Hollow forging piece profiling forging method of overlong-asymmetric-pipe-mouth-contained reactor coolant piping

Abstract

The invention discloses a hollow forging piece profiling forging method of an overlong-asymmetric-pipe-mouth-contained reactor coolant piping. The method comprises: (1), electroslag ingots are selected preferably as steel ingots and first heating is carried out; to be specific, after peeling and wound cleaning, the processed steel ingots are sent into a furnace and are heated to 1180 DEG C to 1220 DEG C and then heat preservation is carried out for 6 to 10 hours; after a blank is sent out of the furnace, upsetting, punching, and external circle rolling are successively carried out; (2), second heating is carried out; to be specific, the blank is put into the furnace and is heated to 1180 to 1220 DEG C and then heat preservation is carried out for 6 to 10 hours; and after core bar drawing is carried out, the processed blank becomes a hollow blank; (3), third heating, fourth heating, and fifth heating are respectively carried out; to be specific, the blank is put into the furnace and is heated to 1020 to 1060 DEG C and heat preservation is carried out for 4 to 6 hours; and after the blank is sent out of the furnace, the core bar is inserted into the hole in the middle of the blank and segmented drawing is carried out to obtain a hollow blank with two flanges; (4), sixth heating is carried out; to be specific, the blank is placed into the furnace and is heated to 1020 to 1060 DEG C and then heat preservation is carried out for 4 to 6 hours; and after the blank is sent out of the furnace, the pipe mouth is processed by pre-forging treatment by means of differential-temperature forging; (5), seventh heating is carried out; to be specific, the blank is placed into the furnace and is heated to 1020 to 1060 DEG C and then heat preservation is carried out for 4 to 6 hours; and after the blank is sent out of the furnace, the inner holes of the flanges are cooled by a differential temperature process and extrusion and finishing forging are carried out; and (6), the blank is corrected and the corrected pipe blank is bent and moulded by a bending die.

Description

technical field [0001] The invention relates to a profiling forging method for a main pipe hollow forging with super-long asymmetric nozzles, and belongs to the technical field of material forging technology. Background technique [0002] Reactor Coolant Piping (Reactor Coolant Piping), also known as the main pipeline, is the main artery of the nuclear power plant coolant system. There are several options for the design and manufacture of the main pipeline of PWR coolant in the world: stainless steel segmental casting (straight pipe adopts centrifugal casting), processing, and welding; Welding and forming; low-alloy steel split casting, inner layer surfacing stainless steel, welding and forming; stainless steel segmental forging, processing, welding and forming; stainless steel overall forging, processing (bending) forming. The steel used for the main pipeline of AP1000 / CAP1400 with a design life of 60 years is 316LN (ultra-low carbon nitrogen-controlled austenitic stainles...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the problems that the forging of solid forgings is relatively small in the forging process of the main pipeline, the grain size is difficult to meet the requirements, and the hollow forging cannot forge the full streamline nozzle alone, the present invention provides a main pipeline with super long asymmetric nozzles Hollow forging is a profiling forging method, which can ensure that the forging is uniformly deformed, obtains a fine and uniform grain size, and forges a super long nozzle

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