A method for ultra-fine grain rolling of large-scale superalloy rods

Abstract

The present invention relates to the field of mechanical processing, in particular to an ultra-fine-grained rolling method for large-sized high-temperature alloy rods, comprising the following steps: rolling tool design, specifically including roll design and guide plate design, and setting the roll as a hyperboloid-like circle The table-shaped roll is specifically: the generatrix of the roll is formed by connecting two curves; one side of the guide plate is set as a curved surface; the structural deformation zone: the curved surfaces of the two guide plates are placed opposite each other, and the two rolls are placed between the guide plates. The area surrounded by two guide plates and two rolls is a deformation zone; the deformation zone with equal ellipticity of structure: the ellipticity in the deformation zone remains unchanged; the rolling feeding method is selected: the pouring rolling mode; the invention provides a An ultra-fine-grained rolling method for large-size superalloy rods, through the design of hyperboloid truncated cone-shaped rolls and curved guide plates, and the construction of equal ellipticity deformation zones, can be produced under the premise of significantly suppressing the Mannesmann effect in the core. severe plastic deformation.

Description

technical field [0001] The invention relates to the field of mechanical processing, in particular to an ultra-fine-grain rolling method for large-size high-temperature alloy rods. Background technique [0002] Ultrafine crystal / nanocrystalline materials and their preparation technology are one of the research hotspots in the field of material science. Research in this direction embodies people's efforts to continuously improve the strength and toughness of polycrystalline materials through continuous refinement of grains. Among them, the research results of severe plastic deformation (Severe Plastic Deformation, referred to as SPD) technology are eye-catching. [0003] At present, the mainstream SPD process includes five methods: high pressure torsion (HPT), equal channel angular extrusion (ECAP), cumulative stack rolling (ARB), multidirectional forging (MF) and torsional extrusion (TE), among which: [0004] (1) High-pressure torsional deformation: While loading a pressur...

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Problems solved by technology

[0009] (6) An equidistant spiral rolling method for large-sized high-temperature alloy ultra-fine-grained rods (application number 201810172810.3), using forward tapered rollers to perform equidistant rolling of round billets. Technical parameters in the forming process: The feeding angle is 19-21°, the rolling angle is 15-17°, the roll speed n is 20-40r / min, the diameter reduction rate is 4%-16%, the pass ellipticity is 1.18-1.35, etc., but, This method has shortcomings such as serious uneven deformation and small deformation, which needs to be further improved

[0014] (1) During the ECAP deformation process, the blank is in full contact with the mold, and the friction force is large, so the forming load is large, the finished product size is small, and the material utilization rate is low, the production efficiency is low, and it is difficult to realize the preparation of large-scale ultra-fine-grained materials required by industrialization

[0015] (2) The HPT forming load is huge. The existing forming equipment generally does not have the loading capacity of more than tens of GPa for industrialized large-scale products, and is only suitable for the forming of ultra-thin products such as films. Usually, the blank before deformation is Φ10-15×1- 10mm cylinder

[0016] (3) The ARB process is limited by the volume of the deformation zone and the uniformity of deformation, and the thickness of the deformation zone is only mm level

At the same time, since the prepared ultrafine grains are elongated grains in the shape of cakes, their mechanical properties are worse than those of three-dimensional equiaxed grains.

Therefore, limited by the loading capacity and uneven deformation, ARB can only prepare ultra-thin sheets

[0017] (4) Due to the serious deformation inhomogeneity of MF and TE, the grain size is uneven, the stability of the grain structure is poor, and the performance is reduced, and it is also impossible to prepare large-size forgings

[0021] Comprehensive analysis shows that the ultra-fine-grain process of superalloys mentioned in existing patents or papers is currently limited to laboratory research due to the degree of refinement and deformation uniformity, and it is difficult to prepare large-scale industrial-grade overall ultra-fine grains (Φ60- Φ500mm) material

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