阅读说明：本技术 一种均匀细化固溶态gh4169合金锻件混晶组织的方法 (Method for uniformly refining mixed crystal structure of solid solution GH4169 alloy forging ) 是由 陈明松 王冠强 蔺永诚 马艳永 于 2020-07-01 设计创作，主要内容包括：本发明公开了一种均匀细化固溶态GH4169合金锻件混晶组织的方法。其方法包括以下步骤：(1)对具有混晶组织的固溶态GH4169合金锻件进行时效处理,时效温度控制在890～910℃,时效时间控制在9～24小时；(2)对时效处理后锻件进行连续降温退火处理,起始退火温度控制在1000～1040℃,退火时间控制在10～30分钟,终了退火温度控制在950～990℃。本发明提出的方法可以经济高效的将固溶态GH4169合金锻件混晶组织细化至ASTM10级以上。(The invention discloses a method for uniformly refining a solid solution state GH4169 alloy forging mixed crystal structure. The method comprises the following steps: (1) carrying out aging treatment on the solid solution GH4169 alloy forging with the mixed crystal structure, wherein the aging temperature is controlled to be 890-910 ℃, and the aging time is controlled to be 9-24 hours; (2) and (3) carrying out continuous cooling annealing treatment on the forged piece after the aging treatment, wherein the initial annealing temperature is controlled to be 1000-1040 ℃, the annealing time is controlled to be 10-30 minutes, and the final annealing temperature is controlled to be 950-990 ℃. The method provided by the invention can economically and efficiently refine the mixed crystal structure of the GH4169 alloy forging in a solid solution state to be above ASTM10 level.)

1. A method for uniformly refining mixed crystal structure of a solid solution state GH4169 alloy forging is characterized in that the method can uniformly refine the mixed crystal structure of the solid solution state GH4169 alloy forging to be above ASTM10 level through a combined process of aging treatment and cooling annealing treatment, and the method comprises the following steps:

step 1: carrying out aging treatment on the solid solution GH4169 alloy forging with the mixed crystal structure, wherein the aging temperature is controlled to be 890-910 ℃, and the aging time is controlled to be 9-24 hours;

step 2: carrying out continuous cooling annealing treatment on the forged piece after the aging treatment, wherein the initial annealing temperature is controlled to be 1000-1040 ℃, the annealing time is controlled to be 10-30 minutes, and the final annealing temperature is controlled to be 950-990 ℃;

the solid solution state GH4169 alloy forging in the step 1 means that a forging stock of the forging stock is subjected to solid solution treatment to eliminate phases, and the process conditions of the solid solution treatment can be as follows: the solid solution temperature is 1020-1050 ℃, and the solid solution time is 40-60 minutes;

the thermoplastic forming process of the solid solution GH4169 alloy forging with the mixed crystal structure in the step 1 needs to meet the following conditions: the deformation temperature is controlled between 950 ℃ and 1010 ℃, and the minimum value of the equivalent strain rate needs to be more than 0.0018s^-1The minimum equivalent strain value is greater than 0.2.

Technical Field

The invention belongs to the technical field of heat treatment of nickel-based superalloy materials, and relates to a method for uniformly refining mixed crystal structure of a solid solution GH4169 alloy forging.

Background

The nickel-based high-temperature alloy is one of the most widely applied alloy materials in the field of aviation at present, wherein the GH4169 alloy is widely applied to manufacturing key parts such as turbine disk casings, compressor disks, blades and the like of aeroengines due to higher strength and plasticity, good corrosion resistance and oxidation resistance and good fatigue performance.

The relation between the performance of the material and the microstructure is inseparable, the mechanical properties such as strength, fatigue performance and the like of the material can be improved to a great extent by refining the microstructure, and the structure is uniformly distributed, so that the whole forge piece can show uniform material properties. Therefore, in order to obtain a high-quality GH4169 alloy material, the microstructure evolution needs to be regulated and controlled. At present, in the thermal deformation process of a forging, the dynamic recrystallization degrees of different strain regions are inconsistent due to the uneven deformation of a blank in the thermoplastic deformation, so that the tissues of all parts of the forging are uneven, and the inside of the forging shows different and different material properties in different regions. Moreover, the uneven deformation in the forging process is difficult to solve by adjusting technological parameters. The existing process for improving the mixed crystal condition of the forging structure is to perform pre-aging before forging deformation to precipitate a delta phase, and regulate and control the recrystallization behavior of the structure through the particle-excited nucleation and pinning effects of the recrystallization behavior of the delta phase relative structure, but still cannot eliminate the uneven structure of mixed crystal. Therefore, the method is a new idea for controlling the static and sub-dynamic recrystallization behaviors of the structure by carrying out heat treatment on the forging so as to achieve the purpose of refining and homogenizing the grain structure. However, no mature process exists at present on how to realize the homogenization and refinement of the uneven structure of the solid solution forging by heat treatment after forging. Therefore, an economical and efficient new method is urgently needed to be invented, and the method can effectively improve the fine grain degree of the forged structure of the solid solution GH4169 alloy and can obviously improve the integral nonuniformity of the structure.

Disclosure of Invention

The invention aims to provide a method for uniformly refining a solid solution GH4169 alloy forging mixed crystal structure, which is characterized in that the method controls the recrystallization behavior of the structure by regulating and controlling heat treatment process parameters in the process of an efficient heat treatment process path, so that the uniformity and the refining degree of the solid solution GH4169 alloy forging mixed crystal structure are remarkably improved, and the problems that the process path economy and the grain refining efficiency are not comprehensively considered in the prior art are solved.

The scheme for solving the problems is as follows:

step 1: carrying out aging treatment on the solid solution GH4169 alloy forging with the mixed crystal structure, wherein the aging temperature is controlled to be 890-910 ℃, and the aging time is controlled to be 9-24 hours;

step 2: carrying out continuous cooling annealing treatment on the forged piece after the aging treatment, wherein the initial annealing temperature is controlled to be 1000-1040 ℃, the annealing time is controlled to be 10-30 minutes, and the final annealing temperature is controlled to be 950-990 ℃;

the solid solution state GH4169 alloy forging in the step 1 means that a forging stock of the forging stock is subjected to solid solution treatment to eliminate phases, and the process conditions of the solid solution treatment can be as follows: the solid solution temperature is 1020-1050 ℃, and the solid solution time is 40-60 minutes;

the thermoplastic forming process of the solid solution GH4169 alloy forging with the mixed crystal structure in the step 1 needs to meet the following conditions: the deformation temperature is controlled between 950 ℃ and 1010 ℃, and the minimum value of the equivalent strain rate needs to be more than 0.0018s^-1The minimum equivalent strain value is greater than 0.2.

The invention has the beneficial effects that: the method fully utilizes the temperature, the time, the dislocation energy and the action mechanism of static and sub-dynamic recrystallization in the structure after relative forging, realizes the homogenization and refinement of the uneven grain structure of the GH4169 alloy forging under the high-efficiency heat treatment process path, and provides a new method for the jump of the overall structure quality of the GH4169 alloy forging.

The principle is as follows: and a large amount of second phases are separated out through the first low-temperature aging annealing treatment. In the second high-temperature recrystallization annealing process, a large amount of second phases provide nucleation sites for recrystallization, and the densely distributed morphological characteristics of the second phases can also effectively prevent the growth of dynamic recrystallization grains generated in the forging deformation process. In addition, high temperatures can effectively promote recrystallization nucleation, recrystallization growth, and delta phase dissolution by promoting thermal diffusion of atoms. Therefore, the nucleation rate of the grain structure is increased under the high-temperature annealing treatment, the excessive growth of the grains becomes more obvious, and the growth rate is difficult to control, so that the uniform and fine grain structure is difficult to obtain. In view of the fact that the recrystallization rate can be effectively slowed down by reducing the temperature and the growth behavior of the grain structure can be controlled by a small amount of precipitated phases, the heat preservation process is designed to be a continuous cooling process, the temperature and the influence of the recrystallization behavior of the relative structure can be effectively and cooperatively controlled, and the whole grain structure becomes thin, small and uniform. Finally, the aims of refining the crystal grains of the nickel-based alloy forging and improving the uniformity of the structure are fulfilled.

Drawings

FIG. 1 is a preparation process curve of a GH4169 alloy forging;

FIG. 2 is an initial structure of a GH4169 alloy forging stock after forging;

FIG. 3 temperature vs. time curves for dual annealing aging of GH4169 alloy after forging in example 1;

FIG. 4 the grain structure of GH4169 alloy after two-stage annealing aging treatment in example 1;

FIG. 5 temperature vs. time curve for two-stage annealing aging after forging of GH4169 alloy in example 2;

FIG. 6 the grain structure of GH4169 alloy after two-stage annealing aging treatment in example 2;

Detailed Description

The invention is described in detail below with reference to the drawings and the specific embodiments.

The invention relates to a method for economically and efficiently refining the structure of a GH4169 alloy forging, which takes a typical industrial GH4169 alloy forging blank as an object in all the following embodiments.