Die tooling and forging method of straight pipe forging billet for nuclear power main pipeline

Abstract

The invention discloses a mold tooling for a straight pipe forging stock for a nuclear main pipe and a forging method. The mold tooling comprises an upper mold for forging a shape anvil and a lower mold for finishing a tube nozzle, wherein the upper mold and the lower mold are in fit connection through a location groove. The invention further discloses a forging method for the straight pipe forging stock for the nuclear main pipe. the method comprises the steps of with austenitic stainless steel serving as the stock, turning an ingot leading plate and a ingot surface layer and performing carbon planning on fillets; performing pre-deformation on the turned white ingot surface; performing twice upsetting, drawing and log marking cogging on the forging stock; performing a tube body and a tube nozzle flange, wherein the melting down temperature is preserved in a range of 950 DEG C to 1050 DEG C; performing finishing on the obtained forging stock. By means of the mold tooling and the forging method, by the finishing operation on the forging stock through the mold tooling, the mold tooling is simple to operate, the forging stock shape can be finished, the forging machining allowance is reduced, the product machining period is shortened, and the product manufacturing cost is reduced; enough deformation of the tube nozzle is guaranteed, grains are controlled and refined effectively, and the product quality is improved.

Description

technical field [0001] The invention relates to a mold tooling and a forging method of a straight pipe forging billet for a nuclear power main pipeline. Background technique [0002] The third-generation advanced AP1000 pressurized water reactor nuclear power technology designed by Westinghouse Corporation of the United States is an updated model of the second-generation and second-generation plus nuclear power technology in the world. Its main advantage is that its service life has increased from the previous 40 years to 60 years. The stacking capacity reaches 1.25 million kilowatts. The main pipe of AP1000 is changed from the second-generation and second-generation plus stainless steel segmented casting welding form to ultra-low carbon and nitrogen-added austenitic stainless steel with nozzle integrated large-diameter elbow. Each circuit includes two hot sections and four cold sections. section, five undulating tubes, and because of the use of integral forged tubes, there...

AI Technical Summary

Problems solved by technology

Due to the large amount of deformation during the forging process, the forgings are prone to cracks, and air cooling is used, the crack cleaning cycle is long, and the deformation of the last fire, that is, the eighth fire is often difficult to guarantee

And the actual product grain size is only 3.5-4 grades, which is slightly less than the required ≥2.7 grades.

This method produces forgings with large machining allowance, high manufacturing cost and long production cycle.

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