CN109468561B - Preparation method of GH3625 alloy strip - Google Patents

Abstract

The invention belongs to the field of metal material preparation, and particularly relates to a preparation method of a GH3625 alloy strip. The technical scheme of the invention is as follows: a preparation method of a GH3625 alloy strip comprises the following process flows: smelting, forging, hot rolling, solution heat treatment and acid pickling, and repeatedly carrying out cold rolling annealing and finished product heat treatment, wherein the forging and hot rolling temperature is 1120-1160 ℃, the total deformation is 35-70%, and the deformation per fire is 15-35%; the temperature of solid solution treatment is 1050-1150 ℃; in the cold rolling and annealing process, the deformation of each pass is 20-45%; the intermediate annealing temperature is 1050-1150 ℃, and the final intermediate annealing and finished product processing temperature is 950-1030 ℃. According to the preparation method of the GH3625 alloy strip, a cold rolling and annealing method is adopted, the deformation amount of a strip blank is controlled, uneven deformation is reduced, a uniform and proper structure is obtained, a qualified precision strip is obtained, and higher use requirements are met.

Description

Preparation method of GH3625 alloy strip

Technical Field

The invention belongs to the field of metal material preparation, and particularly relates to a preparation method of a GH3625 alloy strip.

Background

The GH3625 alloy Ni-Cr base solid solution strengthening type deformation high-temperature alloy takes Cr, Mo and Nb as main solid solution strengthening elements, and the maximum use temperature can reach 950 ℃. The alloy has wide application in foreign countries, has excellent comprehensive mechanical property, and can be processed into plates, rods, wires, belts and forgings. The method is widely used for manufacturing aeroengine parts, aerospace structure parts and chemical equipment.

For GH3625 alloys, there are several major problems:

(1) the material processing difficulty is large:

the GH3625 alloy is a difficult-to-form material, and has high contents of strengthening elements such as Mo and Nb, narrow hot working temperature range, low cold working plasticity and high deformation resistance. The difficulty of cold and hot processing is large.

(2) The research on the strip forming process is not systematic and the quality is not stable

The factors influencing the forming of the alloy strip are various, including multiple aspects such as materials, equipment, processes and the like, and the relationship among all parameters is complex. Since wide strips of thin thickness, 0.2mm x 200mm, are not previously produced from the GH3625 alloy, extensive systematic studies are required for the rational selection of equipment parameters, the optimum design of dimensions and materials, the amount of deformation in the various passes, the rate of deformation, and the control of stress relief annealing regimes, as well as the matching of these. For example, the pass deformation must be controlled to a certain degree to obtain a completely recrystallized structure, but too large deformation will cause strip hardening, performance exceeding, or cracking, and workability deterioration. In addition, because the requirement of the dimensional accuracy and the surface quality of the aviation strip is high, even if the strip can be formed and the structure performance is qualified, if the dimension does not reach the specified accuracy or the surface has defects of folding, cracking, pockmarking and the like, the strip still can be scrapped.

Disclosure of Invention

The invention provides a preparation method of a GH3625 alloy strip, which adopts a cold rolling and annealing method to control the deformation of a strip blank, reduce uneven deformation, obtain uniform and proper tissues, obtain qualified precision strips and meet higher use requirements.

The technical scheme of the invention is as follows:

a preparation method of a GH3625 alloy strip comprises the following process flows: smelting, forging, hot rolling, solution heat treatment and acid pickling, and repeatedly carrying out cold rolling annealing and finished product heat treatment, wherein the forging and hot rolling temperature is 1120-1160 ℃, the total deformation is 35-70%, and the deformation per fire is 15-35%; the temperature of solid solution treatment is 1050-1150 ℃; in the cold rolling and annealing process, the deformation of each pass is 20-45%; the intermediate annealing temperature is 1050-1150 ℃, and the final intermediate annealing and finished product processing temperature is 950-1030 ℃.

The GH3625 alloy strip is prepared by cold rolling at room temperature, and the rolling speed is controlled to be 0.3-1.0 m/s; in the cold rolling annealing process, ammonia decomposition on-line annealing is adopted, the strip speed is controlled to be 0.6-3.5 m/min, in the early cold rolling process of rolling, the small deformation amount between two annealing processes is 20% -30%, and when the distance between the two annealing processes is 1-2 rolling processes, the deformation amount between the two annealing processes is 30% -45%; and carrying out solution heat treatment on the finished product after finishing, and adopting ammonia decomposition on-line annealing at the treatment temperature of 950-1030 ℃ and the tape-moving speed of 0.6-3.5 m/min.

The preparation method of the GH3625 alloy strip comprises the following specific process flows:

(1) smelting: remelting by adding slag through vacuum induction;

(2) forging: heating to 1120-1160 ℃, controlling the deformation to 35-70%, and forging into a plate blank;

(3) hot rolling: heating to 1120-1160 ℃, controlling the deformation to 35-70%, and forging into a strip blank;

(4) solution heat treatment and acid washing: the temperature of the solid solution treatment is 1050 ℃ to 1150 ℃, the heat preservation time is 30 minutes to 60 minutes, and then the surface is pickled;

(5) cold rolling and annealing: in the cold rolling annealing process, in the early cold rolling process of rolling, the small deformation amount is 20-30% between two annealing processes, and when the distance between the two annealing processes is 1-2 rolling processes, the deformation amount between the two annealing processes is 30-45%; in the cold rolling process, each pass needs annealing, except the last intermediate annealing treatment, the annealing temperature is 1050-;

(6) solution heat treatment of the finished product: the solution heat treatment temperature is 950 ℃ to 1030 ℃, and the tape-moving speed is 0.6 m/min to 3.5 m/min.

The invention has the beneficial effects that: the GH3625 alloy strip is cold-rolled on a multi-roll cold rolling mill at room temperature, the deformation of each pass is controlled in the cold rolling process, the uneven deformation in the cold rolling process is reduced to the greatest extent, the uneven deformation of each pass of strip is reduced, the recrystallization of the structure of each pass of strip is realized, and the defects of cracks, pits and the like are avoided. And finally, carrying out large deformation and low-temperature annealing treatment for two times to obtain a fine crystal structure. The method has the advantages of high dimensional accuracy, smooth surface of the strip, raw material and working hours saving, simple process, economy and good benefit.

Detailed Description

Example 1

Smelting GH3625 alloy cast ingot by vacuum induction and electroslag, forging into a 20mm thick plate blank with a deformation of about 70% at 1120 ℃, heating to 1120 ℃, hot rolling into a 4mm strip blank, carrying out solution heat treatment at 1100 ℃ for 30 minutes, pickling, and then carrying out cold rolling and annealing on the strip for 5 times to roll the strip into a 0.7mm X200 mm strip. The rolling process parameters are shown in table 1.

Table 1 example 1 rolling process parameters

Example 2

Smelting GH3625 alloy cast ingot by vacuum induction and electroslag, forging into a slab with the thickness of 20mm at 1150 ℃ and the deformation of about 70 percent, heating to 1150 ℃ and hot rolling into a strip blank with the thickness of 4mm, then carrying out solution heat treatment at 1030 ℃ for 30 minutes and acid cleaning, then carrying out cold rolling and annealing on the strip for 6 times, and rolling into a strip with the thickness of 0.5mm for 200 mm. The rolling process parameters are shown in table 2.

Table 2 example 2 rolling process parameters

Example 3

Smelting GH3625 alloy cast ingot by vacuum induction and electroslag, forging into a slab with the thickness of 20mm at 1130 ℃ and the deformation of about 70 percent, heating to 1130 ℃ to hot-roll into a strip blank with the thickness of 4mm, then carrying out solution heat treatment at 1020 ℃ for 30 minutes and acid cleaning, then carrying out cold rolling and annealing on the strip for 9 times, and rolling into a strip with the thickness of 0.2mm for 200 mm. The rolling process parameters are shown in table 3.

Table 3 table of parameters of rolling process in example 3

The mechanical properties of the prepared GH3625 alloy strip are shown in Table 4:

TABLE 4 GH3625 alloy strip mechanical properties

Claims (1)

1. A preparation method of a GH3625 alloy strip is characterized by comprising the following specific process flows:

(1) smelting: remelting by adding slag through vacuum induction;

(2) forging: heating to 1120-1160 ℃, controlling the deformation to 35-70%, and forging into a plate blank;

(3) hot rolling: heating to 1120-1160 ℃, controlling the deformation at 80%, and rolling into a strip blank;

(4) solution heat treatment and acid washing: the temperature of the solid solution treatment is 1050 ℃ to 1150 ℃, the heat preservation time is 30 minutes to 60 minutes, and then the surface is pickled;

(5) cold rolling and annealing: in the cold rolling annealing process, in the early cold rolling process of rolling, the small deformation amount is 20-30% between two annealing processes, and when the distance between the two annealing processes is 1-2 rolling processes, the deformation amount between the two annealing processes is 30-45%; in the cold rolling process, each pass needs annealing, except the last intermediate annealing treatment, the annealing temperature is 1050-;

(6) solution heat treatment of the finished product: the solution heat treatment temperature is 950 ℃ to 1030 ℃, and the tape-moving speed is 0.6 m/min to 3.5 m/min.