Tissue control rolling process for wrought superalloy GH3044 plate

Abstract

According to the structure control rolling process for the deformed high-temperature alloy GH3044 plate, the technical advantages of pure smelting of the high-temperature alloy and precise rolling of the structure control large-deformation plate are fully combined, the problems that the GH3044 alloy plate is poor in structure uniformity and coarse in grain are solved, and the material yield and the mechanical property of the alloy are improved; wherein in the electroslag remelting process, a slag system adopted by GH3044 alloy electroslag remelting is a CaF2: Al2O3 binary slag system and has the advantages of being simple in slag system component, convenient to prepare, low in cost and low in labor intensity, the structure control precision hot rolling process is adopted, the structure characteristics of the GH3044 alloy plate are effectively improved, and the GH3044 alloy plate is high in purity, small in plate grain size and uniform in structure; and the quality level of the GH3044 alloy plate is improved, and the use requirement of the high-temperature field is met.

Description

technical field [0001] The invention belongs to the technical field of deformed superalloy plate preparation, and in particular relates to a structure-controlled rolling process of deformed superalloy GH3044 plate. Background technique [0002] Nickel-based alloys are a type of metal material with a wide range of applications and high high-temperature strength among deformed superalloys. The main reason is that nickel-based alloys can not only dissolve more alloying elements and maintain good structural stability; they can also form coherent order The A3B-type intermetallic compound γ'[Ni3(Al,Ti)] phase is used as a strengthening phase to obtain higher high-temperature strength than iron-based and cobalt-based alloys. In addition, nickel-based alloys with higher chromium content have better resistance to corrosion. Oxidation and gas corrosion resistance; GH3044 is a Ni-Cr-based solid-solution-strengthened deformed superalloy containing a large amount of metal element W and a...

AI Technical Summary

Problems solved by technology

In addition, the hot rolling process and process of the GH3044 alloy sheet have a direct impact on its structure. Therefore, how to control the microstructure evolution of the alloy and finally obtain a homogeneous and fine-grained sheet by combining the smelting process, rolling process and heat treatment process has great significance. high technical difficulty

[0004] When the final rolling temperature of the GH3044 alloy plate is high, the temperature of the last rolling is also high, and the driving force of recrystallization is large. During the crystallization process, the cross-slip and climb of dislocations are relatively difficult, and high storage energy is accumulated in the local area of ​​the alloy plate, thereby inducing recrystallization nucleation. Through the growth process of new grains, a large number of dislocations disintegrate or disappear. After the alloy is softened and the recrystallization is completed, equiaxed grains are formed in the plate. On the one hand, if the final rolling temperature is low, coupled with the low rolling deformation temperature and small deformation in the final pass, the alloy plate will The internal recrystallization driving force is low, and it is difficult to produce dynamic recrystallization. Dynamic recovery is formed during final rolling. During the dynamic recovery process, the hardening caused by dislocation proliferation and the material softening process caused by the offset of different-sign dislocations generated by dynamic recovery exist simultaneously. , a fibrous grain structure will be obtained. On the other hand, the finish rolling temperature of the GH3044 alloy plate increases, and the longer the grain growth time after recrystallization, the larger the grain size; for example, at the finish rolling temperature The grains at 1050 °C are coarse, and the larger grain size will lead to a decrease in the strength of the alloy, which will adversely affect the mechanical properties of the GH3044 alloy sheet; in addition, when the final rolling temperature is lower than 980 °C, it will not only increase the deformation resistance of the GH3044 alloy , and reduces the plasticity of the alloy, it is easy to cause the size of the rolled plate to be out of tolerance, resulting in folding stool defects, and at the same time, the alloy cannot complete dynamic recrystallization, resulting in mixed crystal problems. Therefore, the appropriate rolling temperature has an important impact on the performance of the material; In addition, after the solution heat treatment of the GH3044 alloy plate, the internal structure is single-phase austenite and a small amount of MC and M23C6 carbides. However, with the increase of aging time, the amount of precipitation increases, and the carbide particles grow up, which will have a negative impact on performance. Therefore, in view of the above problems, it is necessary to improve