CN104972052A - Forging method for pipe nozzle bosses of nuclear power main pipeline blank - Google Patents

Abstract

The invention discloses a forging method for pipe nozzle bosses of a nuclear power main pipeline blank. The two radial pipe nozzle bosses distributed in the axial direction are arranged on the nuclear power main pipeline blank and are arranged on the circumferential face of the pipeline blank in a staggered mode, a certain included angle is formed between the two pipe nozzle bosses, and the pipe nozzle bosses are formed through the die forging process. The forging method is characterized by comprising the following steps that (1), prototype pipe nozzle bosses are forged through a conventional die forging method; and (2), the pipe nozzle bosses are further forged through a backward extrusion die forging method, pipe nozzle inner holes are formed through hot punching, the boss forming deformation is enlarged, and the contours of the bosses are quickly plumped, so that the frequency and time of repeated heating are reduced, thick grains of materials are avoided, and the percent of pass of forged pieces is improved.

Description

The forging method of main nuclear power pipeline blank ozzle boss

Technical field

The invention belongs to nuclear power generating equipment process technology, relate to the forging method of main nuclear power pipeline blank, particularly relate to main nuclear power pipeline blank ozzle boss forming method.

Background technology

In the face of the severe situation of current global energy, exploitation nuclear energy is made to become the current important channel solving energy problem.AP1000 compressed water reactor nuclear power technology is the third generation large nuclear-power type of US Westinghouse company's design, is the state-of-the-art nuclear power generating equipment in the current world.Its main feature reaches 60 years service life, and single apparatus for piling and filling capacity reaches 1,250,000 kilowatts.Main pipeline is one of the key equipment in core cover, is the large thick-wall bearing pipe of coupled reaction core pressure vessel and steam generator, is called as " sustainer " of nuclear power station.

See Fig. 1, the radial ozzle that this main pipeline has two to distribute vertically, two ozzles are in a certain angle on pipeline side face.For making ozzle have enough wall thickness, meet requirement of strength, the outline of ozzle is designed to boss structure.

The manufacturing process of this pipeline is, first forges pipeline blank, then carries out machining, comprise turning, boring centre bore, milling ozzle endoporus.

Material for the manufacture of this pipeline is ultra-low carbon austenitic stainless steel, and this material is without allotropic transformation, and metallographic structure and the performance of workpiece depend primarily on Forging Technology.Forging Major Difficulties is the shaping of two ozzle boss, the deflection once heating forging and stamping is inadequate, often need repeated multiple times heating to forge and press, just boss profile can be made to fill type full, problem is, the heating for multiple times cumulative time is very long, can cause the coarse grains of material, mechanical property is defective, therefore forging percent defective is higher, economic loss is huge, becomes problem demanding prompt solution.

Summary of the invention

For above problem, the invention provides a kind of forging method of backward extrusion of main nuclear power pipeline rough forging ozzle.Use the method forging main nuclear power pipeline, the deflection of ozzle boss forming process can be strengthened, make boss profile rapid shaping, thus reduce the number of times and time that repeatedly heat, avoid the material grains of mouthpiece portion thick.Its technical solution is:

A kind of forging method of main nuclear power pipeline blank ozzle boss, the radial ozzle boss that described main nuclear power pipeline blank has two to distribute vertically, two ozzle boss interlaced arrangement on pipeline blank side face, in a certain angle, with contour forging technique this ozzle boss shaping; The method comprises the steps:

(1), first die forging method forges the blank of ozzle boss routinely;

(2) use the further forged tube nozzle boss of backward extrusion die forging method, again, hot washing pipe mouth endoporus, strengthen boss forming deflection, make boss profile full fast, thus reduce the number of times and time that repeatedly heat, avoid material grains thick.

The concrete steps of described backward extrusion die forging method are:

(1), manufacture a set of forging and stamping punching die, this mould is made up of drift, counterdie, and described counterdie has ozzle boss mounting groove and locating piece;

(2), by drift be arranged on the pressure head of hydraulic press, counterdie be fixed on the workbench of hydraulic press, corresponding with drift; The ozzle boss of pipe is put into counterdie mounting groove, and is located by locating piece;

(3), start hydraulic press, drift is compressed into ozzle boss, make boss profile full fast.

Described drift is circular cone post drift, and its maximum gauge is less than the ozzle diameter of bore of finished product main nuclear power pipeline.

Beneficial effect of the present invention:

Hot washing pipe mouth endoporus in forging process, utilizes punching deflection to increase ozzle boss forming deflection, makes boss profile full fast, thus reduce the number of times and time that repeatedly heat, avoid material grains thick, drastically increase forging qualification rate, economic effect highly significant.

Accompanying drawing explanation

Fig. 1 is the structure chart of finished product main nuclear power pipeline

Fig. 2 is the sectional view of Fig. 1

Fig. 3 is the punch structure schematic diagram of punching die

Fig. 4 is the lower die structure schematic diagram of punching die

Number in the figure represents: 1: drift, 1-2: drift root, 1-1: drift body, 2: counterdie, 2-1: die holder, 2-2: die body, 2-3: drift pilot hole, 2-4: ozzle boss mounting groove, 2-5: locating piece, 3: ozzle.

Detailed description of the invention

First manufacture forge die, comprise a set of common die and a set of punching die.

The die cavity of described common die is consistent with the profile of ozzle boss.

See Fig. 2, Fig. 3, Fig. 4, described punching die is made up of drift 1, counterdie 2.

Described drift 1 has drift body 1-1, drift root 1-2, the shape of drift body 1-1 is circular cone post, its maximum gauge is less than the ozzle diameter of bore of finished product main nuclear power pipeline, and for postorder processing ozzle endoporus reserves allowance, drift root 1-2 is used for being connected with hydraulic press pressure head.

Described counterdie 2 has die holder 2-1, die body 2-2; Die body 2-2 has drift guide hole 2-3, this drift guide hole 2-3 is conical bore, and its tapering is consistent with the tapering of drift body 1-1; Space formation ozzle boss mounting groove 2-4 between die holder 2-1, die body 2-2, the profile of this mounting groove 2-4 are consistent with the profile of ozzle boss; Die holder 2-1 is provided with locating slot, and groove is built with locating piece 2-5.

The forging step of ozzle boss is as follows:

1, the blank of ozzle boss is forged and pressed out with common die;

2, use the further forged tube nozzle boss of backward extrusion die forging method again, hot washing pipe mouth endoporus, step is:

(1), by drift be arranged on the pressure head of hydraulic press, counterdie be fixed on the workbench of hydraulic press, corresponding with drift, pre-hot die before punching;

(2), by after heating of pipe blank, its ozzle boss is put into counterdie mounting groove, and is located by locating piece;

(3), hydraulic press is started, drift is compressed into ozzle boss, to the backward extrusion that boss carries out from inside to outside, punching deflection is utilized to make boss profile full fast, in the process, drift puts in the guide hole on punch die, until fit with guide hole, ozzle boss is gone out a horn-like blind hole.

Claims (3)

1. the forging method of a main nuclear power pipeline blank ozzle boss, the radial ozzle boss that described main nuclear power pipeline blank has two to distribute vertically, two ozzle boss interlaced arrangement on pipeline blank side face, in a certain angle, with contour forging technique this ozzle boss shaping; It is characterized in that, the method comprises the steps:

(1), first die forging method forges the blank of ozzle boss routinely;

(2) use the further forged tube nozzle boss of backward extrusion die forging method, again, hot washing pipe mouth endoporus, strengthen boss forming deflection, make boss profile full fast, thus reduce the number of times and time that repeatedly heat, avoid material grains thick.

2. the method for claim 1, is characterized in that, the concrete steps of described backward extrusion die forging method are:

(1), manufacture a set of forging and stamping punching die, this mould is made up of drift, counterdie, and described counterdie has ozzle boss mounting groove and locating piece;

(2), by drift be arranged on the pressure head of hydraulic press, counterdie be fixed on the workbench of hydraulic press, corresponding with drift; The ozzle boss of pipe is put into counterdie mounting groove, and is located by locating piece;

(3), start hydraulic press, drift is compressed into ozzle boss, make boss profile full fast.

3. method as claimed in claim 2, it is characterized in that, described drift is circular cone post drift, and its maximum gauge is less than the ozzle diameter of bore of finished product main nuclear power pipeline.