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Forging method for improving low-temperature impact resistance of duplex stainless steel

A technology of duplex stainless steel and low temperature impact, applied in the field of alloy material forging, which can solve the problems of high proportion of ferrite, ductile and brittle transformation, and decreased toughness of duplex stainless steel.

Pending Publication Date: 2021-11-19
AVIC SHANGDA METAL REGENERATION TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, since the ferrite phase in duplex stainless steel has a body-centered cubic structure, there is a phenomenon of ductile-brittle transition at low temperature. When the temperature is lower than the ductile-brittle transition temperature, the toughness of duplex stainless steel will drop sharply and embrittlement will occur.
The traditional production method of duplex stainless steel is to heat the steel ingot and longitudinally elongate it for forging. The obtained two-phase structure has a higher proportion of ferrite and a lower proportion of austenite, which leads to poor low-temperature impact performance. The two-phase structure in the duplex stainless steel obtained by the production method is approximately uniform and banded, and the structure direction is strong, which leads to its low transverse low-temperature impact performance, which cannot meet the use requirements of this type of material in a low-temperature environment.

Method used

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  • Forging method for improving low-temperature impact resistance of duplex stainless steel
  • Forging method for improving low-temperature impact resistance of duplex stainless steel
  • Forging method for improving low-temperature impact resistance of duplex stainless steel

Examples

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Embodiment 1

[0030] This embodiment provides a forging method for improving the low-temperature impact performance of duplex stainless steel, including the following steps:

[0031] (1) A duplex stainless steel cold ingot with a single weight of 1.69 tons and a height of 1.4 meters was heated at 50°C / h to 1250°C for 2 hours and then out of the furnace for upsetting forging. The deformation of upsetting forging was 35%, and then carried out Elongation forging, the deformation amount of the elongation forging is 40%, and a pretreated duplex stainless steel billet is obtained.

[0032] (2) Return the pretreated duplex stainless steel blank to the furnace and continue heating at 1200° C. for 10 hours, then take it out of the furnace for upsetting forging. The deformation of upsetting forging is 40%. After the upsetting is completed, a duplex stainless steel blank is obtained.

[0033] (3) Return the obtained duplex stainless steel billet back to the furnace to lower the temperature to 1100°C f...

Embodiment 2

[0037] This embodiment provides a forging method for improving the low-temperature impact performance of duplex stainless steel, including the following steps:

[0038] (1) Take a duplex stainless steel cold ingot with a single weight of 2.45 tons and a height of 1.46 meters at 90°C / h to 1200°C for 3 hours and then take it out of the furnace for upsetting forging. The deformation of upsetting forging is 20%, and then carry out Elongation forging, the deformation amount of the elongation forging is 50%, and a pretreated duplex stainless steel billet is obtained.

[0039] (2) Put the pretreated duplex stainless steel billet back into the furnace and continue heating at 1200°C for 10 hours before being out of the furnace for upsetting forging. The deformation of upsetting forging is 52%. After the upsetting is completed, a duplex stainless steel billet is obtained.

[0040] (3) Return the obtained duplex stainless steel billet back to the furnace to lower the temperature to 1050°...

Embodiment 3

[0044] This embodiment provides a forging method for improving the low-temperature impact performance of duplex stainless steel, including the following steps:

[0045] (1) A duplex stainless steel cold ingot with a single weight of 3 tons and a height of 1.42 meters was heated at 60°C / h to 1225°C and held for 2.5 hours, then released from the furnace for upsetting forging. The deformation of upsetting forging was 30%, and then carried out Elongation forging, the deformation amount of the elongation forging is 45%, and a pretreated duplex stainless steel billet is obtained.

[0046] (2) Put the pretreated duplex stainless steel billet back into the furnace and continue heating at 1210° C. for 9 hours, and then take it out of the furnace for upsetting forging. The deformation of upsetting forging is 50%. After the upsetting is completed, a duplex stainless steel billet is obtained.

[0047] (3) Return the obtained duplex stainless steel billet back to the furnace to lower the t...

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Abstract

The invention relates to the technical field of alloy material forging, in particular to a forging method for improving the low-temperature impact resistance of duplex stainless steel. The forging method comprises the following steps that 1, a duplex stainless steel cold ingot is heated to 1200-1250 DEG C, the temperature is kept for 2-3 hours, upsetting forging with the deformation of 20%-35% is conducted, then drawing-out forging is conducted, and a pretreated duplex stainless steel blank is obtained; 2, the pretreated duplex stainless steel blank is subjected to heat preservation for 8-10 hours at the temperature of 1200-1250 DEG C and then subjected to upsetting forging, the deformation of upsetting forging ranges from 40% to 52%, and a duplex stainless steel blank is obtained; and 3, the duplex stainless steel blank is subjected to drawing-out forging after being subjected to heat preservation for 2-3 hours at the temperature of 1050-1100 DEG C. The forging method is easy to operate and easy to implement, and by adopting the forging method, the purpose of improving the low-temperature impact resistance of the duplex stainless steel can be achieved.

Description

technical field [0001] The invention relates to the technical field of alloy material forging, in particular to a forging method for improving the low-temperature impact performance of duplex stainless steel. Background technique [0002] Duplex stainless steel, that is, stainless steel with two structures of ferrite and austenite in the solid solution structure. In most cases, ferrite and austenite each account for about 50%, and generally the content of less phases is at least a lot at 40%. Due to the excellent characteristics of both austenitic and ferritic stainless steel, duplex stainless steel has always been concerned and respected by technical personnel, and is widely used in important fields such as nuclear power, petroleum, chemical industry and marine engineering. [0003] However, since the ferrite phase in duplex stainless steel has a body-centered cubic structure, there is a phenomenon of ductile-brittle transition at low temperature. When the temperature is l...

Claims

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Application Information

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IPC IPC(8): B21J5/08B21J1/06C22C38/02C22C38/04C22C38/44
CPCB21J5/08B21J1/06C22C38/004C22C38/02C22C38/04C22C38/44C22C38/001
Inventor 叶强栾吉哲王守明刘军凯冯文静曹路明
Owner AVIC SHANGDA METAL REGENERATION TECH