CN109778108A - A kind of Fe-Ni-Cr system high temperature alloy nitriding method - Google Patents
A kind of Fe-Ni-Cr system high temperature alloy nitriding method Download PDFInfo
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Abstract
A kind of Fe-Ni-Cr system high temperature alloy nitriding method, include: S1, nitriding pre-treatment is carried out to Fe-Ni-Cr system high temperature alloy, the process of nitriding pre-treatment include 1000 DEG C at a temperature of carry out solution treatment, it is cooling in such a way that oil is cold, then ageing treatment is carried out in two times, and the temperature of a timeliness is 850 DEG C, and furnace cooling is to 700 DEG C after keeping the temperature 3h-5h, it carries out secondary ageing at 700 DEG C again, keeps the temperature air-cooled after 16h；S2, the Fe-Ni-Cr system high temperature alloy Jing Guo nitriding pre-treatment is processed into sample and to outer surface blast；S3, manufactured sample is subjected to two-step method nitriding under nitrogen containing atmosphere, the temperature and resolution ratio of first stage Nitrizing Treatment are lower, and the temperature and resolution ratio of second stage Nitrizing Treatment are higher, carry out urging infiltration by energizer, obtain nitriding layer tissue.The present invention can effectively improve the nitriding speed and nitriding quality of Fe-Ni-Cr system high temperature alloy.
Description
Technical field
The invention belongs to thermo-chemical treatment fields, and in particular to a kind of Fe-Ni-Cr system high temperature alloy nitriding method.
Background technique
GH696 is a kind of using Fe-25Ni-12Cr as the high temperature alloy of matrix, comprehensive with a small amount of titanium, aluminium, molybdenum and trace B
It closes and strengthens, in 650 DEG C or less yield strengths with higher and lasting, creep strength and good high temperature elastomeric performance, resist
Exhaust gas corrosion performance and working plasticity are usually used in manufacturing the turbine of the long-term work at 650 DEG C or less and compressor fastener, diskware
With working-blade, turbine shroud, ring-shaped work pieces etc..Nitridation process is the effective way for improving such high temperature alloy performance.It is right
GH696 part carries out nitriding, can obtain high wearability and surface hardness, while improving the corrosion resistance of workpiece, make material
Material remains to maintain quite high hardness and higher counter-bending fatigue strength at 650 DEG C.And nitriding temperature is lower, therefore part is abnormal
Become very little.
But the nitridation process rate of GH696 is lower, is on the one hand because affecting between nitrogen-atoms in alloy rich in nickel
On the other hand gap solid solubility is because higher Cr content generates the passivating film of similar stainless steel, passivating film resistance in alloy surface
The infiltration of nitrogen-atoms is hindered.For conventionally employed one-step method gas nitriding technique to GH696 nitriding, Mean Speed is only 0.001mm/h.
Summary of the invention
It is an object of the invention to be directed to above-mentioned the problems of the prior art, a kind of Fe-Ni-Cr system high temperature alloy infiltration is provided
Nitrogen method effectively improves the nitriding speed of Fe-Ni-Cr system high temperature alloy, and nitriding is high-quality, and nitriding surface hardness can be made to meet technology
It is required that.
To achieve the goals above, Fe-Ni-Cr system high temperature alloy nitriding method of the invention the following steps are included:
S1, to Fe-Ni-Cr system high temperature alloy carry out nitriding pre-treatment, nitriding pre-treatment include 1000 DEG C at a temperature of
Solution treatment is carried out, then carries out ageing treatment in two times, the temperature of a timeliness is 850 DEG C, and the temperature of secondary ageing is 700
℃；
S2, the Fe-Ni-Cr system high temperature alloy Jing Guo nitriding pre-treatment is processed into sample and blast is carried out to outer surface；
S3, manufactured sample is subjected to two-step method Nitrizing Treatment, the temperature of first stage Nitrizing Treatment under nitrogen containing atmosphere
Lower with resolution ratio, the temperature and resolution ratio of second stage Nitrizing Treatment are higher, carry out urging infiltration by energizer, obtain nitriding layer
Tissue.
The step S2 carries out wind pressure≤0.2MPa when blast processing, and sand mold is the aluminum oxide of 120-220 mesh
Sand stands after blast and is no more than 2h and enters furnace.Step S3 is provided by purity nitrogen or pure ammonia carries out the nitrogenous of two-step method Nitrizing Treatment
Atmosphere.
The step S3 keeps the temperature 2h at 550 DEG C after first stage Nitrizing Treatment in two-step method Nitrizing Treatment,
The resolution ratio of ammonia is 20%, keeps the temperature 80h at 650 DEG C after second stage Nitrizing Treatment, and the resolution ratio of ammonia is 90%.
Energizer employed in the step S3 is the compound catalyst that titanium sponge and tetrachloro-ethylene are combined into.
The step S3 urge by energizer the specific steps of infiltration are as follows:
A. the step of adding titanium sponge is that 1:5 weighs titanium sponge and quartz sand respectively according to mass ratio, first sands flat quartz
It is laid on charging tray, then titanium sponge is laid on quartz sand, charging tray is placed in nitriding tooling bottom, is entered simultaneously with sample or part
Furnace；
B. the step of adding tetrachloro-ethylene, when temperature rises between 300~350 DEG C, tetrachloro-ethylene is sprayed into furnace.
The high-temperature alloy material that nitriding method of the present invention is directed to is GH696, and sample usesCylindrical body, obtain
After obtaining nitriding layer tissue, nitrided case depth is 0.15mm~0.25mm, and nitriding surface hardness is 89HR15N~93HR15N, center portion
Hardness is HB331~311 (d10/3000=3.35~3.45), nitrided case depth reaches a length of 82h when the nitriding of 0.18mm.
It is cooling in such a way that oil is cold after solution treatment in the step S1, furnace cooling after an ageing treatment, two
It is air-cooled after secondary ageing treatment.The soaking time of ageing treatment is 3h-5h, and the soaking time of secondary ageing processing is 16h.
Compared with prior art, the present invention have it is following the utility model has the advantages that Fe-Ni-Cr system high temperature alloy by solid solution and
Twice after ageing treatment, basis material can reach the final use state of part, and part is made to be able to maintain excellent mechanical property
Energy.Blast is carried out to outer surface before nitriding, passivating film can be removed, activates nitriding face, accelerates nitriding rate.By manufactured examination
Sample carries out two-step method Nitrizing Treatment under nitrogen containing atmosphere, and the first stage uses low temperature low decomposition ratio, and furnace atmosphere contains height at this time
The activated nitrogen atom of concentration seeps the stage to be strong, and a large amount of activated nitrogen atoms quickly penetrate into matrix surface, form high concentration high rigidity
Nitration case；Second stage uses high temperature high de-agglomeration rate, on the one hand, high de-agglomeration rate reduces activated nitrogen atom content in furnace, makes nitrogen
Diffusion of the atom from atmosphere to matrix reduces；On the other hand, temperature raising promotes diffusion of the nitrogen-atoms to matrix depths in matrix
Increase.It is compared with the fixed resolution ratio nitriding method of traditional fixed temperature, the advantages of two-step method nitriding is, nitrogen-atoms is to matrix
Internal diffusion is more abundant, and diffusion layer organization is more uniform, reduces that infiltration layer surface layer nitrogen atom concentration is excessively high to lead to infiltration layer embrittlement
Risk.
Further, the present invention carries out urging infiltration, four chloroethenes using the compound catalyst that titanium sponge and tetrachloro-ethylene are combined into
Alkene pyrolytic generates hydrogen chloride gas, can remove specimen surface passivating film, keeps workpiece surface clean, promotes the infiltration of nitrogen；
Titanium sponge has strong absorption to hydrogen, and nitrogen containing atmosphere is promoted to decompose, and provides more activated nitrogen atoms for nitriding process, adds
Fast nitriding rate.Simultaneously as absorption of the titanium sponge to hydrogen, reduces infiltration layer hydrogen content accordingly, this improves the hard of infiltration layer
Degree and toughness.It is only 0.001mm/h to the GH696 Mean Speed for carrying out nitriding using previous one-step method nitridation process, infiltration layer is deep
Degree needs 180h up to 0.18mm, a length of 82h when using two-step method nitridation process and urging the nitriding after infiltration method.
Detailed description of the invention
Metallograph under Fig. 1 high temperature alloy diffusion layer organization polishing state prepared by the present invention；
Diffusion layer organization metallograph of Fig. 2 high temperature alloy prepared by the present invention after the corrosion of 4% nitric acid alcohol.
Specific embodiment
Present invention will be described in further detail below with reference to the accompanying drawings.
Fe-Ni-Cr system high temperature alloy nitriding method of the present invention, comprising the following steps:
S1, Fe-Ni-Cr system high temperature alloy GH696 material is dissolved, oil it is cold, it is a timeliness, secondary ageing, air-cooled,
It is processed into sample, and blast processing is carried out to outer surface.Solid solubility temperature be 1000 DEG C, the type of cooling be oil it is cold, using it is secondary when
Effect processing, one time 850 DEG C of aging temp, furnace cooling is to 700 DEG C after keeping the temperature 3~5h, in 700 DEG C of progresss secondary ageings, keeps the temperature
It is air-cooled after 16h.The heat treatment process is the pre-treatment that must be carried out before nitriding, and GH696 matrix is the center of area after solid solution aging
Cube austenite grain, which is the final form of part core structure, must be carried out before nitriding.Sample outer surface is carried out
Wind pressure≤0.2MPa of blast processing, sand mold are 120-220 mesh aluminum oxide sand.Blast is removal specimen surface passivating film
Important method carries out uniform blast to the nitriding face of sample or part, and guarantees that entering furnace in 2h after blast carries out Nitrizing Treatment.
S2, sample made of step S1 is subjected under the nitrogen containing atmospheres such as purity nitrogen or pure ammonia two-step method Nitrizing Treatment, obtained
Nitriding layer tissue.The stage nitriding of two-step method Nitrizing Treatment use low temperature low decomposition ratio, 550 DEG C of holding temperature, soaking time
2h, the resolution ratio of ammonia are 20%；Second stage nitriding use high temperature high de-agglomeration rate, 650 DEG C of holding temperature, soaking time 80h,
The resolution ratio of ammonia is 90%.Nitriding efficiency is improved using the compound catalyst of titanium sponge and tetrachloro-ethylene composition, specific:
1. being that 1:5 weighs titanium sponge and quartz sand respectively according to mass ratio, quartz sand is laid on charging tray first, then will
Titanium sponge is laid on quartz sand, and charging tray is placed in nitriding tooling bottom, enters furnace simultaneously with sample or part；2. rising in temperature
When to during 300~350 DEG C, tetrachloro-ethylene is sprayed, into furnace to prevent sample Surface Creation passivating film in temperature-rise period.
Nitrided case depth 0.15mm~0.25mm, nitriding surface hardness 89HR15N~93HR15N, centre hardness HB331~
311(d10/3000=3.35~3.45), infiltration layer metallographic structure be not present more than depth of penetration half crackle, I grade of Brittleness.
Depth of penetration and metallographic structure are detected using metallographic method, from Fig. 1,2 visible nitrided case depth 0.18mm.
The chemical component of Fe-Ni-Cr system high temperature alloy GH696 is following (" China Aviation Materials Handbook " volume Two):
Supply status: hot rolling bar；
Heat treating regime (" compressor stator vane GH696 alloy hot rolled rod ", number: Q/703J20)；
Solid solution: 1000 ± 10 DEG C, oil is cold；
Timeliness: 850 ± 10 DEG C, 4~5h, furnace cooling is air-cooled in 700 ± 10 DEG C of 16~17h of heat preservation to 700 DEG C.
HB302~388.
Nitridation process test is carried out using Canadian NITREX numerical control nitriding furnace.
Embodiment 1: certain combustion engine ball-joint part nitridation process；
Accessory appearance is spherical shape, and having a size of S Φ 22.1 × hole Φ 7.93 × 11.9, outer surface of spheroid is nitriding face.
(1) dry blast；
Blast, wind pressure≤0.2MPa are carried out to part outer surface, sand mold is 120-220 mesh aluminum oxide sand.
Enter furnace nitriding after blast in 2h.
(2) nitriding；
Sample after blast is packed into NITREX numerical control nitriding furnace, sets soaking time, holding temperature, ammonia decomposition.
Design parameter is listed in the table below:
(3) infiltration layer detects；Depth of penetration is detected using metallographic method, using Rockwell hardness machine and Brinell's machine pair
Surface hardness and centre hardness are detected, and testing result is as shown in the table:
| Depth of penetration (mm) | Nitrided layer hardness (HR15N) | Centre hardness (HBW) | Brittleness | Crackle |
| 0.18 | 93 | 311-331 | I grade | It has no |
Embodiment 2: certain combustion engine sleeve part nitridation process；
Accessory appearance is tubular, and having a size of the 28.3 × hole Φ Φ 21.9 × 18, sleeve outer surface is nitriding face.
(1) dry blast；
Blast, wind pressure wind pressure≤0.2MPa are carried out to part outer surface, sand mold is 120-220 mesh aluminum oxide sand.
Enter furnace nitriding after blast in 2h.
(2) nitriding；
Sample after blast is packed into NITREX numerical control nitriding furnace, sets soaking time, holding temperature, ammonia decomposition.
Design parameter is listed in the table below:
(3) infiltration layer detects；Depth of penetration is detected using metallographic method, using Rockwell hardness machine and Brinell's machine
Surface hardness and centre hardness are detected, testing result is as shown in the table:
| Depth of penetration | Nitrided layer hardness | Centre hardness | Brittleness | Crackle |
| 0.20mm | 92HR15N | HBW311-331 | I grade | A small amount of crackle is less than depth of penetration half |
Embodiment 3: certain combustion engine ball movable joint part nitridation process
Accessory appearance be it is spherical, having a size of S Φ 32.1 × hole Φ 20.3 × 22, outer surface of spheroid is nitriding face.
(1) dry blast；
Blast, wind pressure≤0.2MPa are carried out to part outer surface, sand mold is 120-220 mesh aluminum oxide sand.
Enter furnace nitriding after blast in 2h.
(2) nitriding；
Sample after blast is packed into NITREX numerical control nitriding furnace, sets soaking time, holding temperature, ammonia decomposition；
Design parameter is listed in the table below:
(3) infiltration layer detects；Depth of penetration is detected using metallographic method, using Rockwell hardness machine and Brinell's machine
Surface hardness and centre hardness are detected, testing result is as shown in the table:
| Depth of penetration | Nitrided layer hardness | Centre hardness | Brittleness | Crackle |
| 0.22mm | 90.5HR15N | HBW311-331 | I grade | A small amount of crackle is less than depth of penetration half |
By the actually detected result of above three embodiments as it can be seen that passing through the available uniform nitration case group of this method
Knit, centre hardness is consistent with hardness after timeliness after nitriding, and nitrided case depth can reach 0.15mm~0.25mm, nitriding face it is hard
Degree can promote the use of in the nitridation process of the material in 89HR15N~93HR15N.
Claims (10)
1. a kind of Fe-Ni-Cr system high temperature alloy nitriding method, which comprises the following steps:
S1, to Fe-Ni-Cr system high temperature alloy carry out nitriding pre-treatment, nitriding pre-treatment include 1000 DEG C at a temperature of carry out
Then solution treatment carries out ageing treatment in two times, the temperature of a timeliness is 850 DEG C, and the temperature of secondary ageing is 700 DEG C；
S2, the Fe-Ni-Cr system high temperature alloy Jing Guo nitriding pre-treatment is processed into sample and blast is carried out to outer surface；
S3, manufactured sample carries out to two-step method Nitrizing Treatment under nitrogen containing atmosphere, the temperature of first stage Nitrizing Treatment and point
Solution rate is lower, and the temperature and resolution ratio of second stage Nitrizing Treatment are higher, carries out urging infiltration by energizer, obtains nitriding layer group
It knits.
2. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 1, it is characterised in that: step S2 carries out blast
Wind pressure≤0.2MPa when processing, sand mold are the aluminum oxide sand of 120-220 mesh, stand after blast and enter furnace no more than 2h.
3. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 1, it is characterised in that: the step S3 is logical
Purity nitrogen or pure ammonia are crossed to provide the nitrogen containing atmosphere for carrying out two-step method Nitrizing Treatment.
4. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 1, it is characterised in that: the step S3 exists
In two-step method Nitrizing Treatment, 2h is kept the temperature at 550 DEG C after first stage Nitrizing Treatment, the resolution ratio of ammonia is 20%, warp
80h is kept the temperature at 650 DEG C after crossing second stage Nitrizing Treatment, the resolution ratio of ammonia is 90%.
5. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 1, it is characterised in that: in the step S3
Used energizer is the compound catalyst that titanium sponge and tetrachloro-ethylene are combined into.
6. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 5, it is characterised in that:
The step S3 urge by energizer the specific steps of infiltration are as follows:
A. the step of adding titanium sponge is that 1:5 weighs titanium sponge and quartz sand respectively according to mass ratio, is first laid in quartz sand
On charging tray, then titanium sponge is laid on quartz sand, charging tray is placed in nitriding tooling bottom, enters furnace simultaneously with sample or part；
B. the step of adding tetrachloro-ethylene, when temperature rises between 300~350 DEG C, tetrachloro-ethylene is sprayed into furnace.
7. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 1, it is characterised in that: high-temperature alloy material is
GH696, sample areCylindrical body, obtain nitriding layer tissue after, nitrided case depth be 0.15mm~0.25mm,
Nitriding surface hardness is 89HR15N~93HR15N, and centre hardness is HB331~311 (d10/3000=3.35~3.45).
8. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 7, it is characterised in that: close GH696 high temperature
The nitrided case depth of golden material reaches a length of 82h when the nitriding of 0.18mm.
9. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 1, it is characterised in that: in the step S1
Cooling in such a way that oil is cold after solution treatment, furnace cooling after an ageing treatment is air-cooled after secondary ageing processing.
10. Fe-Ni-Cr system high temperature alloy nitriding method according to claim 1, it is characterised in that: the step S1
In an ageing treatment soaking time be 3h-5h, secondary ageing processing soaking time be 16h.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111945104A (en) * | 2020-08-17 | 2020-11-17 | 沈阳飞机工业（集团）有限公司 | Thin layer nitrocarburizing method |
| CN113564608A (en) * | 2021-03-02 | 2021-10-29 | 神华准格尔能源有限责任公司 | Method for integral hardening treatment of integral piston of diesel engine |
| CN116891970A (en) * | 2023-09-11 | 2023-10-17 | 宁波众远新材料科技有限公司 | Creep-resistant iron-nickel-based superalloy and preparation method thereof |
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| CN101942632A (en) * | 2010-09-21 | 2011-01-12 | 南京工业职业技术学院 | Gas nitriding process of 00Ni18Co8Mo5AlTi high-strength maraging steel |
| CN107858632A (en) * | 2017-12-04 | 2018-03-30 | 中国航发动力股份有限公司 | A kind of high Co-base alloy material part nitriding method |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111945104A (en) * | 2020-08-17 | 2020-11-17 | 沈阳飞机工业（集团）有限公司 | Thin layer nitrocarburizing method |
| CN113564608A (en) * | 2021-03-02 | 2021-10-29 | 神华准格尔能源有限责任公司 | Method for integral hardening treatment of integral piston of diesel engine |
| CN116891970A (en) * | 2023-09-11 | 2023-10-17 | 宁波众远新材料科技有限公司 | Creep-resistant iron-nickel-based superalloy and preparation method thereof |
| CN116891970B (en) * | 2023-09-11 | 2023-12-12 | 宁波众远新材料科技有限公司 | Creep-resistant iron-nickel-based superalloy and preparation method thereof |
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