Fine-grain forging method for large-size GH690 nickel-based alloy bar billet

Abstract

The invention discloses a fine-grain forging method for a large-size GH690 nickel-based alloy bar billet, and belongs to the technical field of forging. By using the composite technology of ingot billet homogenization and classified forging for preparing the GH690 nickel-based alloy bar billet, the grains of the bar billet for forging can be uniform and fine, thus meeting fine-grain structure homogeneity control requirements on final large-size alloy forgings; classified repeated upsetting-stretching cogging is performed on the basis of controlling a deformation temperature and the deformation amount of each heating number, the forgings are formed by hot upsetting by virtue of end part lubrication and horizontal restrain technologies, and rapidly cooled to eliminate grain coarsening caused by deformation heat effect, and finally, the forging structures with uniform carbides and fine grains are obtained.

Description

technical field [0001] The invention belongs to the technical field of forging, and in particular relates to a fine-grain forging method for a large-size GH690 nickel-based alloy billet. Background technique [0002] GH690 alloy (foreign corresponding brand Inconel690) is a Ni-Cr-Fe base corrosion-resistant deformation superalloy, and its nominal composition is (wt%) Ni-30Cr-10Fe. The high content of Cr makes it have excellent corrosion resistance under various working conditions. Its different product forms, especially large-size alloy forgings, have been widely used in nuclear power, aerospace, ships, petrochemicals and building materials. With the development of nuclear power and other industrial technologies and the increasingly harsh service environment, it is required that the alloy forging should not only have high corrosion resistance, but also have higher tensile strength and fatigue performance. The GH690 alloy only contains a trace amount of C (0.01-0.04wt%) and ...

AI Technical Summary

Problems solved by technology

However, the existing forging process is generally to directly forge the steel ingot without homogenization treatment, without repeated upsetting and drawing process, and the heating temperature in the forging process is too high, and the deformation of the fire is not strictly controlled, so that the produced The grain structure of the intermediate billet (bar billet) for large-sized alloy forgings is coarse and the carbides are uneven, which leads to difficulty in controlling the uniform fine-grained structure of the final forging, low yield, and unstable performance, which hinders the further application of the alloy

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