CN108384936A - A kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging - Google Patents
A kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging Download PDFInfo
- Publication number
- CN108384936A CN108384936A CN201810148890.9A CN201810148890A CN108384936A CN 108384936 A CN108384936 A CN 108384936A CN 201810148890 A CN201810148890 A CN 201810148890A CN 108384936 A CN108384936 A CN 108384936A
- Authority
- CN
- China
- Prior art keywords
- carburizing steel
- forging
- wind turbine
- quenching
- turbine gearbox
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/28—Normalising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/60—Aqueous agents
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/009—Pearlite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Forging (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The present invention provides a kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging, includes the following steps：Step A：The wind power gear carburizing steel that forging is completed carries out the first quenching treatment using preheating, 3~4S is stopped for the wind power gear carburizing steel cool time, wherein the temperature for forging processing is maintained at 1160~1220 DEG C；Step B：Wind power gear carburizing steel after quenching treatment is subjected to first time high tempering processing.After the present invention utilizes residual forging heat quenching process, not only it had improved product quality but also had saved a large amount of energy consumption, the use of quenching medium enables to the index for having reached demand of carburizing steel hardness, avoid hardening break, by normalized treatment technique, acquisition is organized as pro-eutectoid pearlite and ferrite, does not occur bainite type non-equilibrium microstructure, meets the needs of technology with this, the processing after being is provided convenience.
Description
Technical field
The invention belongs to forging technology field more particularly to a kind of processing works of wind turbine gearbox carburizing steel heat treatment after forging
Skill.
Background technology
Carburizing steel be one kind can be subjected to carburizing and quenching make case hardness and wearability improve and center portion keep appropriate intensity and
The steel of toughness, carburizing steel are widely used in the gear manufacture of the industries such as wind-powered electricity generation, speed reducer, locomotive, existing carburizing steel gear,
It after forging molding, needs to carry out normalized treatment, then, after handling using conventional normalizing process, wherein also needing to carry out at quenching
Reason, quenching is that steel is heated to critical-temperature or more, then held for some time is cooled down with being more than critical cooling rate,
To obtain the unbalance microstructure based on martensite（Also with good grounds to need to obtain bainite or keep single phase austenite）One
Kind heat-treatment technology method, if but dealing with the hard of the carburizing steel that can lead to be obtained after quenching treatment improperly in this process
Degree is insufficient, for directly carrying out handling return after forging, prevents the waste heat after forging from adequately utilizing；In addition existing wind power gear
Box hardening steel there is being inconvenient to meet the problem of technology requires and is easy to impact carburizing steel in processing, in consideration of it,
The processing technology to carburizing steel heat treatment after forging is needed to make improvement.
Invention content
In order to solve the above technical problem, the present invention provides existing wind turbine gearbox carburizing steel is solved, there is inconveniences
Heat after a kind of wind turbine gearbox carburizing steel forging for the problem of meeting technology requirement and being easy to impact carburizing steel in processing
The processing technology of processing.
The technical solution adopted in the present invention is：A kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging, packet
Include following steps：
Step A：The wind power gear carburizing steel that forging is completed carries out the first quenching treatment using preheating, for wind power gear carburizing
The steel cool time stops 3~4S, wherein the temperature for forging processing is maintained at 1160~1220 DEG C；
Step B：Wind power gear carburizing steel after quenching treatment is subjected to first time high tempering processing；
Step C：The wind turbine gearbox carburizing steel that forging is completed is put into cabinet-type electric furnace and carries out process annealing processing, annealing time is
It 140~160 minutes, is cooled to room temperature, and used sawdust or cast-iron scrap is placed around in cabinet-type electric furnace, after process annealing
Wind turbine gearbox carburizing steel carry out roughing processing；
Step D：To the wind turbine gearbox carburizing steel normalized treatment after progress roughing；
Step E：To carry out normalized treatment after wind turbine gearbox carburizing steel be added quenching liquid carry out second of quenching treatment, first
Secondary quenching treatment uses fast quenching oil, third time quenching to use isothermal water quenching, and wherein soaking time is 3~5 hours, quenching temperature
Degree is 870~880 DEG C；
Step F：Second of temper is carried out to the wind turbine gearbox carburizing steel after quenching treatment, the type of cooling is adopted as wind
It is cold, 3~4 hours of time of tempering.
As present invention further optimization, the quenching medium in the step C includes the raw material by following weight
It is made：0.5~1 part of stearic acid, 10~15 parts of zinc chloride, 15~20 parts of sodium hydroxide, 75~85 parts of water, antifoaming agent 0.2~0.5
0.5~1 part of part, 3~5 parts of impurity and fungicide.
As present invention further optimization, the antifoaming agent is dimethyl silicone polymer.
As present invention further optimization, the fungicide is copper sulphate or Sandofan.
As present invention further optimization, in stepb, the air-cooled temperature of the first time high tempering is
620 DEG C~660 DEG C.
As present invention further optimization, in step D, the temperature of the normalizing is 940 DEG C.
As present invention further optimization, in step F, the holding temperature of described second tempering is 635 DEG C.
As present invention further optimization, in step D, the heat preserving mode of the normalizing is kept the temperature using constant-temperature oven.
The beneficial effects of the present invention are：After the present invention utilizes residual forging heat quenching process, product quality was not only improved but also had saved
About a large amount of energy consumption, the use of quenching medium enables to the index for having reached demand of carburizing steel hardness, avoids and quench
Fire cracking, by normalized treatment technique, acquisition is organized as pro-eutectoid pearlite and ferrite, and it is non-equilibrium not occur bainite type
Tissue, meets the needs of technology with this, and the processing after being is provided convenience, while also allowing for realizing flow line production, shortens
It production cycle, production efficiency is improved, the labor intensity of worker is in addition also mitigated, obtains significant economic benefit.
Specific implementation mode
Specific introduction is done to the present invention with reference to embodiment.
Embodiment one
The present embodiment is a kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging, is included the following steps：
Step A：The wind power gear carburizing steel that forging is completed carries out the first quenching treatment using preheating, for wind power gear carburizing
The steel cool time stops 3S, wherein the temperature for forging processing is maintained at 1160 DEG C；
Step B：Wind power gear carburizing steel after quenching treatment is subjected to first time high tempering processing, wherein air-cooled temperature is
620℃；
Step C：The wind turbine gearbox carburizing steel that forging is completed is put into cabinet-type electric furnace and carries out process annealing processing, annealing time is
It 140 minutes, is cooled to room temperature, and used sawdust or cast-iron scrap is placed around in cabinet-type electric furnace, to the wind after process annealing
Electrical gearbox carburizing steel carries out roughing processing；
Step D：To the wind turbine gearbox carburizing steel normalized treatment after progress roughing, the temperature of normalizing is 940 DEG C, using
Constant-temperature oven is kept the temperature；
Step E：To carry out normalized treatment after wind turbine gearbox carburizing steel be added quenching liquid carry out second of quenching treatment, first
Secondary quenching treatment uses fast quenching oil, third time quenching to use isothermal water quenching, and wherein soaking time is 3 hours, hardening heat
It is 870 DEG C；
Step F：Second of temper is carried out to the wind turbine gearbox carburizing steel after quenching treatment, the type of cooling is adopted as wind
Cold, 3 hours of time of tempering, holding temperature is 635 DEG C.
Quenching medium in the present embodiment includes being made by the raw material of following weight：0.5 part of stearic acid, zinc chloride 10
Part, 15 parts of sodium hydroxide, 75 parts of water, 0.2 part of dimethyl silicone polymer, 3 parts of impurity and 0.5 part of copper sulphate.
Embodiment two
The present embodiment is a kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging, is included the following steps：
Step A：The wind power gear carburizing steel that forging is completed carries out the first quenching treatment using preheating, for wind power gear carburizing
The steel cool time stops 3.5S, wherein the temperature for forging processing is maintained at 1200 DEG C.
Step B：Wind power gear carburizing steel after quenching treatment is subjected to first time high tempering processing, wherein air-cooled temperature
Degree is 640 DEG C.
Step C：Wind turbine gearbox carburizing steel that forging is completed is put into cabinet-type electric furnace and carries out process annealing processing, when annealing
Between be 150 minutes, be cooled to room temperature, and used sawdust or cast-iron scrap are placed around in cabinet-type electric furnace, after process annealing
Wind turbine gearbox carburizing steel carry out roughing processing；
Step D：To the wind turbine gearbox carburizing steel normalized treatment after progress roughing, the temperature of normalizing is 940 DEG C, using
Constant-temperature oven is kept the temperature.
Step E：Quenching liquid is added to the wind turbine gearbox carburizing steel after progress normalized treatment and carries out second of quenching treatment,
First time quenching treatment uses fast quenching oil, third time quenching to use isothermal water quenching, and wherein soaking time is 4 hours, quenching
Temperature is 875 DEG C.
Step F：Second of temper is carried out to the wind turbine gearbox carburizing steel after quenching treatment, the type of cooling is adopted as
Air-cooled, 3.5 hours of time of tempering, holding temperature is 635 DEG C.
Quenching medium in the present embodiment includes being made by the raw material of following weight：0.8 part of stearic acid, zinc chloride 12
Part, 18 parts of sodium hydroxide, 80 parts of water, 0.4 part of dimethyl silicone polymer, 4 parts of impurity and 0.8 part of copper sulphate.
Embodiment three
The present embodiment is a kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging, is included the following steps：
Step A：The wind power gear carburizing steel that forging is completed carries out the first quenching treatment using preheating, for wind power gear carburizing
The steel cool time stops 4S, wherein the temperature for forging processing is maintained at 1220 DEG C.
Step B：Wind power gear carburizing steel after quenching treatment is subjected to first time high tempering processing, wherein air-cooled temperature
Degree is 660 DEG C.
Step C：Wind turbine gearbox carburizing steel that forging is completed is put into cabinet-type electric furnace and carries out process annealing processing, when annealing
Between be 160 minutes, be cooled to room temperature, and used sawdust or cast-iron scrap are placed around in cabinet-type electric furnace, after process annealing
Wind turbine gearbox carburizing steel carry out roughing processing；
Step D：To the wind turbine gearbox carburizing steel normalized treatment after progress roughing, the temperature of normalizing is 940 DEG C, using
Constant-temperature oven is kept the temperature.
Step E：Quenching liquid is added to the wind turbine gearbox carburizing steel after progress normalized treatment and carries out second of quenching treatment,
First time quenching treatment uses fast quenching oil, third time quenching to use isothermal water quenching, and wherein soaking time is 5 hours, quenching
Temperature is 880 DEG C.
Step F：Second of temper is carried out to the wind turbine gearbox carburizing steel after quenching treatment, the type of cooling is adopted as
Air-cooled, 4 hours of time of tempering, holding temperature is 635 DEG C.
Quenching medium in the present embodiment includes being made by the raw material of following weight：1 part of stearic acid, zinc chloride 15
Part, 20 parts of sodium hydroxide, 85 parts of water, 0.5 part of dimethyl silicone polymer, 5 parts of impurity and 1 part of copper sulphate.
To sum up, the present invention is disappeared using after residual forging heat quenching process, not only having improved product quality but also saved a large amount of energy
Consumption, the use of quenching medium enable to the index for having reached demand of carburizing steel hardness, hardening break are avoided, at normalizing
Science and engineering skill, acquisition are organized as pro-eutectoid pearlite and ferrite, do not occur bainite type non-equilibrium microstructure, meet technology with this
Demand, the processing after being provides convenience, while also allowing for realizing flow line production, shortens the production cycle, improves
In addition production efficiency also mitigates the labor intensity of worker, obtain significant economic benefit.
The above is only the preferred embodiment of patent of the present invention, it is noted that for the common skill of the art
For art personnel, under the premise of not departing from patent principle of the present invention, several improvements and modifications can also be made, these improve and
Retouching also should be regarded as the protection domain of patent of the present invention.
Claims (8)
1. a kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging, which is characterized in that include the following steps：
Step A：The wind power gear carburizing steel that forging is completed carries out the first quenching treatment using preheating, for wind power gear carburizing
The steel cool time stops 3~4S, wherein the temperature for forging processing is maintained at 1160~1220 DEG C；
Step B：Wind power gear carburizing steel after quenching treatment is subjected to first time high tempering processing；
Step C：The wind turbine gearbox carburizing steel that forging is completed is put into cabinet-type electric furnace and carries out process annealing processing, annealing time is
It 140~160 minutes, is cooled to room temperature, and used sawdust or cast-iron scrap is placed around in cabinet-type electric furnace, after process annealing
Wind turbine gearbox carburizing steel carry out roughing processing；
Step D：To the wind turbine gearbox carburizing steel normalized treatment after progress roughing；
Step E：To carry out normalized treatment after wind turbine gearbox carburizing steel be added quenching liquid carry out second of quenching treatment, first
Secondary quenching treatment uses fast quenching oil, third time quenching to use isothermal water quenching, and wherein soaking time is 3~5 hours, quenching temperature
Degree is 870~880 DEG C；
Step F：Second of temper is carried out to the wind turbine gearbox carburizing steel after quenching treatment, the type of cooling is adopted as wind
It is cold, 3~4 hours of time of tempering.
2. the processing technology of wind turbine gearbox carburizing steel heat treatment after forging as described in claim 1, which is characterized in that the step
Quenching medium in rapid C includes being made by the raw material of following weight：0.5~1 part of stearic acid, 10~15 parts of zinc chloride, hydrogen
0.5~1 part of 15~20 parts of sodium oxide molybdena, 75~85 parts of water, 0.2~0.5 part of antifoaming agent, 3~5 parts of impurity and fungicide.
3. the processing technology of wind turbine gearbox carburizing steel heat treatment after forging as claimed in claim 2, which is characterized in that described
Antifoaming agent is dimethyl silicone polymer.
4. the processing technology of wind turbine gearbox carburizing steel heat treatment after forging as claimed in claim 2, which is characterized in that described
Fungicide is copper sulphate or Sandofan.
5. the processing technology of wind turbine gearbox carburizing steel heat treatment after forging as described in claim 1, which is characterized in that in step
In B, the air-cooled temperature of the first time high tempering is 620 DEG C~660 DEG C.
6. the processing technology of wind turbine gearbox carburizing steel heat treatment after forging as described in claim 1, which is characterized in that in step
In D, the temperature of the normalizing is 940 DEG C.
7. the processing technology of wind turbine gearbox carburizing steel heat treatment after forging as described in claim 1, which is characterized in that in step
In F, the holding temperature of described second tempering is 635 DEG C.
8. the processing technology of wind turbine gearbox carburizing steel heat treatment after forging as described in claim 1, which is characterized in that in step
In D, the heat preserving mode of the normalizing is kept the temperature using constant-temperature oven.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810148890.9A CN108384936A (en) | 2018-02-13 | 2018-02-13 | A kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810148890.9A CN108384936A (en) | 2018-02-13 | 2018-02-13 | A kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108384936A true CN108384936A (en) | 2018-08-10 |
Family
ID=63069398
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810148890.9A Pending CN108384936A (en) | 2018-02-13 | 2018-02-13 | A kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108384936A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109402359A (en) * | 2018-11-06 | 2019-03-01 | 包头钢铁（集团）有限责任公司 | A kind of heat treatment method of gear steel |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101314202A (en) * | 2008-06-02 | 2008-12-03 | 江阴振宏重型锻造有限公司 | Method for producing wind-electricity principal axis with gathering stock full fibre upset forging |
| CN101524813A (en) * | 2009-04-01 | 2009-09-09 | 重庆歇马机械曲轴有限公司 | Waste heat hardening and tempering process of motorcycle crank forged piece |
| CN102494106A (en) * | 2011-12-26 | 2012-06-13 | 重庆清平机械厂 | Process for manufacturing 20 CrMo carburizing steel gear |
| CN102965588A (en) * | 2012-11-29 | 2013-03-13 | 南车戚墅堰机车车辆工艺研究所有限公司 | Low-alloy high-strength cast steel, and smelting and heat treatment method thereof |
| CN106702099A (en) * | 2017-01-18 | 2017-05-24 | 抚顺特殊钢股份有限公司 | Large-size 42 CrMo4 hardened and tempered steel manufacturing process for wind power gearbox outer main shaft |
-
2018
- 2018-02-13 CN CN201810148890.9A patent/CN108384936A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101314202A (en) * | 2008-06-02 | 2008-12-03 | 江阴振宏重型锻造有限公司 | Method for producing wind-electricity principal axis with gathering stock full fibre upset forging |
| CN101524813A (en) * | 2009-04-01 | 2009-09-09 | 重庆歇马机械曲轴有限公司 | Waste heat hardening and tempering process of motorcycle crank forged piece |
| CN102494106A (en) * | 2011-12-26 | 2012-06-13 | 重庆清平机械厂 | Process for manufacturing 20 CrMo carburizing steel gear |
| CN102965588A (en) * | 2012-11-29 | 2013-03-13 | 南车戚墅堰机车车辆工艺研究所有限公司 | Low-alloy high-strength cast steel, and smelting and heat treatment method thereof |
| CN106702099A (en) * | 2017-01-18 | 2017-05-24 | 抚顺特殊钢股份有限公司 | Large-size 42 CrMo4 hardened and tempered steel manufacturing process for wind power gearbox outer main shaft |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109402359A (en) * | 2018-11-06 | 2019-03-01 | 包头钢铁（集团）有限责任公司 | A kind of heat treatment method of gear steel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109082587A (en) | The manufacturing method of high-carbon high nickel steel ring forging used for wind power generation | |
| CN102230062A (en) | Heat treatment process for improving strength and toughness of 9SiCr die steel | |
| CN103266212A (en) | Thermal treatment technology for improving low-temperature impact toughness of 25Cr2Ni4MoV steel forging | |
| CN102392107A (en) | Quenching method for 20Cr13-40Cr13 martensite stainless steel | |
| CN107881303A (en) | Steel annealing process | |
| CN109811114A (en) | A kind of fine grain intensive quenching cooling means of steel | |
| CN104532140B (en) | A kind of large scale shield machine is steel and heat treatment method thereof for bearing ring | |
| CN106011396A (en) | Quenching method for improving mechanical property of large forging | |
| CN101660036A (en) | Heat treating method of high strength and high ductility steel tube | |
| CN104451438A (en) | Production method of high-strength gear | |
| CN106555131B (en) | A kind of Super High Carbon profile shaft holds Heat-Treatment of Steel method | |
| CN113801978B (en) | Heat treatment method for improving strength and toughness of bearing steel 8Cr4Mo4V | |
| CN102758068A (en) | Heat treatment method of GCr15 steel | |
| CN103820705A (en) | Performance heat treatment method for SA508-3 large forging for nuclear power vessel | |
| CN1159461C (en) | Deep-cold treating technology of steel workpiece | |
| CN108384936A (en) | A kind of processing technology of wind turbine gearbox carburizing steel heat treatment after forging | |
| CN102212664B (en) | Heat treatment method of stainless steel traction pin | |
| CN105112634A (en) | Heat treatment process for hot-working die | |
| CN111100976A (en) | Heat treatment process for preventing cracking of steel for glass mold after forging | |
| CN102699645A (en) | Isothermal normalizing process for gear of wind driven generator | |
| CN102732710B (en) | Heat treatment method of steel plate with large thickness | |
| CN102337453A (en) | Method for improving plastic deformation resistance of low-carbon structural steel | |
| CN104404219A (en) | Spring heat treatment method | |
| CN102181787A (en) | Refractory corrosion-resisting steel as well as preparation and heat treatment method thereof | |
| CN104532166A (en) | Manufacturing method of wear-resisting gear |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20180810 |
|
| RJ01 | Rejection of invention patent application after publication |