CN117943500A - Eccentric forging forming method for reactor inner control rod transition piece shell - Google Patents
Eccentric forging forming method for reactor inner control rod transition piece shell Download PDFInfo
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Abstract
The invention discloses a forming method of an eccentric forging for a transition piece shell of a control rod in a reactor, which comprises the following steps of: designing and manufacturing a die and determining forging technology of a forging piece through a simulation technology; selecting steel ingots meeting forging requirements; forging the steel ingot according to a forging process and a die to obtain a primary forging; and machining the primary forging to obtain the final forging. The invention realizes the integral molding of the control rod shell forging, plays the roles of saving materials and shortening the processing period, and has the advantages of repeated utilization of the die after the process is solidified, high batch production efficiency and greatly improved product quality stability.
Description
Technical Field
The invention relates to the field of nuclear power station reactor equipment manufacturing, in particular to a method for forming eccentric forgings for control rod transition piece shells in a reactor.
Background
The control rod transition piece shell forging is applied to manufacturing of a control rod driving mechanism in a reactor internal component, is one of the components of a nuclear power plant reactor, is an important action component, has the function of controlling the reactor core reactivity, directly influences the operation reliability and safety of a nuclear reactor, and is one of indispensable nuclear power equipment.
In recent years, with the continuous upgrading of technology and the continuous improvement of the safe operation requirement of a nuclear power station, the magnetic force lifting type control rod driving mechanism becomes a main market product. According to the market depth investigation and development prospect prediction report of the China control rod driving mechanism industry of 2022-2027 published by the New Sitting industry research center, the control rod driving mechanism is required to have excellent high temperature resistance, high pressure resistance, corrosion resistance and radiation resistance because the control rod driving mechanism is contacted with a reactor coolant. Meanwhile, the reactor has various reactivity changes in the running process, the control rod driving mechanism moves very frequently, and the reactor is required to have excellent shock resistance, vibration resistance, wear resistance, running stability and easy maintenance. In general, the control rod driving mechanism has high requirements on structural design, material selection, manufacturing process and the like, and has high barriers for research and development of manufacturing technology. As one type of nuclear island equipment, the market space is increasing. The whole development level of nuclear power equipment in China is in an international advanced state, and the manufacturing strength of the control rod driving mechanism is also continuously enhanced.
Disclosure of Invention
In view of the defects existing at present, the invention provides the eccentric forging forming method for the control rod transition piece shell in the reactor, the forging piece of the control rod transition piece shell is manufactured by adopting a die forging process, the size of a forging stock is closer to that of a finished product, compared with the traditional process of adopting a square forging stock machine to machine and form, the material is saved, the machining period is shortened, the die after the process is solidified can be repeatedly utilized, the batch production efficiency is high, and the quality stability of the product is greatly improved.
In order to achieve the above purpose, the embodiment of the present invention adopts the following technical scheme:
A method of forming an eccentric forging for an in-reactor control rod transition piece enclosure, the method of forming an eccentric forging for an in-reactor control rod transition piece enclosure comprising:
Designing and manufacturing a die and determining forging technology of a forging piece through a simulation technology;
selecting steel ingots meeting forging requirements;
Forging the steel ingot according to a forging process and a die to obtain a primary forging;
and machining the primary forging to obtain the final forging.
According to one aspect of the invention, forging the steel ingot according to the forging process and the die to obtain a primary forging further comprises: forging the steel ingot through free forging to obtain a blank; and forging and forming the blank through a die to obtain the primary forging.
According to one aspect of the invention, forging a steel ingot by free forging to obtain a blank comprises: upsetting and drawing out the steel ingot, and refining grains; and in the last upsetting process, one end of the steel ingot is drawn to a preset size to form a tail part of the blank, the other end of the steel ingot is drawn to a preset size to form a head part of the blank, and the blank is obtained, wherein the tail part of the blank and a central shaft of the head part are eccentrically arranged, and the head part is thicker than the tail part in size.
According to one aspect of the invention, forging a steel ingot according to a forging process and a mold to obtain a primary forging includes: inserting the blank into a die, and adjusting the perpendicularity of the blank and the die; upsetting the head in a die to form a head circular cavity; turning over the blank and the die, upsetting the tail until forming; demolding the blank to obtain a primary forging; and forging and rounding the middle of the primary forging piece, and correcting the size.
According to one aspect of the invention, forging the steel ingot according to the forging process and the die to obtain a primary forging further comprises: and carrying out hydrogen diffusion treatment and normalizing heat treatment on the primary forging.
According to one aspect of the invention, the selecting of the ingot meeting the predetermined criteria comprises: selecting raw materials meeting forging requirements; smelting raw materials by using an alkaline electric furnace, and adding aluminum for tranquillization to obtain molten steel; vacuum refining the molten steel; and casting the molten steel into steel ingots in vacuum.
In accordance with one aspect of the present invention, designing and manufacturing a mold and determining a forging process for a forging by simulation techniques includes: establishing a multi-field coupling numerical simulation model for simulating the forging process of the forging; the forging process of the forging is subjected to numerical simulation research, so that the design of a die is finished, the manufacturing process flow of the die is determined, and the forging process of the forging is determined; and obtaining the die according to the design and manufacturing process flow of the die.
According to one aspect of the invention, the method further comprises the steps of: and before machining the primary forging, carrying out heat treatment on the primary forging.
According to one aspect of the invention, the pre-heat treatment roughing is performed before the heat treatment of the primary forging to remove fine cracks and wrinkles formed on the forging surface due to forging.
In accordance with one aspect of the invention, performance testing is performed on the primary forging prior to machining the primary forging.
The implementation of the invention has the advantages that: the invention relates to a method for forming an eccentric forging piece for a transition piece shell of a control rod in a reactor, which comprises the following steps: designing and manufacturing a die and determining forging technology of a forging piece through a simulation technology; selecting steel ingots meeting forging requirements; forging the steel ingot according to a forging process and a die to obtain a primary forging; and machining the primary forging to obtain the final forging. According to the invention, a numerical simulation model of multi-field coupling is established, a part of large forging test is replaced by computer simulation, numerical simulation research is carried out on the evolution process of a temperature field, a stress field, a strain field and a strain rate field of the forging, the flow state, defects and microstructure of metal, the defects of folding, streamline faults and the like in the forming process are solved by adopting an optimized die, and special die forming is adopted in the forming stage, so that the integral forming of the control rod shell forging is realized, the effects of saving materials and shortening the processing period are achieved, the die can be reused after the process is cured, the batch production efficiency is high, and the product quality stability is also greatly improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a molding method according to example 1 of the present invention;
FIG. 2 is a schematic diagram of a molding method according to embodiment 2 of the present invention;
FIG. 3 is a schematic diagram of a molding method according to embodiment 3 of the present invention;
FIG. 4 is a graph of a heat treatment process according to the present invention;
FIG. 5 is a flow chart of the forging of a steel ingot to obtain a primary forging according to the forging process and the die of the present invention;
FIG. 6 is a schematic view of a mold according to the present invention;
FIG. 7 is a schematic view of the structure of the primary forging of the present invention;
Fig. 8 is a graph of a process for forging a steel ingot to obtain a primary forging according to the forging process and the die of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1:
as shown in fig. 1 and 5-8, the eccentric forging forming method for the control rod transition piece shell in the reactor comprises the following steps:
S1: mold design and manufacturing through simulation technology and forging technology for determining forging
According to the size of the finished product of the forging, a numerical simulation model of multi-field coupling is established, and the forging process of the forging is simulated by adopting a finite element simulation technology; numerical simulation research is carried out on the evolution process of a temperature field, a stress field, a strain field and a strain rate field, the flow state, defects and microstructure of a metal in the forging process of the forging, the defects of folding, streamline faults and the like in the forming process are overcome by adopting an optimized die, simulation checking calculation is carried out by using a simulation technology, the size of a die cavity of the die is designed, the forging forming standard is ensured, the design of the die and the manufacturing process flow of the die are completed, and the forging process of the forging is determined; and obtaining the die according to the design and manufacturing process flow of the die.
In this embodiment, the design and manufacturing process flow of the mold is specifically forging drawing design, mold plan, design size and simulation, mold drawing design, mold forging, and mold processing.
In the present embodiment, the forging scheme is to forge into a cylinderMiddle beat/>Is a through hole of the substrate; and machining to the final size on a lathe.
S2: selecting steel ingot meeting forging requirements
In the embodiment, the SA-508Gr.3Cl.1 alloy steel is selected for forging. The purchasing of the material should be strictly performed according to the specification of chemical components, so as to minimize the existence of impurities and other harmful elements. The material can be smelted by adopting an alkaline electric furnace, aluminum adding and calm, vacuum refining and vacuum casting processes, and can also be smelted by adopting other equivalent or better processes capable of ensuring quality.
The embodiment adopts an alkaline electric furnace, aluminum addition calm, vacuum refining and vacuum casting technology to smelt the material, and the specific technological process is as follows: melting the materials to a mixing ratio, carrying out EF arc melting, LF external refining, VD vacuum degassing and vacuum casting. In order to ensure the purity and uniformity of the steel ingot, before and during casting the steel ingot, it is necessary to remove harmful gases such as hydrogen in the steel and to vacuum-treat the molten steel. And the vacuum system should be of sufficient energy to produce an evacuation capacity of less than 133 Pa. The contractor also has to provide a component list for ladle analysis. And analyzing chemical components of the product to be performed on the forging, and sampling and testing the inner surface of the end part of the forging corresponding to the head of the original steel ingot. The method of analyzing the chemical composition of the sample was carried out in accordance with the specification of ASME SA-751-2004.
The steel ingot chemical composition (melting analysis and finished product analysis) should meet the following table specifications:
S3: forging the steel ingot according to the forging process and the die to obtain a primary forging
When the steel ingot is forged, the initial forging temperature is more than or equal to 1150 ℃, the final forging temperature is more than or equal to 800 ℃, forging and pressing are carried out on a 5000-ton press, and the total forging ratio is about 11.1.
The forging forming process of this embodiment:
s3.1, free forging blank, tapping the surface of the steel ingot, hot cutting the head and the tail of the steel ingot, and blanking into 480 x 1200 of octagon;
The blanking into the octagonal shape can be beneficial to fixing during forging, and is more convenient and rapid during upsetting and drawing, so that the processing difficulty is effectively reduced;
S3.2, heating the steel ingot to not less than 1150 ℃, keeping the temperature for more than 1.5 hours, discharging, upsetting the steel ingot to 600, then drawing the steel ingot to be 480 x 1200 with star shape, and refining grains;
in actual forging, the steel ingot can be subjected to multiple upsetting and drawing, and grains are refined;
S3.3, heating the steel ingot to not less than 1150 ℃, preserving heat for more than 1.5 hours, discharging, upsetting the forging stock to 600, drawing one end of the steel ingot to 300 x 500 in eight directions to form a tail part of the blank, keeping the tail part to 800 lengths, and drawing the other end of the steel ingot to 600 To facilitate the molding and finally obtain the blank;
the tail part of the blank and the central shaft of the head part are eccentrically arranged, and the head part is thicker than the tail part in size;
S3.4, heating the blank to be more than or equal to 1150 ℃, keeping the temperature for more than 2 hours, discharging, inserting the blank into a die, enabling the head of the blank to be up and the tail to be down, adjusting the verticality of the blank and the die, upsetting the head in the die, forming the head in a circular cavity, turning over the blank and the die, enabling the tail of the blank to exceed a part of the die after turning over, upsetting the tail to be formed, and demoulding the blank into a primary forging; after the primary forging is manufactured, forging and rounding the middle of the primary forging, and correcting the size.
The verticality is less than or equal to 0.05.
The mold in this embodiment is a drain pan mold.
And (3) performing post-forging hydrogen diffusion and normalizing heat treatment according to technical requirements to prevent white point defects of the forged piece. And the quality of the forging is improved.
S4, machining the primary forging to obtain a final forging
And precisely machining the forging by adopting special machining equipment, so that the product size is ensured to meet the drawing requirement.
After the final forging is obtained, the final forging is subjected to the processes of size inspection, VT detection, UT detection, MT detection, PT detection, finished product identification, clean packaging, transportation and the like. The product is ensured to be qualified through multiple inspections.
Example 2:
As shown in fig. 2 and 5-8, the eccentric forging forming method for the control rod transition piece shell in the reactor comprises the following steps:
S1: mold design and manufacturing through simulation technology and forging technology for determining forging
According to the size of the finished product of the forging, a numerical simulation model of multi-field coupling is established, and the forging process of the forging is simulated by adopting a finite element simulation technology; performing numerical simulation research on the forging process of the forging, performing simulation checking calculation by using a simulation technology, designing the size of a die cavity, ensuring the forming standard of the forging, completing the design of the die, determining the manufacturing process flow of the die, and determining the forging process of the forging; and obtaining the die according to the design and manufacturing process flow of the die.
In this embodiment, the design and manufacturing process flow of the mold is specifically forging drawing design, mold plan, design size and simulation, mold drawing design, mold forging, and mold processing.
In the present embodiment, the forging scheme is to forge into a cylinderMiddle beat/>Is a through hole of the substrate; and machining to the final size on a lathe.
S2: selecting steel ingot meeting forging requirements
In the embodiment, the SA-508Gr.3Cl.1 alloy steel is selected for forging. The purchasing of the material should be strictly performed according to the specification of chemical components, so as to minimize the existence of impurities and other harmful elements. The material can be smelted by adopting an alkaline electric furnace, aluminum adding and calm, vacuum refining and vacuum casting processes, and can also be smelted by adopting other equivalent or better processes capable of ensuring quality.
The embodiment adopts an alkaline electric furnace, aluminum addition calm, vacuum refining and vacuum casting technology to smelt the material, and the specific technological process is as follows: melting the materials to a mixing ratio, carrying out EF arc melting, LF external refining, VD vacuum degassing and vacuum casting. In order to ensure the purity and uniformity of the steel ingot, before and during casting the steel ingot, it is necessary to remove harmful gases such as hydrogen in the steel and to vacuum-treat the molten steel. And the vacuum system should be of sufficient energy to produce an evacuation capacity of less than 133 Pa. The contractor also has to provide a component list for ladle analysis. And analyzing chemical components of the product to be performed on the forging, and sampling and testing the inner surface of the end part of the forging corresponding to the head of the original steel ingot. The method of analyzing the chemical composition of the sample was carried out in accordance with the specification of ASME SA-751-2004.
The steel ingot chemical composition (melting analysis and finished product analysis) should meet the following table specifications:
S3: forging the steel ingot according to the forging process and the die to obtain a primary forging
When the steel ingot is forged, the initial forging temperature is more than or equal to 1150 ℃, the final forging temperature is more than or equal to 800 ℃, forging and pressing are carried out on a 5000-ton press, and the total forging ratio is about 11.1.
The forging forming process of this embodiment:
s3.1, free forging blank, tapping the surface of the steel ingot, hot cutting the head and the tail of the steel ingot, and blanking into 480 x 1200 of octagon;
The blanking into the octagonal shape can be beneficial to fixing during forging, and is more convenient and rapid during upsetting and drawing, so that the processing difficulty is effectively reduced;
S3.2, heating the steel ingot to not less than 1150 ℃, keeping the temperature for more than 1.5 hours, discharging, upsetting the steel ingot to 600, then drawing the steel ingot to be 480 x 1200 with star shape, and refining grains;
in actual forging, the steel ingot can be subjected to multiple upsetting and drawing, and grains are refined;
S3.3, heating the steel ingot to not less than 1150 ℃, preserving heat for more than 1.5 hours, discharging, upsetting the forging stock to 600, drawing one end of the steel ingot to 300 x 500 in eight directions to form a tail part of the blank, keeping the tail part to 800 lengths, and drawing the other end of the steel ingot to 600 To facilitate the molding and finally obtain the blank;
the tail part of the blank and the central shaft of the head part are eccentrically arranged, and the head part is thicker than the tail part in size;
S3.4, heating the blank to be more than or equal to 1150 ℃, keeping the temperature for more than 2 hours, discharging, inserting the blank into a die, enabling the head of the blank to be up and the tail to be down, adjusting the verticality of the blank and the die, upsetting the head in the die, forming the head in a circular cavity, turning over the blank and the die, enabling the tail of the blank to exceed a part of the die after turning over, upsetting the tail to be formed, and demoulding the blank into a primary forging; after the primary forging is manufactured, forging and rounding the middle of the primary forging, and correcting the size.
The verticality is less than or equal to 0.05.
The mold in this embodiment is a drain pan mold.
And (3) performing post-forging hydrogen diffusion and normalizing heat treatment according to technical requirements to prevent white point defects of the forged piece. And the quality of the forging is improved.
S4: heat treating the primary forging
In order to achieve ideal performance indexes, according to the actual structural size of a product of a test product, measuring the actual temperature of the surface of the forging in the heating process by adopting a multipoint contact thermocouple, so that the temperature value is controlled more effectively; the maximum allowable deviation from the prescribed temperature of the heat treatment during the incubation period was + -10 deg.c.
And (3) carrying out Q (quenching) +T (tempering) heat treatment according to the technical requirements, wherein the heating temperature is 950-955 ℃, the heat preservation time is 3h25min, and the water cooling is carried out. T is that the heating temperature is 655-660 ℃, the heat preservation time is 5h and 35min, and the air cooling is carried out. The heat treatment process graph is shown in fig. 4.
S5, machining the primary forging to obtain a final forging
And precisely machining the forging by adopting special machining equipment, so that the product size is ensured to meet the drawing requirement.
After the final forging is obtained, the final forging is subjected to the processes of size inspection, VT detection, UT detection, MT detection, PT detection, finished product identification, clean packaging, transportation and the like. The product is ensured to be qualified through multiple inspections.
Example 3:
as shown in fig. 3 and 5-8, the eccentric forging forming method for the control rod transition piece shell in the reactor comprises the following steps:
S1: mold design and manufacturing through simulation technology and forging technology for determining forging
According to the size of the finished product of the forging, a numerical simulation model of multi-field coupling is established, and the forging process of the forging is simulated by adopting a finite element simulation technology; performing numerical simulation research on the forging process of the forging, performing simulation checking calculation by using a simulation technology, designing the size of a die cavity, ensuring the forming standard of the forging, completing the design of the die, determining the manufacturing process flow of the die, and determining the forging process of the forging; and obtaining the die according to the design and manufacturing process flow of the die.
In this embodiment, the design and manufacturing process flow of the mold is specifically forging drawing design, mold plan, design size and simulation, mold drawing design, mold forging, and mold processing.
In the present embodiment, the forging scheme is to forge into a cylinderMiddle beat/>Is a through hole of the substrate; and machining to the final size on a lathe.
S2: selecting steel ingot meeting forging requirements
In the embodiment, the SA-508Gr.3Cl.1 alloy steel is selected for forging. The purchasing of the material should be strictly performed according to the specification of chemical components, so as to minimize the existence of impurities and other harmful elements. The material can be smelted by adopting an alkaline electric furnace, aluminum adding and calm, vacuum refining and vacuum casting processes, and can also be smelted by adopting other equivalent or better processes capable of ensuring quality.
The embodiment adopts an alkaline electric furnace, aluminum addition calm, vacuum refining and vacuum casting technology to smelt the material, and the specific technological process is as follows: melting the materials to a mixing ratio, carrying out EF arc melting, LF external refining, VD vacuum degassing and vacuum casting. In order to ensure the purity and uniformity of the steel ingot, before and during casting the steel ingot, it is necessary to remove harmful gases such as hydrogen in the steel and to vacuum-treat the molten steel. And the vacuum system should be of sufficient energy to produce an evacuation capacity of less than 133 Pa. The contractor also has to provide a component list for ladle analysis. And analyzing chemical components of the product to be performed on the forging, and sampling and testing the inner surface of the end part of the forging corresponding to the head of the original steel ingot. The method of analyzing the chemical composition of the sample was carried out in accordance with the specification of ASME SA-751-2004.
The steel ingot chemical composition (melting analysis and finished product analysis) should meet the following table specifications:
S3: forging the steel ingot according to the forging process and the die to obtain a primary forging
When the steel ingot is forged, the initial forging temperature is more than or equal to 1150 ℃, the final forging temperature is more than or equal to 800 ℃, forging and pressing are carried out on a 5000-ton press, and the total forging ratio is about 11.1.
The forging forming process of this embodiment:
s3.1, free forging blank, tapping the surface of the steel ingot, hot cutting the head and the tail of the steel ingot, and blanking into 480 x 1200 of octagon;
The blanking into the octagonal shape can be beneficial to fixing during forging, and is more convenient and rapid during upsetting and drawing, so that the processing difficulty is effectively reduced;
S3.2, heating the steel ingot to not less than 1150 ℃, keeping the temperature for more than 1.5 hours, discharging, upsetting the steel ingot to 600, then drawing the steel ingot to be 480 x 1200 with star shape, and refining grains;
in actual forging, the steel ingot can be subjected to multiple upsetting and drawing, and grains are refined;
S3.3, heating the steel ingot to not less than 1150 ℃, preserving heat for more than 1.5 hours, discharging, upsetting the forging stock to 600, drawing one end of the steel ingot to 300 x 500 in eight directions to form a tail part of the blank, keeping the tail part to 800 lengths, and drawing the other end of the steel ingot to 600 To facilitate the molding and finally obtain the blank;
the tail part of the blank and the central shaft of the head part are eccentrically arranged, and the head part is thicker than the tail part in size;
S3.4, heating the blank to be more than or equal to 1150 ℃, keeping the temperature for more than 2 hours, discharging, inserting the blank into a die, enabling the head of the blank to be up and the tail to be down, adjusting the verticality of the blank and the die, upsetting the head in the die, forming the head in a circular cavity, turning over the blank and the die, enabling the tail of the blank to exceed a part of the die after turning over, upsetting the tail to be formed, and demoulding the blank into a primary forging; after the primary forging is manufactured, forging and rounding the middle of the primary forging, and correcting the size.
The verticality is less than or equal to 0.05.
The mold in this embodiment is a drain pan mold.
And (3) performing post-forging hydrogen diffusion and normalizing heat treatment according to technical requirements to prevent white point defects of the forged piece. And the quality of the forging is improved.
And S4, rough machining is carried out on the primary forging before heat treatment.
The purpose of rough machining before the forging is heat treatment is to remove the defects of fine cracks, wrinkles and the like formed on the surface of the sample piece due to forging. Thereby avoiding the possibility of defect amplification caused by the subsequent performance heat treatment stage. The machined surface is smooth, better ultrasonic detection can be performed, the unqualified quality problem inside the forge piece can be found in time, the forge piece can be repaired in time, and scrapping caused by defect amplification is prevented. Timely scrapping and feeding of unqualified parts can not be repaired, and subsequent processing waste of unqualified parts can be effectively prevented.
S5: heat treating the primary forging
In order to achieve ideal performance indexes, according to the actual structural size of a product of a test product, measuring the actual temperature of the surface of the forging in the heating process by adopting a multipoint contact thermocouple, so that the temperature value is controlled more effectively; the maximum allowable deviation from the prescribed temperature of the heat treatment during the incubation period was + -10 deg.c.
And (3) carrying out Q (quenching) +T (tempering) heat treatment according to the technical requirements, wherein the heating temperature is 950-955 ℃, the heat preservation time is 3h25min, and the water cooling is carried out. T is that the heating temperature is 655-660 ℃, the heat preservation time is 5h and 35min, and the air cooling is carried out. The heat treatment process graph is shown in fig. 4.
S6, performing performance detection on the primary forging
And sampling and detecting the performance of the primary forging according to the technical requirements of the product.
In the embodiment, the primary forging is sampled and the performance is detected, specifically, a sample is intercepted; simulating postweld heat treatment; processing a sample; physicochemical detection; rough machining is carried out on the sample; and (5) detecting UT. The simulated post-welding heat treatment is performed to ensure that the mechanical properties of the primary forging are not changed after the heat treatment, the physicochemical detection comprises chemical analysis, physical test and metallographic detection, various performance data of the primary forging can be detected, and Ultrasonic (UT) detection belongs to harmless detection, and mainly detects whether the surface of the primary forging is defective.
The performance examination requirements of physicochemical detection are shown in the following table:
the actual measurement data after physical and chemical detection in this embodiment are shown in the following table:
The flow requirements and actual measurement results of metallographic detection in physicochemical detection in this embodiment are as follows:
1) Microstructure of microstructure
The microscopic observation should be performed at 200 times magnification and a metallographic photograph taken, which is troostite.
2) Grain size (vertical section):
The grain size of the forging material is carried out according to the GB/T6394-2017 method, and the grain size is detected by amplifying 100 times. The actual grain size of the forging material should be finer than or equal to grade 5. Actual measurement was grade 6.5
3) Nonmetallic inclusion
The nonmetallic inclusion content of the forging material is rated according to ASTM E45-18 method A. The content of various nonmetallic inclusions meets the following requirements:
class A inclusions (coarse system and fine system) are less than or equal to 1.5 level, and 0/0 level is actually measured;
class B inclusions (coarse system and fine system) are less than or equal to 1.5 level, and 0/0 level is actually measured;
The level of C-type inclusion (coarse system and fine system) is less than or equal to 1.5, and the level is 0.5/0.5 actually measured;
Class D inclusions (coarse system and fine system) are less than or equal to 1.5 level, and the actual measured level is 0.5/0.5 level;
A+C is less than or equal to 2.0 level, and the actual measured level is 0.5/0.5 level;
B+D is less than or equal to 2.0 level, and the actual measured level is 0.5/0.5 level;
A+B+C+D is less than or equal to 4.0 level, and 1.0/1.0 level is actually measured;
s7, machining the primary forging piece to obtain a final forging piece
And precisely machining the forging by adopting special machining equipment, so that the product size is ensured to meet the drawing requirement.
After the final forging is obtained, the final forging is subjected to the processes of size inspection, VT detection, UT detection, MT detection, PT detection, finished product identification, clean packaging, transportation and the like. The product is ensured to be qualified through multiple inspections.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the technical scope of the present invention should be included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. The eccentric forging forming method for the reactor inner control rod transition piece shell is characterized by comprising the following steps of:
Designing and manufacturing a die and determining forging technology of a forging piece through a simulation technology;
selecting steel ingots meeting forging requirements;
Forging the steel ingot according to a forging process and a die to obtain a primary forging;
and machining the primary forging to obtain the final forging.
2. The method of forming an eccentric forging for a transition piece enclosure of a control rod in a reactor of claim 1, wherein forging a steel ingot according to a forging process and a mold to obtain a primary forging comprises: forging the steel ingot through free forging to obtain a blank; and forging and forming the blank through a die to obtain the primary forging.
3. The method of forming an eccentric forging for a reactor inner control rod transition piece shell according to claim 2, wherein forging the ingot by free forging to obtain a billet comprises: upsetting and drawing out the steel ingot, and refining grains; and in the last upsetting process, one end of the steel ingot is drawn to a preset size to form a tail part of the blank, the other end of the steel ingot is drawn to a preset size to form a head part of the blank, and the blank is obtained, wherein the tail part of the blank and a central shaft of the head part are eccentrically arranged, and the head part is thicker than the tail part in size.
4. A method of forming an eccentric forging for a transition piece enclosure for a control rod in a reactor as recited in claim 3, wherein forging a steel ingot according to a forging process and a mold to obtain a primary forging comprises: inserting the blank into a die, and adjusting the perpendicularity of the blank and the die; upsetting the head in a die to form a head circular cavity; turning over the blank and the die, upsetting the tail until forming; demolding the blank to obtain a primary forging; and forging and rounding the middle of the primary forging piece, and correcting the size.
5. The method of forming an eccentric forging for a reactor inner control rod transition piece shell according to claim 2, wherein forging the steel ingot according to the forging process and the mold to obtain a primary forging further comprises: and carrying out hydrogen diffusion treatment and normalizing heat treatment on the primary forging.
6. The method of forming eccentric forgings for in-reactor control rod transition piece shells according to claim 1, wherein said selecting a steel ingot meeting predetermined criteria comprises: selecting raw materials meeting forging requirements; smelting raw materials by using an alkaline electric furnace, and adding aluminum for tranquillization to obtain molten steel; vacuum refining the molten steel; and casting the molten steel into steel ingots in vacuum.
7. The method of forming an eccentric forging for a reactor inner control rod transition piece shell of claim 1, wherein designing and manufacturing a mold and determining a forging process by simulation techniques comprises: establishing a multi-field coupling numerical simulation model for simulating the forging process of the forging; the forging process of the forging is subjected to numerical simulation research, so that the design of a die is finished, the manufacturing process flow of the die is determined, and the forging process of the forging is determined; and obtaining the die according to the design and manufacturing process flow of the die.
8. The method of forming an eccentric forging for an in-reactor control rod transition piece enclosure of claim 1, further comprising the steps of: and before machining the primary forging, carrying out heat treatment on the primary forging.
9. The method for forming an eccentric forging for a transition piece shell of a control rod in a reactor according to claim 8, wherein the preliminary forging is subjected to preliminary working before being subjected to heat treatment, and fine cracks and wrinkles formed on the forging surface due to forging are removed.
10. The method of forming an eccentric forging for a transition piece shell of a control rod in a reactor according to any one of claims 1 to 9, wherein performance testing is performed on the primary forging prior to machining the primary forging.
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