fine；The main function of oxide layer be constituted together with chemical combination layer it is fabulous Resist layer, simultaneous oxidation layer is in porous state, can store lubricating fluid, reduces friction, and to improving, wearability is advantageous, simultaneously There are also the effects of aesthetic appeal；Diffusion layer main function is the fatigue strength for improving workpiece, the metal connecting piece thin, thin to increase Integral strength and elasticity also play the role of it is very big.
Detailed description of the invention
Fig. 1 is the metallographic structure figure under the different temperatures of metal connecting piece surface treatment method proposed by the present invention.
Specific embodiment
It is next combined with specific embodiments below that the present invention is further described.
Embodiment one
A kind of metal connecting piece surface treatment method, in turn includes the following steps:
1) surface preparation: metal connecting piece using 80~90 DEG C of hot water or contains 1.5~3% carbonic acid before entering salt bath furnace The aqueous solution of sodium cleans the dirt, iron rust and grease on metal connecting piece surface, after cleaning, using natural drying, pressure Metal connecting piece is dried in contracting air blow drying or the mode of 100~150 DEG C of drying；
2) it preheats: the metal connecting piece after drying being placed in air furnace and is preheated, control preheating temperature 350~400 DEG C, 20~40min of preheating time；
The main function of preheating is the moisture for drying metal connecting piece surface, reenters salt bath after so that cold metal connecting piece is heated up Furnace enters after salt bath furnace causes salt bath to sputter and prevents cold metal connecting piece from entering furnace under salt temperature to prevent metal connecting piece with water Drop is excessive；Preheating also has certain effect to the deformation for reducing metal connecting piece and the appearance for obtaining uniform color simultaneously.
3) nitrocarburizing salt bath is handled: the metal connecting piece after preheating being placed in nitrocarburizing salt bath furnace progress nitrogen carbon and is total to Infiltration processing, in process of production when the cyanate radical decline of salt bath in nitrocarburizing salt bath furnace, periodically to nitrocarburizing salt bath furnace In plus adjustment salt so that the cyanate concentration in salt bath is maintained between 36~40%, nitrocarburizing salt temperature is controlled 540 DEG C, 30~180min of time；
Nitrocarburizing salt bath processing effect be by the decomposition of cyanate radical in bath salt and generate active nitrogen, carbon atom penetrate into metal Connector forms wearability and the very high compound layer of corrosion stability and fatigue proof diffusion layer on metal connecting piece surface.
Base salt: main component is urea, sodium carbonate and potassium carbonate, additionally incorporates suitable potassium chloride or potassium hydroxide.Base Salt forms the cyanate radical (CNO of high-content after melting in nitrocarburizing salt bath furnace-), after being passed through air stirring, cyanate is direct It decomposes or is oxidized, generate activity N, C atom, [N], [C] are the essential elements of carbo-nitriding.
Adjust salt: in process of production when the cyanate radical decline of salt bath in nitrocarburizing salt bath furnace, periodically to nitriding furnace Add adjustment salt, so that the cyanic acid radical content in salt bath rises within the scope of set quota.The main component of adjustment salt is to have Machine condensation product, can be by CO3It is changed into CNO-.Its expression formula are as follows: a CO3+b Z1=x CNO-+ZH20。
4) oxidation salt bath processing: the metal connecting piece after preheating is placed in oxidation salt bath furnace and carries out oxidation processes, oxidation Salt temperature controls 15~30min of salt bath time between 350~400 DEG C；
The effect of oxidation salt bath processing -- it is the cyanogen root that thorough decomposing metal connector is brought out from nitrocarburizing salt bath furnace, reaches Environmental requirement；Second is that forming black oxide film on metal connecting piece surface, increase the wearability of anti-corrosion ability and metal connecting piece.
Saline oxide: saline oxide is added in oxidation furnace after fusing at the initial stage started to process and carries out at oxidation salt bath Reason continues to be added saline oxide into oxidation salt bath furnace when the decline of salt bath face is more to increase salt bath face.
5) cooling treatment: by aoxidize salt bath after metal connecting piece be placed in work rest carry out at room temperature it is air-cooled；
Cooling effect is the infiltration layer even compact for the metal connecting piece that makes that treated and increases diffusion layer depth, while being decomposed viscous The CN being attached on metal connecting piece surface-。
6) surface polishing treatment: the metal connecting piece after oxidation salt bath is processed by shot blasting by polishing machine；
The effect of surface polishing treatment is removal metal connecting piece part convex surfaces, makes metal connecting piece surface after secondary oxidation Oxidation film generate tensile stress a possibility that reduce, improve the corrosion resistance of metal connecting piece.
7) surface oxidation treatment again: the metal connecting piece after polishing is placed in oxidation salt bath furnace again and is carried out at oxidation Reason, oxidation salt temperature control is between 380~420 DEG C of temperature, 10~30min of time；
The effect of surface oxidation treatment is to supplement oxygen content to the surface layer of the metal connecting piece after polishing again, is repaired due to polishing The oxidation film being destroyed.
8) oiling: metal connecting piece being placed in hot engine oil and impregnates 20min, to seal oxide layer hole.
Wherein, nitrocarburizing salt bath processing uses base salt, adjusts salt by being added, adjusts CNO-Concentration 36~40% it Between；Nitrocarburizing salt bath furnace uses external-heat crucible smelting furnace, power 6KW, and 5 DEG C of temperature control precision soil is led to using Continuous aeration Tolerance is 7-9L/min, to reduce CN-, improve CNO-, reinforce the stability and mobility of salt, the temperature of saline solution in uniform furnace.
Embodiment two
The processing of step 3) nitrocarburizing salt bath: the metal connecting piece after preheating is placed in nitrocarburizing salt bath furnace progress nitrogen carbon and is total to Infiltration processing, in process of production when the cyanate radical decline of salt bath in nitrocarburizing salt bath furnace, periodically to nitrocarburizing salt bath furnace In plus adjustment salt so that the cyanate concentration in salt bath is maintained between 36~40%, nitrocarburizing salt temperature is controlled 560 DEG C, 30~180min of time.
Embodiment three
The processing of step 3) nitrocarburizing salt bath: the metal connecting piece after preheating is placed in nitrocarburizing salt bath furnace progress nitrogen carbon and is total to Infiltration processing, in process of production when the cyanate radical decline of salt bath in nitrocarburizing salt bath furnace, periodically to nitrocarburizing salt bath furnace In plus adjustment salt so that the cyanate concentration in salt bath is maintained between 36~40%, nitrocarburizing salt temperature is controlled 580 DEG C, 30~180min of time.
Referring to Fig. 1, by the metallographic structure figure of comparative example one, two, three, as permeation 120min, discovery metal connects Under the different temperatures of fitting surface treatment method (540 DEG C, 560 DEG C, 580 DEG C) with the raising of permeation temperature, chemical combination in infiltration layer The variation tendency of layer depth is as follows: when temperature is increased to 560 DEG C from 540 DEG C of degree, the depth of chemical combination layer is gradually increased, but works as temperature Continue after being increased to 580 DEG C, the depth of chemical combination layer is declined instead, and weaker zone thickness increases obviously；So permeation temperature Degree is that effect is best at 560 DEG C.
Therefore, the control of nitrocarburizing salt temperature is at 560 DEG C in the step 3) as a preferred technical solution, the time 120min。
Salt temperature control is aoxidized in step 4) at 360 DEG C, salt bath time 20min；In step 7) again at surface oxidation The oxidation salt temperature of reason controls the time 20min between 400 ± 5 DEG C of temperature.
The heat treatment process can make metal connecting piece deformation quantity minimum, while can increase substantially metal connecting piece again Wearability, the corrosion stability on surface, existing gas soft nitriding and glow discharge nitriding, which are substantially all, can use the Quench-Polish-Quench technology technology It replacing, and the wearability and corrosion stability of metal connecting piece can be greatly improved, corrosion stability can reach the level of plating, Wearability than blackening process be higher by hundred times, seawater corrosion prevention test life than blackening process part improve tens times.
In actual use, for general metal connecting piece, as long as being generally easy to reach according to the technique that enterprise provides It is required that workpiece infiltration layer thickness 0.1mm or more, infiltration layer maximum hardness is greater than HV900, reaches the requirement of wearability and corrosion stability；And it is thin Wall part, and require to keep sufficiently ductile, 0.03~0 06mm of workpiece infiltration layer thickness is suitable, and nitrided layer hardness also wants smaller, but is open Hardness, which will reach, can cut stainless steel tube, therefore nitrided layer hardness HV700-900 is appropriate；So just there is its uniqueness in technique Requirement, must strictly regulate in operation.
After metal connecting piece immerses salt bath, cyanate radical decomposes N, C atom generated can be in the dot matrix gap in Fe atom It is diffused, with the raising of surface atom concentration, finally from workpiece surface to the concentration gradient for being centrally formed N, C, formationization Close the diffusion layer organization of nitride layer and diffusion layer composition；Therefore, the diffusion layer organization of treated metal connecting piece consists of three layers: appearance For oxide layer, it is inwardly diffusion layer that centre, which is chemical combination layer,；Mostly important with compound layer in diffusion layer organization, it is that raising is wear-resisting The most important part of property, while its corrosion stability is also fine；The main function of oxide layer be constituted together with chemical combination layer it is fabulous Resist layer, simultaneous oxidation layer are in porous state, can store lubricating fluid, reduce friction, and to improving, wearability is advantageous, simultaneously also There is aesthetic appeal；Diffusion layer main function is the fatigue strength for improving workpiece, the metal connecting piece thin, thin to increase Integral strength and elasticity also play the role of very big.
The considerations of quality layer factor and control mode: the metal connecting piece quality of salt bath processing depends primarily on infiltration Whether layer reaches technical requirements, and the key of technique is the needs that various parameters guarantee infiltration layer, and determines that the principal element of infiltration layer is Nitrocarburizing, the temperature for aoxidizing salt bath, nitrocarburizing, the time for aoxidizing salt bath, cyanic acid radical content in nitrocarburizing salt bath and Four factors of basis material.
First, the control of temperature: temperature mainly determines according to the type of basis material, secondary consideration metal connecting piece Intensity requirement；Temperature is too low, cannot form the infiltration layer of enough depth；Temperature is too high, and weaker zone is serious, and temperature is more than tempering temperature Degree can then reduce the hardness of matrix；Through testing, it is appropriate salt temperature that the metal connecting piece of stainless steel, which uses 560 DEG C,.
Second, the control of time: the length of time depends primarily on the type of metal connecting piece and metal connecting piece uses Depending on condition；Time is too short, cannot form the infiltration layer of enough depth, and overlong time is then loose serious；Through testing, stainless steel metal The soaking time of connector is 120min.
Third, CNO-The control of concentration: processing is to improve the workpiece based on wearability, CNO-It should be 33~36%；Processing with CNO when improving and alleviate friction, anti scuffing, based on resistance to seizure energy, and having wear-resisting, anti-fatigue performance the workpiece of raising concurrently-It should be 36~40%；When the comprehensive performances such as friction, wear-resisting, antifatigue workpiece of equal importance is alleviated in processing, CNO-It should be 34~38%；Through Experiment, for the metal connecting piece of stainless steel, CNO-Content 36~38%, tough performance reach requirement.
Depth of penetration, surface hardness, inner hardness test are carried out to stainless metal connecting pieces, stainless steel metal is connected The caliber of part is squeezed by hydraulic press to 1/2 diameter, observes whether appearance cracks, and measures deformation situation, and the following table 1 gives three kinds The technological parameter and testing result of specification stainless metal connecting pieces.
The comparison of 1 stainless metal connecting pieces nitrocarburizing salt bath testing result of table
As it can be seen that depth of penetration 0.055mm or so is appropriate, maximum is no more than 0.7mm, and surface hardness 600-800HV is appropriate, most Good 700HV or more；It is confirmed again through test of many times afterwards, bore is small, and the small stainless metal connecting pieces of wall thickness dimension should make its infiltration layer It is slightly shallow, and guarantee surface hardness HV650 or more, then CNO when nitrocarburizing salt bath is handled-It is advisable for 36%；Bore is big, wall thickness ruler Very little big stainless metal connecting pieces, can make its infiltration layer slightly thick, mesh guarantee surface hardness HV700 or more, at nitrocarburizing salt bath CNO when reason-It is 38%；Open surfaces hardness was not only guaranteed in this way but also had kept whole hardness, and avoided surface porosity, peeling, had reached The hardness and internal toughness best match of the opening of stainless metal connecting pieces.
The present invention is pre-processed by the surface to metal connecting piece, is preheated, salt bath processing, aoxidized, cooling, surface is thrown A series of processing such as light, again surface oxidation and oiling, can make metal connecting piece deformation quantity minimum, while again can be significantly Wearability, the corrosion stability for improving metal connecting piece surface, reaching outside has higher hardness, and inside has preferable metal toughness Applications well prospect.
The foregoing is only a preferred embodiment of the present invention, but scope of protection of the present invention is not limited thereto, Anyone skilled in the art in the technical scope disclosed by the present invention, according to the technique and scheme of the present invention and its Inventive concept is subject to equivalent substitution or change, should be covered by the protection scope of the present invention.

Claims (6)

1. a kind of metal connecting piece surface treatment method, which is characterized in that in turn include the following steps:
1) surface preparation: metal connecting piece is before entering salt bath furnace, to the dirt, iron rust and oil on metal connecting piece surface Rouge is cleaned, and after cleaning, metal connecting piece is dried；
2) it preheats: the metal connecting piece after drying being placed in air furnace and is preheated, control preheating temperature 350~400 DEG C, 20~40min of preheating time；
3) nitrocarburizing salt bath is handled: the metal connecting piece after preheating being placed in nitrocarburizing salt bath furnace and is carried out at nitrocarburizing Reason periodically adds into nitrocarburizing salt bath furnace in process of production when the cyanate radical decline of salt bath in nitrocarburizing salt bath furnace Salt is adjusted, so that the cyanate concentration in salt bath is maintained between 36~40%, nitrocarburizing salt temperature is controlled 540~580 DEG C, 30~180min of time；
4) oxidation salt bath processing: the metal connecting piece after preheating is placed in oxidation salt bath furnace and carries out oxidation processes, aoxidizes salt bath Temperature control is at 350~400 DEG C, 15~30min of salt bath time；
5) cooling treatment: by aoxidize salt bath after metal connecting piece be placed in work rest carry out at room temperature it is air-cooled；
6) surface polishing treatment: the metal connecting piece after oxidation salt bath is processed by shot blasting by polishing machine；
7) metal connecting piece after polishing: being placed in oxidation salt bath furnace again and carries out oxidation processes by surface oxidation treatment again, Salt temperature control is aoxidized between 380~420 DEG C of temperature, 10~30min of time；
8) oiling: metal connecting piece being placed in hot engine oil and impregnates 20min, to seal oxide layer hole.
2. a kind of metal connecting piece surface treatment method according to claim 1, it is characterised in that: in the step 1), Surface preparation mode is specially the hot water for using 80~90 DEG C or the aqueous solution containing 1.5~3% sodium carbonate to metal connecting piece table Dirt, iron rust and the grease in face are cleaned, after cleaning, using natural drying, compressed air drying or 100~150 DEG C Metal connecting piece is dried in the mode of drying.
3. a kind of metal connecting piece surface treatment method according to claim 1, it is characterised in that: nitrogen in the step 3) The processing of carbon co-diffused salt bath uses base salt, adjusts salt by being added, adjusts CNO-Concentration is between 36~40%；Nitrocarburizing salt bath Furnace uses external-heat crucible smelting furnace, and power 6KW, temperature control precision ± 5 DEG C, using Continuous aeration, ventilatory capacity is 7~9L/ Min, to reduce CN-Concentration improves CNO-Concentration reinforces the stability and mobility of salt, the temperature of saline solution in uniform furnace.
4. a kind of metal connecting piece surface treatment method according to claim 1, it is characterised in that: nitrogen in the step 3) The control of carbon co-diffused salt bath temperature is at 560 DEG C, time 120min.
5. a kind of metal connecting piece surface treatment method according to claim 4, it is characterised in that: oxygen in the step 4) The control of salt dissolving bath temperature is at 360 DEG C, time 20min.
6. a kind of metal connecting piece surface treatment method according to claim 5, it is characterised in that: in the step 7) again The oxidation salt temperature of subsurface oxidation processes controls the time 20min between 400 ± 5 DEG C of temperature.
CN201811150385.4A 2018-09-29 2018-09-29 A kind of metal connecting piece surface treatment method Withdrawn CN109207909A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116065118A (en) * 2023-02-23 2023-05-05 浙江神秀新材料科技有限公司 Method for oxygen permeation of titanium alloy ions

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116065118A (en) * 2023-02-23 2023-05-05 浙江神秀新材料科技有限公司 Method for oxygen permeation of titanium alloy ions
CN116065118B (en) * 2023-02-23 2024-02-13 浙江神秀新材料科技有限公司 Method for oxygen permeation of titanium alloy ions

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