CN101169984B - Million-kilowatts-class nuclear power pressure container safe end manufacture process - Google Patents

Abstract

A manufacture process of safety end of a hermetical container for a million-kilowatt-class nuclear power station comprises the steps of selecting material, smelting, heating forged blank, forging, cooling the forged parts, and heating after forging. In the heating and forging process, the temperature holding time at the moderate temperature period is prolonged, the temperature rising time and thetemperature holding time at the high temperature period are reduced. During forging, the deformation amount of the forged part is increased from the second heating by an amount of 30-70 percent. The forging ratio is up to 8, the final forging temperature of the last heating is 850-780DEG C, and the deformation amount of the last heating is equal to or larger than 30 percent. After forging and shaping, the forged part is naturally cooled in the air and is melted. Each performance of the safety end of the hermetical container manufactured by the invention satisfies the requirement of RCC-M standard so as to ensure the use requirement of the safety end of million-kilowatt-class hermetical container, and to improve the safety and reliability.

Description

Million-kilowatts-class nuclear power pressure container safe end manufacture process

One, technical field:

The present invention relates to the manufacturing process of a kind of million kilowatt nuclear power station pressure vessel safety end, belong to core voltage force container control device and take over technical field.

Two, background technology:

The nuclear plant safety end is important, the key component of nuclear power plant reactor pressure vessel, and it is widely used in, and the nuclear power plant reactor pressure vessel is gone into, the discharge connection connecting portion, plays a part to ensure operate as normal, ensure its security performance.

It is very high that the safe end forging performance requires, and mainly is that grain size need greater than 3 grades to require, and the common process method can not meet the demands, and therefore nuclear power safe end forging can't domesticize at present, multidirectionally abroad orders.

Three, summary of the invention:

The purpose of this invention is to provide a kind of million-kilowatts-class nuclear power pressure container safe end workpiece comprehensive mechanical property height, crystal grain is tiny, serviceability is safe and reliable manufacturing process of making, overcome the deficiency of existing manufacturing technology, satisfy the nuclear plant pressure vessels demand.

Million-kilowatts-class nuclear power pressure container safe end workpiece blank of the present invention is of a size of: φ 890/ φ 650 * 350, and its manufacturing process comprises: select materials, the heating of melting, forging stock, forging are shaped, cooling and forge the after-baking operation, concrete steps and requirement are:

1) choose melting behind the starting material Z2CND18-12, get its chemical analysis of casting ladle sample test, adjust each micronutrient levels its percentage by weight is satisfied:

C≤0.035％，Mn≤2.0％，Si≤0.80％，P≤0.020％，S≤0.015％，?Ni11.50％-12.50％，Cr17.00％-18.20％，Mo2.25％-2.75％，Cu≤U.50％，N≤0.080％，B≤0.0010％，Co≤0.10％，Nb+Ta≤0.15％；

When 2) forging stock heating, forging stock are heated in 800～850 ℃ thermophase, be incubated 3 hours, the heating-up time that rises to 1200 ± 20 ℃ of hot stages is 2 hours, is incubated 1.5 hours;

3) forging is shaped, first fire time steel ingot ejection during forging, touch steel ingot with less deflection, make coarse grain, block etc. preliminary broken, second fire begins to increase the deflection of forging stock, and deflection is controlled at 30%～70%, vertical, horizontal upsetting pull forging stock 3～5 times, 6 center compactings of square forging stock 3～5 times repeatedly, forging ratio is reached more than 8, and the inferior final forging temperature of last fire is 850～780 ℃, last fire time deflection 〉=30%;

4) cooling and forging after-baking: forging is solid solution behind the natural cooling in air.

Adopt the grain size of the safe end forging of technology manufacturing of the present invention to reach more than 3 grades (containing 3 grades), every performance all satisfies RCC-M and ASTM standard-required, guaranteed the request for utilization of million kilowatt pressure vessel safety end, its security, reliability are greatly improved, satisfied the domestic technique demand.

Four, description of drawings (no accompanying drawing)

Five, embodiment

Below in conjunction with specific embodiment manufacturing process of the present invention is elaborated:

Million kilowatt nuclear power of the present invention station pressure vessel safety end workpiece blank is: φ 890/ φ 650 * 350, and manufacturing process and requirement are:

1) choose melting behind the high-quality raw material Z2CND18-12, get its chemical analysis of casting ladle sample test, by adjusting each micronutrient levels, actual measured value is shown in the following table with the required value contrast:

Z2CND18-12 chemical analysis (wt% percentage by weight)

?

C?

Mn?

Si?

P?

S?

Ni?

Cr?

Required value

≤ 0.035?

≤2.00?

≤0.80?

≤ 0.020?

≤ 0.015?

11.50～ 12.50?

17.00～ 18.20?

Measured value

0.024?

1.15?

0.70?

0.019?

0.008?

11.66?

17.04?

?

Mo?

Cu?

N?

B?

Co?

Nb+Ta?

?

Required value

2.25～ 2.75?

≤0.50?

≤ 0.080?

≤ 0.0010

≤0.10?

≤0.15?

?

Measured value

2.38?

0.15?

0.050?

0.0001?

0.037?

0.046?

?

?

?

?

?

?

?

?

?

Determine after the contrast to meet the demands.

2) forging stock heating: the temperature retention time of thermophase in the control in the heat temperature raising process, the intensification of hot stage and temperature retention time, specific requirement is: when being warming up in 800～850 ℃ thermophase, be incubated 3 hours, forging stock is heated evenly, and guarantees the thermoplasticity of the abundant heat penetration of forging stock heart portion, raising forging stock.Continue to be warming up to 1200 ± 20 ℃ of hot stages, this heating-up time is controlled to be 2 hours, is incubated 1.5 hours, does not produce defectives such as overheated, burning, crystal grain be thick to guarantee the safe end forging stock.

3) forging forming: first fire time steel ingot ejection during forging, touch steel ingot with less deflection, make thickization crystal grain, increase the deflection of forging stock since second fire, and deflection is controlled at 30%～70%, forging ratio reaches more than 8.Crystal grain is thick when avoiding crystallization again, and final forging temperature of last fire time is 800 ℃, and last fire time deflection 40% has tiny crystal grain to guarantee forging.

4) cooling of forging and forging after-baking: forging is heat-treated behind the natural cooling in air, and condition of heat treatment is solid solution.

After adopting technique scheme to make to finish, to workpiece test data shown in the following table

Tension test requires index and measured value

?	Rp 0.2(MPa)?	?R m(MPa)?	?A％(5d)?	Z％?
					The room temperature tensile index	≥220?	?≥520?	?≥40?	≥50?
Measured value	325?	?565?	?61?	77?

KV impulse test index and measured value

?	Minimum individual values is (J) laterally	Minimum individual values (J)
			20 ℃ of KV impulse tests	?≥60?	?≥100?
Measured value	?147?	?147?

This shows that every performance index of the million-kilowatts-class nuclear power pressure container safe end workpiece that makes by manufacturing process of the present invention all can satisfy RCC-M and ASTM standard-required.

Claims (1)

1. million-kilowatts-class nuclear power pressure container safe end manufacture process, this safe end workpiece blank is of a size of: φ 890/ φ 650 * 350, it is characterized in that: described safe end manufacturing process comprise select materials, the heating of melting, forging stock, forging are shaped, cooling and forge the after-baking operation, concrete steps and requirement are:

1) choose melting behind the starting material Z2CND18-12, get its chemical analysis of casting ladle sample test, adjust each micronutrient levels its percentage by weight is satisfied:

C≤0.035％，Mn≤2.0％，Si≤0.80％，P≤0.020％，S≤0.015％，Ni11.50％-12.50％，Cr17.00％-18.20％，Mo2.25％-2.75％，Cu≤0.50％，N≤0.080％，B≤0.0010％，Co≤0.10％，Nb+Ta≤0.15％；

When 2) forging stock heating, forging stock are heated in 800～850 ℃ thermophase, be incubated 3 hours, the heating-up time that rises to 1200 ± 20 ℃ of hot stages is 2 hours, is incubated 1.5 hours;

3) forging is shaped, first fire time steel ingot ejection during forging, touch steel ingot with less deflection, make coarse grain, block tentatively broken, second fire begins to increase the deflection of forging stock, and deflection is controlled at 30%～70%, vertical, horizontal upsetting pull forging stock 3～5 times, 6 center compactings of square forging stock 3～5 times repeatedly, forging ratio is reached more than 8, and the inferior final forging temperature of last fire is 850～780 ℃, last fire time deflection 〉=30%;

4) cooling and forging after-baking: forging is solid solution behind the natural cooling in air.