CN104624892B

CN104624892B - A kind of method refining AP1000 Nuclear power plant main pipeline forging ozzle position crystal grain

Info

Publication number: CN104624892B
Application number: CN201510062472.4A
Authority: CN
Inventors: 杨滨; 王胜龙; 王西涛
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2015-02-05
Filing date: 2015-02-05
Publication date: 2016-08-24
Anticipated expiration: 2035-02-05
Also published as: CN104624892A

Abstract

The present invention relates to a kind of method refining AP1000 Nuclear power plant main pipeline forging ozzle position crystal grain, belong to rustless steel abnormal shape steel billet solid forging grain refining and control technical field.First by steel billet preforming, it is octagon that the forging geomery after preforming meets cross section, and main paragraph part octagon height is 980 1050mm, and reserved boss position octagon height is more than 1480mm so that it is have enough deflections to carry out forged tube nozzle.The most in different directions it is depressed to a certain degree, obtain net shape size finally by machining.It is an advantage of the current invention that to reduce forging times, improve forging efficiency, both met the size at main pipeline boss position, and reached again the requirement of more than 2 grades targets of grain size.

Description

A kind of method refining AP1000 Nuclear power plant main pipeline forging ozzle position crystal grain

Technical field

The invention belongs to rustless steel abnormal shape steel billet solid forging grain refining and control technical field, be specifically related to a kind of thin The method changing AP1000 pressurized-water reactor nuclear power plant primary Ioops main pipeline forging ozzle position crystal grain.

Background technology

Nuclear power is the clean energy resource of a kind of technology maturation, compared with thermoelectricity, nuclear power do not discharge sulfur dioxide, flue dust, Nitrogen oxides and carbon dioxide.With nuclear power Substitute For Partial coal electricity, it is the effective way of power industry pollutant emission reduction, Also it is the important measures slowing down global greenhouse effect.Although nuclear power developing is brought necessarily by Fukushima, Japan Nuclear Power Accident Impact, but from the point of view of long term growth, remain at China's nuclear power and solve power supply shortage and carbon dioxide simultaneously Reducing discharging the Main Means of two large problems, other regenerative resources such as wind energy, solar energy also need to regular hour solution Certainly efficiency, cost, the problem such as grid-connected.But meanwhile, Fukushima accident also warns us more to pay attention to Nuclear Safety Problem, Generation Ⅲ has carried out revolutionary improvement in terms of safety, has improve nuclear power station comprehensively Overall security, particularly AP1000 heap-type takes non-passive safety system, compared with conventional pressurized water heap, more Add safety, simple, effectively, be world market existing the safest, most advanced, through the nuclear power station of checking, Its reactor core damage probability only has 2.5 × 10^-7, therefore China has introduced a complete set of AP1000 skill from US Westinghouse company Art, and using the main force's heap-type as following Construction of Nuclear Electricity, on the basis of AP1000, develop China autonomous simultaneously CAP1400 and CAP1700 heap-type.Country's " nuclear power Long-and Medium-term Development planning (2005～2020) " points out: To the year two thousand twenty, nuclear power runs installed capacity and strives for reaching 40,000,000 kilowatts, and nuclear power annual electricity generating capacity reaches 2600-2800 hundred million kilowatt hour.Simultaneously, it is considered to the follow-up developments of nuclear power, the year two thousand twenty end should be protected building nuclear power capacity Hold about 18,000,000 kilowatts.According to the plan of country's Construction of Nuclear Electricity, absorb in the technological assimilation of generation Ⅲ nuclear power station After completing, the new nuclear power station of China will all use three generation techniques, the most from now on to before the year two thousand twenty Newly-increased nuclear power station in will have about half employing three generations's nuclear power technology.

Main pipeline is nuclear island nuclear safety I level Grand Equipments.Due to the most only design of AP1000 technology, I State is that drawing lands first, and its main pipeline have employed again innovationization design in addition, and can main pipeline be successfully prepared directly Connect and be related to AP1000 demonstration project and can build smoothly.In order to improve nuclear plant safety, reliability, can Maintainability, AP1000 main pipeline uses 316LN Ultra-low carbon control nitrogen stainless steel solid forging to make shaping, does not permits Permitted to be welded.And the main pipe hot leg pipe finished product external diameter of manufacture difficulty maximum reaches Φ 956mm, wall thickness reaches 85mm, crooked position angle 56.4 °, little curvature bending radius 1.5D0 and elbow two ends are with the longest straight Pipeline section, also with two branch pipe with heavy caliber ozzles (Φ 457 × 45) on elbow body, launches total length about 6m. The making experience of such pipe fitting is not also had to use for reference both at home and abroad at present.Meanwhile, the 316LN that this main pipeline uses Ultra-low carbon control nitrogen stainless steel forging temperature interval is narrow, heating-up temperature requires that height, resistance of deformation are big, in forging process Easily cracking.The shape of main pipeline and the feature of material so that the difficulty of forging is the highest, be known as in the industry Be current world nuclear main pipeline manufacture difficulty.Two ozzle indexing should be ensured accurately in forging process, Ensure the distance between two ozzles again, the most also to take into account the shape and size of whole forging.During due to forging Between long, fiery time many, high-temperature heating repeatedly, add the difficulty of crystal grain thinning.Accordingly, it would be desirable to optimize supervisor Road Forging Technology, reduces forging times, with crystal grain thinning to greatest extent.

AP1000 primary Ioops main pipe hot leg molding mode is large-scale hydraulic press solid forging molding at present, domestic The Forging Technology that producer uses mostly is: heating bar hold jumping-up repeatedly pulling pressure shoulder sub-material segmentation is pulled out Long.The main body pipeline section of pipeline is relatively simple due to shape, uses open die forging to be easier to reach geomery and crystal grain Degree requirement.But due to the existence of two mutual ozzles at 45 °, meeting during pressure shoulder sub-material and segmentation pulling Reserve two boss, and the two boss often occurs the problem of coarse grains in forging process, crystal grain Degree often only about 1 grade, does not reaches the target of main pipeline 2 grades of requirements above of entirety grain size.

Summary of the invention

316LN rustless steel room temperature undertissue is single austenite.Due to during heat treatment without phase transformation, therefore cannot Crystal grain thinning by the way of heat treatment, can only smash by the way of crystal grain brings it about recrystallization by plastic deformation Crystal grain thinning, this makes the crystal grain refining boss position extremely difficult.The technical problem to be solved in the present invention is to carry For a kind of Forging Technology for AP1000 main pipe hot leg forging boss position, use rational process route Produce the workpiece meeting forging geomery the requirement ensureing more than 2 grades grain sizes.

The material of steel ingot is 316LN Ultra-low carbon control nitrogen austenitic stainless steel, uses the tonnage water more than 8000 tons Press forges.The present invention comprises the following steps:

The first step, blank preform.Preformed forging can be pulled out by jumping-up repeatedly, press shoulder sub-material and segmentation to pull out Long acquisition.Preformed forging must is fulfilled for claimed below: cross section is octagon, positive eight limits of main paragraph part Shape height is 980-1050mm, and reserved boss position octagon height is more than 1480mm so that it is have enough Deflection carry out forged tube nozzle.

Second step, heating.The forging being preformed by is heated to 1100-1150 DEG C with stove, is incubated 3-4 hour.

3rd step, uses upper and lower flat anvil that forging carries out the first passage pressure, until the boss that forging contacts with lower anvil Part is concordant with main body pipeline section.

4th step, by the 3rd step gained forging half-twist counterclockwise, uses upper and lower flat anvil that forging is carried out second Secondary pressure, until forging is concordant with main body pipeline section with the projection section that lower anvil contacts.

5th step, rotates 45 ° counterclockwise by the 4th step gained forging or turns clockwise 135 °, using upper and lower flat anvil Forging is carried out the 3rd passage pressure, until forging is concordant with main body pipeline section with the projection section that lower anvil contacts.

6th step, by suitable for the 5th step gained forging/counterclockwise half-twist, makes boss position upwards, flat anvil in employing, Lower platform carries out four-pass pressure to forging, until height is 1480mm between upper flat anvil and lower platform.Forging Within making forging temperature remain at 900 DEG C～1150 DEG C during making.

7th step, forges another boss according to the technique of the 3rd step to the 6th step after forging is rotated 45 °.

8th step, after forging finished product, is positioned over ventilation, accelerates to be cooled to room temperature, to avoid crystal grain the longest Greatly.

9th step, machining.Boss position is machined out by the geomery required according to design, excises excess portion Point.

It is an advantage of the current invention that to reduce forging times, improve forging efficiency, both ensure that the shape at boss position Shape dimensional requirement, has reached again the requirement of more than 2 grades targets of grain size.

Accompanying drawing explanation

The invention will be further described with detailed description of the invention below in conjunction with the accompanying drawings:

Fig. 1 is the schematic diagram after steel ingot preforming,

Fig. 2 is the first passage pressure schematic diagram of forging,

Fig. 3 is the second passage pressure schematic diagram of forging,

Fig. 4 is the 3rd passage pressure schematic diagram of forging,

Fig. 5 is four-pass pressure schematic diagram (+Y direction) of forging,

Fig. 6 is four-pass pressure schematic diagram (+X direction) of forging,

Fig. 7 is that boss finish-forging part machines schematic diagram.

Detailed description of the invention

The first step, blank preform.Preformed forging is as it is shown in figure 1, can pull out by jumping-up repeatedly, press shoulder point Material and segmentation pulling obtain.Preformed forging must is fulfilled for claimed below: cross section is octagon, main body Section part octagon height is 980-1050mm, and reserved boss position octagon height is more than 1480mm, It is made to have enough deflections to carry out forged tube nozzle.

3rd step, as in figure 2 it is shown, use upper and lower flat anvil that forging carries out the first passage pressure, until forging with under The projection section of anvil contact is concordant with main body pipeline section.

4th step, as it is shown on figure 3, by the 3rd step gained forging half-twist counterclockwise, use upper and lower flat anvil to forging Part carries out the second passage pressure, until forging is concordant with main body pipeline section with the projection section that lower anvil contacts.

5th step, as shown in Figure 4, rotates 45 ° counterclockwise by the 4th step gained forging or turns clockwise 135 °, adopting With upper and lower flat anvil, forging is carried out the 3rd passage to depress, the projection section contacted with lower anvil until forging and main body Pipeline section is concordant.

6th step, as shown in Figure 5 and Figure 6, by suitable for the 5th step gained forging/counterclockwise half-twist, makes boss position Upwards, in employing, flat anvil, lower platform carry out four-pass pressure to forging, until between upper flat anvil and lower platform It is highly 1480mm.Within forging process making forging temperature remain at 900 DEG C～1150 DEG C.

9th step, machining.Boss position is machined out by the geomery required according to design, excises excess portion Point, as shown in Figure 7.

Claims

1. the method refining AP1000 Nuclear power plant main pipeline forging ozzle position crystal grain, it is characterised in that include Following steps:

The first step, blank preform: preformed forging is pulled out by jumping-up repeatedly, pressure takes on sub-material and segmentation Pulling obtains；

Second step, heating: the forging being preformed by is heated to 1100-1150 DEG C with stove, is incubated 3-4 hour；

3rd step, uses upper and lower flat anvil that forging carries out the first passage pressure, until what forging contacted with lower anvil Projection section is concordant with main tubular part；

4th step, by the 3rd step gained forging half-twist counterclockwise, uses upper and lower flat anvil that forging carries out Two passage pressures, until forging is concordant with main body pipeline section with the projection section that lower anvil contacts；

5th step, rotates 45 ° counterclockwise by the 4th step gained forging or turns clockwise 135 °, using upper and lower Flat anvil carries out the 3rd passage pressure to forging, until the projection section that forging contacts with lower anvil is put down with main body pipeline section Together；

6th step, by suitable for the 5th step gained forging/counterclockwise half-twist, makes boss position upwards, flat in employing Anvil, lower platform carry out four-pass pressure to forging, until height is 1480mm between upper flat anvil and lower platform, Within the scope of forging process making forging temperature remain at 900 DEG C～1150 DEG C；

7th step, is carried out another boss according to the technique of the 3rd step to the 6th step after forging is rotated 45 ° Forging；

8th step, after forging finished product, is positioned over ventilation, accelerates to be cooled to room temperature, to avoid crystal grain at high temperature Under grow up；

9th step, machining: boss position is machined out by the geomery required according to design, and excision is many Remaining part is divided；

Wherein implementing during the first step forging geomery after preforming, to meet cross section be octagon, main paragraph portion Dividing octagon height is 980-1050mm, and reserved boss position octagon height, more than 1480mm, makes It has enough deflections to carry out forged tube nozzle；

The material of steel ingot is 316LN Ultra-low carbon control nitrogen austenitic stainless steel, uses the tonnage water more than 8000 tons Press forges.