CN103056603A - Preparation method for vibration-proof strip assembly for CAP1400 nuclear power generating set vapor generator - Google Patents

Abstract

A method for preparing an anti-vibration bar assembly of a steam generator of a CAP1400 unit, comprising: preparation of an anti-vibration bar, preparation of an end cap, bending forming, assembly of an end cap, upsetting, inspection, cleaning and packaging. The anti-vibration bar assembly of the steam generator of the CAP1400 unit described in the present invention has a simple structure, and the product quality meets the precision requirements for the anti-vibration bar of the steam generator in a nuclear power plant, and is safer in use. The preparation method of the anti-vibration strip, through strict preparation procedures, ensures the technical requirements for the anti-vibration strip assembly of the steam generator in the nuclear power plant, ensures the quality, and improves the safety.

Description

Preparation method of anti-vibration bar assembly of steam generator of CAP1400 nuclear power unit

technical field

The invention relates to a preparation method of an anti-vibration bar assembly of a steam generator of a CAP1400 nuclear power unit. the

Background technique

CAP1400 is the code name of the major special demonstration project of pressurized water reactor, which refers to the advanced passive nuclear power technology with an installed capacity of more than 1.4 million kilowatts in my country. the

The U-shaped heat transfer tube in a nuclear power plant is the most critical and weakest link in the pressure boundary of the primary circuit system. Once the heat transfer tube is damaged by vibration, the steam generator must be replaced, which will inevitably cause a huge waste of manpower, financial resources and incidents, and also increase the risk of radioactive radiation for maintenance personnel. Therefore, solving the steam generator tube failure accident is a key issue related to the safety of the nuclear power plant and to make the nuclear power plant competitive and viable. the

In order to eliminate the source of vibration as much as possible, it is generally necessary to install anti-vibration strips at the elbow of the U-shaped heat transfer tube in the steam generator. How to provide an anti-vibration strip assembly with good anti-vibration performance, which is convenient, simple, and high-precision The preparation method is a technical problem in this field. the

Contents of the invention

The technical problem to be solved by the present invention is to provide a preparation method of the anti-vibration bar assembly of the steam generator of the CAP1400 nuclear power unit with good anti-vibration performance. the

In order to solve the above-mentioned technical problems, the present invention provides a preparation method of the anti-vibration bar assembly of the steam generator of the CAP1400 nuclear power unit. The anti-vibration strip assembly includes: a V-shaped anti-vibration strip and end caps respectively arranged at both ends of the anti-vibration strip; the cross-section of the anti-vibration strip is rectangular, and the cross-section of the end cap is back-shaped to facilitate the anti-vibration strip The anti-vibration bar and the end cap are fixed by upsetting pressure to facilitate the fixing of the anti-vibration bar and the end cap through upsetting pressure; the anti-vibration bar is made of 405 stainless steel; the end cap is made of 690 nickel-based alloy material, and the U-shaped The heat transfer tube is also a nickel-based alloy material, and the two materials are the same, so that the U-shaped heat transfer tube and the end cap can be welded and fixed conveniently. The 690 nickel-based alloy material also has the characteristics of strong corrosion resistance. The preparation method includes: anti-vibration bar bending forming process: cutting the anti-vibration bar according to the total length of the required size plus 50mm allowance, bending the anti-vibration bar at a set angle, and the anti-vibration bar after bending The bar is placed on a surface grinder to grind the corner thickening area. the

The preparation method of the anti-vibration strip assembly also includes: the process of assembling the end cap: gently scrub the surface of the end cap and the inner hole formed by wire cutting with alcohol, and clean the stainless steel bar with alcohol at the same time, after cleaning, Remove burrs, bite marks, protruding metal or sharp corners; then insert the end of the stainless steel rod into the cap end, aligning the angle for assembly. the

The preparation method of the anti-vibration bar assembly also includes: an upsetting process, including: (1) pull-off force process evaluation: the pull-off force evaluation is performed on the end cap after assembly and upsetting, so that the cap is under the minimum pull force, The position does not move; the end pull-off force under different pressures is recorded, and the most suitable pressure is selected as the pressure process parameter in the upsetting process; (2) Upsetting pressure: put the cap end into the upsetting mold, Use a hydraulic press to upset the central position of the end cap and the positions adjacent to both ends of the end cap on the anti-vibration strip, press down and position, keep the pressure for 10 seconds, and then unload. There are four upsetting positions on the anti-vibration strip, two adjacent to the end of the end cap, which are used to limit the end of the cap and prevent the displacement of the end cap on the anti-vibration strip. the

A method for preparing the above-mentioned anti-vibration bar bar includes the following steps in sequence: induction furnace smelting, forging, hot rolling, first heat treatment, cold drawing, second heat treatment, and finished product processing. the

The induction furnace smelting: when the alloy material is smelted, a nickel plate, pure iron, and metal chromium are placed at the bottom of the induction furnace, and they are mixed and compacted. After melting 70%, 2% of the total weight of the slag is added for steelmaking, and the measured After the temperature of the molten steel reaches the tapping temperature, pour the molten steel into the ladle, calm down for 1-2 minutes and pour it into a steel ingot, which effectively improves the purity and uniformity of the alloy steel, improves the surface and internal quality of the steel ingot, and improves the quality of the alloy. properties of steel. the

The anti-vibration bar alloy material is required to be pure; the chemical composition is accurate and uniform; and it has a specified organizational state. There are a number of indisputable advantages to using an induction hob. Because it has no pollution sources that exist in other equipment, it can guarantee the purest metal material for carbon and other impurities; it can ensure the uniformity of the alloy because of the electrodynamic stirring of the metal pool; it can ensure that the metal is accurately obtained and maintained. The required temperature and the uniform distribution of temperature along the entire molten pool temperature; eliminate local overheating; because of its fast melting speed and less metal burning loss, it creates favorable conditions for accurately obtaining the specified alloy composition and the least element burning loss; in the improvement It is highly mobile when refining metals whose chemical composition differs from that of the forehearth. the

The forging: the steel ingot of the anti-vibration bar alloy material smelted by the induction furnace is heated and kept at 1150-1220°C and then forged into a steel billet with a size of 50*50mm; after the surface is finished and ground, it is sent to the next step of hot rolling blank process . the

Forging is a processing method that uses forging machinery to exert pressure on metal blanks to cause plastic deformation to obtain forgings with certain mechanical properties, certain shapes and sizes. Forging can eliminate the as-cast looseness of metals during the smelting process. Defects, optimize the microstructure, and because the complete metal flow line is preserved, the mechanical properties of forgings are generally better than castings of the same material. For important parts with high loads and severe working conditions in related machinery, forgings are mostly used, except for plates, profiles or weldments that can be rolled with simpler shapes. Generally speaking, forging is the first step in material processing called "blank opening". the

The hot rolling: the anti-vibration bar alloy material 50×50mm blank is placed at a temperature of 1050-1100° C., heated and kept warm, and then hot-rolled to form a bar of ф16mm. the

The anti-vibration bar alloy material is forged into a 50×50mm blank and rolled into steel products of various geometric cross-sectional shapes by means of heating. According to the shape of the steel section, it can be divided into three types: simple section, complex section or special-shaped section and periodic section. the

(1) Hot rolling can significantly reduce energy consumption and cost. The metal has high plasticity and low deformation resistance during hot rolling, which greatly reduces the energy consumption of metal deformation. the

(2) Hot rolling can improve the processing performance of metals and alloys, that is, the coarse grains in the cast state are broken, the cracks are significantly healed, the casting defects are reduced or eliminated, the cast structure is transformed into a refined deformed structure, and the processing of the alloy is improved. performance. the

(3) The anti-vibration bar alloy material is rolled with a large hot-rolled ingot and a large reduction, which not only improves the production efficiency, but also creates conditions for increasing the rolling speed and realizing the continuity and automation of the rolling process. the

(4) The hot rolling process actually belongs to the intermediate processing process and is an important step in forming the finished blank. the

The first heat treatment: in order to ensure the surface quality of the anti-vibration bar alloy material, the hot-rolled bar is subjected to surface finishing and grinding, and then vacuum annealing treatment is carried out. Heating and heat preservation were carried out at 10°C. the

Intermediate heat treatment, also called pre-heat treatment, is a heat treatment set up to eliminate the defects of the previous process or to make the subsequent process easy to process. It is a metal heat treatment process that slowly heats the metal to a certain temperature, maintains it for a sufficient time, and then cools it at an appropriate speed. the

Annealing heat treatment is divided into complete annealing, incomplete annealing and stress relief annealing. The mechanical properties of annealed materials can be detected by tensile test or hardness test. the

Purpose of stress annealing:

① Improve or eliminate various structural defects and residual stresses caused by steel casting, forging, rolling and welding, and prevent deformation and cracking of workpieces. the

② Soften the workpiece for cutting. the

③Refine the grain and improve the structure to improve the mechanical properties of the workpiece. the

④ Make organizational preparations for final heat treatment (quenching, tempering). the

The cold drawing: first perform softening and annealing treatment, and keep warm for 40 minutes at a temperature of 720-750°C; draw sequentially with a polycrystalline mold according to the deformation requirements, and grind the micro-cracks on the surface until there is no defect. Do the next pull. the

Cold drawing is a production method in which the hot-rolled anti-vibration bar alloy bar is softened and annealed and then reprocessed in a cold state to obtain various precision and high-precision products or intermediate products. the

The second heat treatment: the anti-vibration bar alloy bar is drawn to the finished material and spread in a bell-type heat treatment furnace, and heat treatment is carried out under the protection of hydrogen. , and then slowly cool to below 610°C at a cooling rate not exceeding 28°C/hour, and then air-cool to room temperature. the

Metal heat treatment is one of the important processes in mechanical manufacturing. Compared with other processing techniques, heat treatment generally does not change the shape and overall chemical composition of the workpiece, but changes the microstructure inside the workpiece or changes the chemical composition of the surface of the workpiece. , to give or improve the performance of the workpiece. It is characterized by improving the intrinsic quality of the workpiece, which is generally not visible to the naked eye. the

In order to make metal workpieces have the required mechanical properties, physical properties and chemical properties, in addition to reasonable selection of materials and various forming processes, heat treatment processes are often essential. Steel is the most widely used material in the machinery industry. The microstructure of steel is complex and can be controlled by heat treatment. Therefore, the heat treatment of steel is the main content of metal heat treatment. In addition, aluminum, copper, magnesium, titanium, etc. and their alloys can also change their mechanical, physical and chemical properties through heat treatment to obtain different performance. the

The finished product processing: straightening and polishing the processed bar. the

Straightening: Correcting the shape defects of metal plastic processing products is one of the important finishing processes. Various shape defects often occur in the production process of cold drawn materials or in the subsequent cooling and transportation processes, such as profile pipes Bending, waves, scooping, etc., through various straightening equipment, defects such as bending can be eliminated under the action of external force, so that the product can reach a qualified and ideal state. the

Polishing: (1) Coarse grinding: In addition to making the surface smooth and flat, the polishing of the product should minimize surface damage as much as possible. Each polishing process must remove the deformed layer caused by the previous process (at least the deformed layer produced by the previous process should be reduced to the depth of the deformed layer produced by this process), rather than just remove the wear marks of the previous process; at the same time, The process itself should minimize damage to facilitate the next process. The depth of the deformed layer produced by the last polishing process should be very shallow to ensure that it can be removed in the next polishing process. Care should be taken during this process to prevent the metal from overheating. the

(2) Fine grinding: The purpose of fine grinding is to eliminate the deep grinding marks left by rough grinding and lay a good foundation for the next step of polishing. Fine grinding is usually carried out on sandpaper, which is divided into water sandpaper and metallographic sandpaper. Usually water sandpaper is SiC abrasive which is insoluble in water. The abrasive of metallographic sandpaper includes artificial corundum, silicon carbide, iron oxide, etc., which are extremely hard and have polygonal edges and corners. They have good cutting performance. Water can be used as lubricant for fine grinding. Manual wet grinding or mechanical wet grinding, usually use four types of water sandpaper with a particle size of 240, 320, 400, and 600 to polish before polishing. For softer metals, use finer metallographic sandpaper to polish before polishing. The sandpaper slopes outwards and downwards (viewed from the operator’s direction). When sticking it on the flat glass for grinding, put the sample on the sandpaper and push it straight forward to leave the sandpaper. Repeat this until the old All the wear marks disappear, and new wear marks with uniform direction are obtained on the entire grinding surface. Before each sandpaper is changed, the sand particles on the sample and hands must be washed with water and dried, and then the sample is rotated 90° Sand on secondary sandpaper. During use, the flowing water continuously flows over the surface of the sandpaper, washing away most of the abrasive debris and fallen abrasive grains in time. In this way, during the entire polishing operation, the sharp edges and corners of the abrasive grains are always in contact with the surface of the sample, maintaining its good grinding effect. Another advantage of the wet grinding method is that the cooling effect of water can reduce the frictional heat generated on the surface of the sample during polishing and avoid changes in the microstructure. The whole polishing process can be completed on the same equipment. the

The preparation method of the above-mentioned end cap sequentially includes the following steps: induction furnace smelting, forging, hot rolling, heat treatment, and end cap turning. the

The induction furnace smelting: when the alloy material is smelted, a nickel plate, pure iron, and metal chromium are placed at the bottom of the induction furnace, and they are mixed and compacted. After melting 70%, 2% of the total weight of the slag is added for steelmaking, and the measured After the molten steel temperature reaches the tapping temperature, pour the molten steel into the ladle, calm down for 1-2 minutes, and pour it into steel ingots. the

The anti-vibration bar alloy material is required to be pure; the chemical composition is accurate and uniform; and it has a specified organizational state. There are a number of indisputable advantages to using an induction hob. Because it has no pollution sources that exist in other equipment, it can guarantee the purest metal material for carbon and other impurities; it can ensure the uniformity of the alloy because of the electrodynamic stirring of the metal pool; it can ensure that the metal is accurately obtained and maintained The required temperature and the uniform distribution of temperature along the entire molten pool temperature; eliminate local overheating; because of its fast melting speed and less metal burning loss, it creates favorable conditions for accurately obtaining the specified alloy composition and the least element burning loss; in It is highly mobile when refining metals whose chemical composition differs from that of the forehearth. the

The forging: the ingot of the anti-vibration bar alloy material smelted by the induction furnace is heated and kept at 1150-1220°C and then forged into a steel billet with a size of 50*50mm; after the surface is finished and ground, it is sent to the next step of hot rolling blank process . the

Forging is a processing method that uses forging machinery to apply pressure to metal blanks to cause plastic deformation to obtain forgings with certain mechanical properties, certain shapes and sizes. Forging can eliminate defects such as loose casting of metals during the smelting process. , optimize the microstructure, and because the complete metal flow line is preserved, the mechanical properties of forgings are generally better than castings of the same material. For important parts with high loads and severe working conditions in related machinery, forgings are mostly used, except for plates, profiles or weldments that can be rolled with simpler shapes. Generally speaking, forging is the first step in material processing called "blank opening". the

The hot rolling: the anti-vibration bar alloy material 50×50mm blank is placed at a temperature of 1200±10° C., heated and kept warm, and then hot-rolled to form a 13×25mm rectangular bar. the

The anti-vibration bar alloy material is forged into a 50×50mm blank and rolled into steel products of various geometric cross-sectional shapes by means of heating. According to the shape of the steel section, it can be divided into three types: simple section, complex section or special-shaped section and periodic section. the

(1) Hot rolling can significantly reduce energy consumption and cost. The metal has high plasticity and low deformation resistance during hot rolling, which greatly reduces the energy consumption of metal deformation. the

(2) Hot rolling can improve the processing performance of metals and alloys, that is, the coarse grains in the cast state are broken, the cracks are significantly healed, the casting defects are reduced or eliminated, the cast structure is transformed into a refined deformed structure, and the processing of the alloy is improved. performance. the

(3) The anti-vibration bar alloy material is rolled with a large hot-rolled ingot and a large reduction, which not only improves the production efficiency, but also creates conditions for increasing the rolling speed and realizing the continuity and automation of the rolling process. the

(4) The hot rolling process actually belongs to the intermediate processing process and is an important step in forming the finished blank. the

The heat treatment includes: (1) solution treatment: lay the hot-rolled end cap material 13*25mm in a bell-type hydrogen protection furnace for solution treatment; (2) aging treatment: put the end cap material after solution treatment The bars are also placed in a hydrogen protection furnace for aging treatment. the

Solid solution treatment is to dissolve the carbides in the matrix and γ' to be equal to obtain a uniform supersaturated solid solution, which facilitates the re-precipitation of fine, uniformly distributed carbides and γ' and other strengthening phases during aging, and at the same time eliminates due to hot and cold processing. Stress causes the alloy to recrystallize. Secondly, the solution treatment is to obtain a suitable grain size to ensure the high temperature creep resistance of the alloy. The temperature range of solid solution treatment is about 980~1250℃, which is mainly selected according to the phase precipitation and dissolution rules in each alloy and the use requirements to ensure the necessary precipitation conditions and a certain grain size of the main strengthening phase. For alloys used at high temperature for a long time, better high temperature durability and creep properties are required, and a higher solution temperature should be selected to obtain a larger grain size; for medium temperature use, better room temperature hardness, yield strength, For alloys with tensile strength, impact toughness and fatigue strength, a lower solution temperature can be used to ensure a smaller grain size. During high-temperature solution treatment, various precipitated phases are gradually dissolved, and at the same time, the grains grow; during low-temperature solution treatment, not only the main strengthening phase dissolves, but also some phases may precipitate. For alloys with low supersaturation, a faster cooling rate is usually selected; for alloys with high supersaturation, cooling in air is usually used. the

Aging treatment refers to the heat treatment process in which the alloy workpiece is subjected to solution treatment, cold plastic deformation or casting, and after forging, it is placed at a higher temperature or at room temperature to maintain its performance, shape, and size over time. If the aging treatment process of heating the workpiece to a higher temperature and aging treatment for a shorter period of time is adopted, it is called artificial aging treatment. If the aging phenomenon occurs when the workpiece is placed at room temperature or under natural conditions for a long time, it is called natural aging treatment. aging treatment. The third method is that vibration aging has gradually entered the practical stage since the early 1980s. Vibration aging treatment uses vibration at a certain frequency to release the internal stress without heating and is not as time-consuming as natural aging. In order to achieve the purpose of timeliness. The purpose of aging treatment is to eliminate the internal stress of the workpiece, stabilize the structure and size, and improve the mechanical properties. the

In material production, in order to stabilize the size of castings, castings are often placed at room temperature for a long time before cutting. This measure is also known as statute of limitations. But this aging does not belong to the metal heat treatment process. the

The end cap turning process: the 13*25mm material after aging treatment is turned into an end cap of required size. the

Technical effects of the present invention: The anti-vibration bar assembly of the steam generator of the CAP1400 unit according to the present invention includes: an anti-vibration bar with a V-shaped structure and two end caps respectively arranged at both ends of the anti-vibration bar. The anti-vibration bar is made of 405 stainless steel; the end cap is made of 690 nickel-based alloy to facilitate welding and fixing with the U-shaped tube in the steam generator of the CAP1400 nuclear power unit, and the U-shaped tube is also made of 690 nickel-based alloy. The end cap is upset and fixed on the anti-vibration bar to prevent the end cap from being pulled off during the assembly and welding process of the anti-vibration bar assembly and the U-shaped pipe. The above-mentioned anti-vibration bar assembly has a simple structure, and the product quality meets the precision requirements for the anti-vibration bar of a steam generator in a nuclear power plant, and is safer in use. The preparation method of the anti-vibration strip, through strict preparation procedures, ensures the technical requirements for the anti-vibration strip assembly of the steam generator in the nuclear power plant, ensures the quality, and improves the safety. The end cap is fixed on the anti-vibration strip by upsetting, so as to prevent the end cap from being pulled off during the assembly and welding process of the anti-vibration strip assembly and the U-shaped pipe. During specific implementation, the center of the end cap and the parts adjacent to the two ends of the end cap on the anti-vibration strip are crushed. the

Description of drawings

Fig. 1 is a schematic structural view of the anti-vibration bar assembly of the CAP1400 unit steam generator of the present invention, reference numerals: 1--anti-vibration bar, 2--end cap;

Fig. 2 is the top view of Fig. 1;

FIG. 3 is a cross-sectional view of the end cap in FIG. 1 , where 2-1 is a mounting hole. the

Detailed ways

Example 1

As shown in Figure 1, the preparation method of the anti-vibration bar assembly of the steam generator of the CAP1400 unit of this embodiment includes: preparation of the anti-vibration bar, preparation of the end cap, bending of the anti-vibration bar, and assembly of the end cap , Upsetting, inspection, cleaning and packaging processes. the

The anti-vibration bar is bent and formed: the anti-vibration bar is cut according to the total length of the required size plus 50mm allowance, the angle is set to bend the anti-vibration bar, and the bent anti-vibration bar is placed on a surface grinder Above, grind the thickened area of the corner to meet the requirements of the drawing. the

The end cap assembly: use alcohol to gently scrub the surface of the end cap and the inner hole formed by wire cutting for the end cap produced according to the end cap production method, and clean the stainless steel bar with alcohol at the same time. After cleaning, remove the burrs , bite marks, protruding metal or sharp corners; then insert the stainless steel rod into the cap end and align the angle for assembly. the

The upsetting pressure includes: (1) Pull-off force process evaluation: evaluate the pull-off force of the end cap after assembly and upsetting, so that the position of the sleeve cap does not move under the minimum pulling force of 4448N; Make a record of the pull-off force of the end cap, select the most suitable pressure as the pressure process parameter in the upsetting process; (2) Upsetting pressure: put the end of the cap into the upsetting mold, and use a hydraulic press to align the central position of the end cap respectively And the position on the anti-vibration bar adjacent to the two ends of the end cap is upsetting. After pressing down and positioning, keep the pressure for 10 seconds and then unload to ensure that the cap end meets the requirements of the drawing after upsetting. There are four upsetting positions on the anti-vibration strip, two adjacent to the end of the end cap, which are used to limit the end of the cap and prevent the displacement of the end cap on the anti-vibration strip. the

The inspection: (1) Flatness inspection, measure with feeler gauge on the inspection platform; (2) Dimension inspection, use digital display micrometer to measure the product; (3) Angle inspection, use digital display angle measuring instrument to measure; (4) Visual inspection, visual inspection of workpieces one by one to ensure that there are no defects on the surface, and the surface roughness is measured by crawling with a roughness measuring instrument; (5) Surface roughness measurement is measured with a roughness detector or a comparison sample; All dimensional inspection results shall comply with the drawing requirements. the

Said cleaning: clean the bar according to the relevant regulations to ensure that the surface of the finished product is free from rust, dust and other pollutants, (1) sulfur, lead, mercury, cadmium and other metals with low melting points, as well as their alloys and compounds, containing Halogen substances are prohibited from being used in the preparation, testing, inspection and packaging of anti-vibration strips; (2) lubricants, cutting fluids and cleaning agents do not contain the above substances; molybdenum disulfide lubricants, polytetrachlorethylene and other Polyfluorinated materials are also prohibited. the

Example 2

The preparation method of the anti-vibration bar in the above-mentioned embodiment 1 includes the following steps in sequence: induction furnace smelting, smelting analysis, forging, hot rolling, first heat treatment, performance test (tensile, hardness) and metallographic inspection, product Analysis, cold drawing, second heat treatment, cold working, property testing (tensile, hardness) and grain size inspection, dimensional inspection, marking, cleaning, reporting. the

a. Induction furnace smelting: when alloy materials are smelted, nickel plates, pure iron, and metal chromium are placed at the bottom of the induction furnace to be densely packed. After melting 70%, 2% of the total slag is added for steelmaking, and the temperature of molten steel is measured. After reaching the tapping temperature, pour the molten steel into the ladle, calm down for 1-2 minutes, and pour it into steel ingots and bars. The weight of each ingot is 40-50kg, and the diameter of the steel ingot is 140mm for the small end and 155mm for the large end. the

b. Smelting analysis: (1) Sampling: take a chemical analysis sample by turning or planing outside the range of 20mm from the ingot head and ingot tail; (2) Take a chemical analysis sample for each furnace number to determine the chemical composition of each furnace steel, and press Content standard data were screened. The melting chemical composition should meet the requirements of the following table:

c. Forging: Forge the steel ingots that pass the analysis at 1150-1220°C into billets with a size of 50*50mm;

(1) Forging heating thermometer:

(2) Forging: forging compression ratio: 4-6; forging size: 50*50mm; billet big head cut off more than 100mm, small head cut off more than 50mm; Surface defects such as heavy skin. the

d. Hot rolling: put the steel billet at a temperature of 1050-1100 ℃ for hot rolling, and roll it into a bar of ф16mm. After hot rolling and cooling, check the surface quality of cracks, folds, scars, and inclusions one by one, and thoroughly polish them clean;

(1) Billet heating temperature table is as follows:

(2) Rolling: The adjustment worker should straighten the appearance of the rolled product, and roll it into a ф16mm wire; after the rolled product is cooled, it is necessary to check the surface quality of cracks, folds, scars, and inclusions one by one, and thoroughly polish it. ;Rolling ratio: ≥5. the

e. The first heat treatment: Vacuum annealing treatment is carried out on the hot-rolled bar, the temperature is kept at about 800°C, and the temperature deviation during the annealing and heat preservation period does not exceed 10°C; the annealing temperature is:

f. Performance test: (1) Randomly take a group of samples for each batch number of the hot-rolled bars after heat treatment; (2) Conduct tensile test, hardness test, metallographic analysis and product analysis on the samples respectively. Qualified products are excluded;

1. The tensile test results should meet the requirements of the following table:

performance room temperature 350°C Specified strength Rp0.2(Mpa) ≥170 ≥145 Tensile strength Rm(Mpa) ≥415 ≥370 Elongation after break A (%) ≥20 info Reduction of area Z (%) ≥45 info

When the bar is ≤25mm, the longitudinal axis of the sample is consistent with the center of the bar, and the distance between the useful part of the sample and the heat-treated end of the bar must not be less than the diameter of the bar. the

2. Hardness test should meet:

performance room temperature Hardness (HB) ≤207

The hardness test shall check the hardness of the bar at the middle part of the distance from the center of the bar to the surface. the

3. Metallographic analysis should meet:

4. Product analysis: samples are taken from both ends of the tensile sample for material product analysis, and the analysis results should comply with:

5. Retest and reheat treatment:

5.1 If the tensile test results of the bar do not meet the requirements, two additional samples can be cut from the adjacent parts of the unqualified sample for tensile test, and the acceptance can only be accepted when the test results of the two additional samples meet the requirements;

5.2 If the mechanical properties of any batch of rods are unqualified due to improper heat treatment, the batch of materials can be re-heat treated, but the number of re-heat treatments should not exceed two times; Inspection (except inspection of chemical composition and non-metallic inclusions); all inspections shall meet the requirements of this technical condition. the

g. Cold drawing: (1) softening and annealing treatment first, and heat preservation at 720-750°C for 40 minutes; (2) drawing in sequence with polycrystalline molds according to deformation requirements, and grinding and repairing micro-cracks on the surface. After grinding until there is no defect, the next drawing can be carried out. the

The drawing deformation during cold drawing is φ16→φ14→φ12.5→φ11→4.8×12.8→4.4×12.5→4.028×12.19. the

The softening annealing treatment system is as follows:

h. Second heat treatment: Lay the finished material in a bell-type heat treatment furnace, and conduct heat treatment under hydrogen protection. The temperature deviation during annealing and heat preservation should not exceed ±10°C. The heat treatment temperature and other requirements are as follows. conduct:

i. Finished product processing: Straightening, polishing and other cold processing procedures are carried out on the heat-treated bar. The thickness, width, twist, straightness and other dimensions after processing should meet the requirements of the following table:

j. Performance test: Carry out mechanical property test, hardness test and grain size test on the bar, and exclude the bar that does not meet the technical requirements. the

1. The mechanical performance test shall comply with:

performance room temperature Specified strength Rp0.2(Mpa) 240-550 Tensile strength Rm(Mpa) 415-585 Elongation after break A (%) ≥15

2. Hardness test should meet:

performance room temperature Hardness HB≤207 or HRB≤93

3. Grain size inspection:

Testing method level requirements ASTM E112 Grade 5 or finer

If the mechanical properties of the bar do not meet the technical requirements, double samples can be taken from the adjacent part of the sample for retesting, and the retesting results should meet the technical requirements. the

k. Dimensional inspection: (1) Visual inspection: visually inspect the surface of each material one by one, and require no cracks, scratches and other defects. No welding repair is allowed for the bars, and the surface roughness is checked one by one. Inspection, additional inspection is required for suspicious areas, and the measured result should be Ra≤1.6μm; (2) Size inspection: 5% of the material is sampled for size inspection to ensure that the material size meets the tolerance requirements of 4.028±0.013*(12.19). the

l. Marking: Each material should be accurately marked or labeled, indicating the name of the manufacturer, material grade and specification; melting furnace number, batch number and part number; contract number or order number. the

m. Cleaning: Clean the bar according to the relevant regulations to ensure that the surface of the finished bar is free from rust, dust and other pollutants; the steel bar cannot touch materials that are harmful to it and its integrity. The main metal incompatible materials are lead, zinc, copper, aluminum, cadmium, tin, mercury, sulfur, arsenic, boron and general low melting point alloys and their compounds. Fluorides, sulfates, chlorides, and acidic chlorides from degradation are a potential hazard, and tapes, markers, couplants, penetrants, and coatings should be chosen carefully; if abrasive tools are to be used, ensure that the abrasive tools Not polluted. the

Example 3

The preparation method of the end cap in the above-mentioned embodiment 1 includes the following steps in sequence: intermediate frequency induction furnace smelting, electroslag refining, smelting analysis, forging, ultrasonic inspection, hot rolling, heat treatment, performance test, product analysis, end cap car processing, size Inspect, mark, clean. the

a. Induction furnace smelting: when alloy materials are smelted, nickel plates, pure iron, and metal chromium are placed at the bottom of the induction furnace to be densely packed. After melting 70%, 2% of the total slag is added for steelmaking, and the temperature of molten steel is measured. After reaching the tapping temperature, pour the molten steel into the ladle, calm down for 1-2 minutes, and pour it into steel ingots and bars. The weight of each ingot is 40-50kg. the

b. Electroslag refining: After the alloy material is smelted, electroslag refining is required to effectively improve the purity and uniformity of the alloy steel, improve the surface and internal quality of the steel ingot, and improve the performance of the alloy steel. When the electroslag refining is completed, feed shrinkage. After feeding for 3-5 minutes, cool for more than 3 minutes and take off the ingot. Then carry out electroslag ingot surface treatment: surface peeling and grinding. the

c. Smelting analysis: After the steel ingot is cooled, samples are taken on the steel ingot for chemical analysis of chemical elements. (1) Sampling: take a chemical analysis sample by turning or planing outside the range of 20mm from the ingot head and ingot tail; (2) Take a chemical analysis sample for each furnace number, according to "ASTM E38 Nickel-Chromium and Nickel-Chromium-Fe Alloy Chemistry Analyze the chemical composition of the material according to the test method required by "Analysis Method", and screen according to the content standard data. The melting chemistry should meet:

d. Forging: Forge the steel ingots that pass the analysis at a temperature of 1240-1260°C to form a billet with a size of 50*50mm. the

1. Before forging, the steel ingot should be annealed, and the heat treatment temperature should be as follows:

2. Deformation process: forging compression ratio: 4-6; billet big head cut off more than 100mm, small head cut off more than 50mm; forged billet size is 50*50mm; Surface defects such as wrinkles, cracks and heavy skin. the

e. Ultrasonic inspection: Ultrasonic inspection is carried out on the peeled and ground square bar according to the testing method and acceptance criteria stipulated in the "Technical Conditions for Non-destructive Testing of Bars". the

f. Hot rolling: place the billet at a temperature of about 1200°C for hot rolling, and roll it into a material of 13*25mm. The deviation of the hot rolling temperature does not exceed 10 degrees. Defects such as folds, scars, inclusions, etc., and thoroughly polished;

1. The forged billet is annealed before hot rolling, and the annealing temperature is as follows:

2. Rolling control: Roll the end cap material to 13*25mm; after the rolled products are cooled, inspect the surface cracks, folds, scars, inclusions and other defects one by one, and cut off or thoroughly polish them; the rolling ratio is ≥5. the

g. Heat treatment: 1. Solution treatment: lay the hot-rolled end cap material 13*25mm flat in a bell-type hydrogen protection furnace for solution treatment, and the heat treatment temperature is as follows:

Carbon contentwt.% Minimum holding temperature ℃ 0.015 1016 0.016 1023 0.017 1030 0.018 1036 0.019 1043 0.020 1049 0.021 1055

[0130] 0.022 1060 0.023 1066 0.024 1071 0.025 1076 0.026 1081 0.027 1085 0.028 1090 0.029 1094 0.030 1099

Among them, the insulation temperature deviation does not exceed ±10°C. the

2. Aging treatment: The bars after solid solution treatment must be subjected to aging treatment, and the aging treatment should also be carried out in a hydrogen protection furnace. The heat treatment temperature is: 

Among them, the door temperature deviation during the aging treatment period should not exceed ±10°C. the

3. The solid solution and aging treatment records should be included in the quality certification documents, and the heat treatment records should include the holding temperature and its deviation, holding time, heating rate, heating atmosphere and cooling method. the

h. Performance test:

1. Sampling: Randomly take a sample for each heat batch number for mechanical performance test, the longitudinal axis of the tensile sample is parallel to the axial direction of the bar. The useful part of the tensile test piece is separated from the end of the bar by at least one bar diameter; the longitudinal axis of the tensile test piece is located at the center of the bar; the test piece has sufficient length to intercept the hardness test piece, Metallographic samples and all test quantities and samples required for possible retests. the

2. Tensile test should meet:

Among them, the tensile test uses a standard sample with a gauge length of 50 mm and a diameter of 12.5 mm. the

3. Metallographic analysis: Take a sample near the sample of the tensile test for metallographic analysis. The detection standard of metallographic analysis is:

4. Macroscopic erosion test: One piece of each batch is selected for macroscopic erosion test. The test should be carried out on the cross-section of the cut head at both ends of the bar, and evaluated with the naked eye or with a magnifying glass below 10 times. No shrinkage cavity, Defects such as voids, cracks, slag inclusions and pinholes. the

5. Intergranular corrosion test: For each batch of bars, a group (two) samples should be taken from any bar after aging treatment for intergranular corrosion test. After sensitization treatment, the sensitization treatment system is 675°C±5°C for 1 hour, and the corrosion rate of the sample should be less than 20mdd (mg/square decimeter.day). the

6. Product analysis: Take a sample from each furnace near the tensile sample for product analysis of the material, and the product analysis results should meet: 

i. End cap turning processing: Carry out performance test on the 13*25mm material after aging treatment, and turn the qualified material into end cap products with a diameter of 22.86±0.05 and a length of 50.8±0.07 as required. the

j. Dimensional inspection: 1. Visually inspect the surface of each material one by one, and the end caps are not allowed to have nicks, burrs, longitudinal cracks, and metal bulges. 2. Check the size of the material, and the inspection quantity of each furnace material should be greater than 5%. the

k. Marking: Each piece of material should be accurately marked or labeled, which should include: order number, material grade and specification, bar piece number, melting furnace number, heat treatment furnace number, and name of the bar manufacturer. the

l. Cleaning: Clean the bar according to the relevant regulations to ensure that the surface of the finished end cap is free from rust, dust and other pollutants. the

Claims (5)

1. the preparation method of the antivibration bar assembly of a nuclear power generating sets steam generator is characterized in that described antivibration bar assembly comprises: the antivibration bar of V-shape structure and be located at respectively the end cap at antivibration bar two ends; The cross section of antivibration bar is rectangular, and the cross section of end cap is three-back-shaped; Described antivibration bar is selected 405 stainless steel materials; Described end cap is selected 690 nickel-bass alloy materials;

Described preparation method comprises that antivibration bar bar bends the operation of moulding, it comprises: with antivibration bar bar on request the size overall length add the 50mm allowance and cut off, set angle bends the antivibration bar, and the antivibration bar after bending places on the surface grinding machine, and the bent angle buildup area is carried out reconditioning.

2. the preparation method of antivibration bar assembly according to claim 1, characterized by further comprising: the operation of end cap assembling, it comprises: end cap is dabbed with alcohol wash end cap surface and line cutting endoporus, with alcohol stainless steel bars is cleaned simultaneously, after cleaning up, deburring, bite mark, protrusion metal or wedge angle; Again the cap end is inserted in the end of stainless steel bar, alignment angle is assembled.

3. the preparation method of antivibration bar assembly according to claim 2, characterized by further comprising the operation of upsetting pressure, it comprises: the cap end is put into the upsetting pressure mould, respectively the part at the middle position of end cap and the contiguous end cap two ends on the antivibration bar is carried out upsetting pressure with hydraulic press, depress maintenance pressure off-load after 10 seconds behind the location.

4. the preparation method of an antivibration bar bar claimed in claim 1 is characterized in that comprising successively following operation: induction furnace smelting, forging, hot rolling, the first heat treatment, cold-drawn, the second heat treatment, finished product processing;

Described induction furnace is smelted: place nickel plate, pure iron, crome metal in the induction furnace bottom when alloy material is smelted, and load in mixture closely knit, after the fusing 70%, 2% the slag charge that adds the weight that always feeds intake is made steel, record molten steel temperature and reach after the tapping temperature molten steel is fallen down in the ladle, pour into steel ingot after calm 1-2 minute;

Described forging: the steel ingot of the antivibration bar alloy material after will smelting by induction furnace is forged into the steel billet of 50*50mm size after 1150-1220 ℃ of heating and insulation, and effects on surface finishing reconditioning;

Described hot rolling: with antivibration bar alloy material 50 * 50mm blank, carry out hot rolling after placing under the 1050-1100 ℃ of temperature heating, insulation, be rolled into the bar of ф 16mm;

Described the first heat treatment: the bar after the hot rolling is carried out carrying out after surface finish, the reconditioning vacuum annealing again process, φ 16 antivibration bar alloy material bars heat, are incubated under 800 ℃ ± 10 ℃ of temperature;

Described cold-drawn: carry out first soft annealing and process, insulation is 40 minutes under 720-750 ℃ of temperature; With glomerocryst mould successively drawing, and effects on surface micro-crack place carries out reconditioning by deformation requirements, and reconditioning can be carried out the drawing of lower road to zero defect;

Described the second heat treatment: the material that antivibration bar alloy bar is pulled to finished product is tiled in the bell-jar heat-treatment furnace, under the hydrogen shield state, heat-treat, temperature is 788-815 ℃ between the annealing soak, insulation is more than 3 hours, then, slowly cool to below 610 ℃ with the cooling velocity that is no more than 28 ℃/hour, air cooling is to room temperature again;

Described finished product processing: the bar after processing is aligned, polished.

5. the preparation method of an end cap claimed in claim 1 is characterized in that comprising successively following operation: induction furnace smelting, forging, hot rolling, heat treatment, end cap Vehicle Processing;

Described induction furnace is smelted: place nickel plate, pure iron, crome metal in the induction furnace bottom when alloy material is smelted, and load in mixture closely knit, after the fusing 70%, 2% the slag charge that adds the weight that always feeds intake is made steel, record molten steel temperature and reach after the tapping temperature molten steel is fallen down in the ladle, pour into steel ingot after calm 1-2 minute;

Described forging: the steel ingot of the antivibration bar alloy material after will smelting by induction furnace is forged into the steel billet of 50*50mm size after 1150-1220 ℃ of heating and insulation, and effects on surface finishing reconditioning;

Described hot rolling: with antivibration bar alloy material 50 * 50mm blank, carry out hot rolling after placing under 1200 ± 10 ℃ of temperature heating, insulation, be rolled into the rectangular bar of 13 * 25mm;

Described heat treatment successively comprises: (1) solution treatment: the end cap material 13*25mm material after the hot rolling is tiled in solution treatment in the bell-jar hydrogen protection stove; (2) Ageing Treatment: also place the hydrogen shield stove to carry out Ageing Treatment the bar after the solution treatment;

Described end cap Vehicle Processing: the 13*25mm material after the Ageing Treatment is machined, be processed into the end cap of required size.

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